The Mercedes Benz OM651: Is it a good engine?

[@nickjohnstone9939]

One of the best engines I've ever owned and still own. The OM651 is definitely capable of achieving 500,000kms to 1,000,000kms.

[@DolphinDivingChamp]

500000 kms is not very much.

[@nickjohnstone9939]

@@DolphinDivingChamp ...Haha. you're hilarious. It says 500,000kms to 1,000,000kms. Plenty of taxi examples in Europe have covered this distance. If you don't think 500k KMs to 1 million KMs (300k miles to 600k miles) is a lot of mileage, you've got problems. That distance rivals the very best other reliable brands, like Toyota make. Many Mercedes Diesels have lasted the test of time for years. 1 million KMs not enough? Try a 1976 Mercedes taxi that has 4.6 million KMs, gifted to the Mercedes Museum.

[@100pyatt]

Absolutely agreed this motor is quite good and very efficient too🎉

[@cassk9999]

My sprinter om651 in england i use for courier work has 591,000 thousand miles. i believe that's over 1 million kilometres for you americans

[@danishchoudhry302]

Still nothing compared to the OM646 and 647

[@MomedLelmo]

Dude you just cleared to me everything about OM 651 a thank you is worth saying for the effort❤

[@janrutjes6936]

I have an GLC250 with the OM651 engine. It has now done 250k km and during my trip from France to Senegal, passing through Spain, Morroco and Mauretania I ran into ADBlue problems. Seen the fact that no parts are available in Senegal and the fact that you cannot restart the car if you drive more than 800km with this fault I had to find a local solution. I finaly found a guy that simply ereased the ADBlue system from the engine controller software. I have no issues anymore and do no longer need to fill-up with the Eurea fluid.

[@philliproberts2737]

Amazing breakdown. This is one of the best videos and great detail on any engine. Thank you so much.

[@nobenznofun9139]

I've gone through a few cars with the OM 651 at work over the last 10 years and had no problems to speak of! If you get the Euro 5 emissions OM 651 you don't have to deal with DEF and all these sensors. And except for a leaky waterpump or some other minor wear items no major issues. The highest mileage I had was 741000km or 460k miles and it still ran just fine. They got a really bad reputation due to problems with the injectors when they where first released, however, MB fixed that issue under warranty and switched to different injectors for later models which have been working fine ever since. I'm surprised this unit has piezo injectors, I have actually only seen them with solenoid valve injectors so far.

[@evilsideracing]

haha my sprinter only has 130000km and showers me with problems every couple of days

[@hayest4468]

Tuned out all of the garbage and swapped in straight pipe for DPF. She runs like a champ and have driven it all over the country. One of the VERY few modern diesels I would recommend assuming you delete everything. Also have an om648 with 312k+ miles so far.

[@ionutmih97]

Only problems with these engines are: -the owner -2 holes chain tensioner in early models needs to be replaced with 4 hole version -oil pressure switch solenoid needs to be removed or plugged They really only need clean oil and coolant

[@kenty6973]

I have owned a GLK250 since 2014, brand new. Never had any problem because I do all maintenance by myself since day one, no matter what the free service dealer offered me. Change oil (229.31/229.51) every 5K miles, exchange Adblue (VW DEF, not PeaK) every 2 years and coolant (Zerex G48) every 4 years including ATF (134FE) and gear oil (Castrol 75W90) and you are good to go. Recently Mercedes keeps calling (can you imagine they called me 4 times a day?) and emailing me about the new emission update free of charge with up to $4K cash bonus to me. Mercedes also sent me 2 free Mercedes fancy speakers so that I can bring my GLK250 Bluetec in for free emission updates. This sounds too good to be true. and I declined. I know if I get this free emission update plus $4K cash, I will have bills of $40K repairs down the road, waiting for me. I will never let the Mercedes dealer in the USA touch my Mercedes DIESEL.

[@garethoswald3392]

4 hole tensioners also fail. Due to same inherent fault. The inverted mount oil filter housings. Drain back to sump overnight. Delay in oil feed to tensioner accelerates. Fail in one way valve in tensioner. Then the cycle of fail starts to eventually chain stretch The start point of failure is rattle after oil change. Thats the sign to replace tensioner fast. It might stop the fail cycle.

[@ionutmih97]

@@garethoswald3392 the tensioner will hold tension (and the oil in it) for a very long time. 100% if om651s which have failed in any way had oil changes at terribly long intervals.

[@garethoswald3392]

@@ionutmih97 bought car with 7500 miles. Changed oil twice at least a year. Using merc correct spec oil. And merc filters. Not exactly a poorly maintained engine. Now at 70000 miles. Chain just changed. Old one was stretched almost 2 cm longer. Original tensioner replaced. And it was the 4 hole updated one. Switched stop start in menu to off day after i bought car So what did i do wrong ? Its quiet for now. But i reckon rattle will return. In my mind oil filter drain back to sump is the real problem. If you research jeep cars with same engine in usa. They are on it. Making aftermarket kits to fit in oil filter housing. To stop drain back. But unfortunately the oil filter housing on jeeps are different. So kit wont fit our om651 engines.

[@ionutmih97]

@@garethoswald3392 never heard of such case, mine was at 110k miles when I bought it, had less than 1cm stretch, its a 2011 so it had the 2 hole tensioner. No grooves on the cylinder head.. tried new tensioner, but it would still sound bad during cold weather startups. So engine out, new oem everything + oil pump and that oil pressure regulator plug installed. In your case it’s just unfortunate, some do fail early but it’s less common than you might think. If the engine is otherwise in good condition just do the timing and keep driving, you’ll get your money back on saved gas. Maybe you have a 204hp version and drove it harder? Don’t know

[@brauer777]

Engine is great the emission system was a pain in the butt. Twice a year a trip to the dealer for NOx sensors. Finaly gave up and the DPF fell off. No more problems.

[@stephenenglish]

It was also put in my 2017 Infinity Q50 with the Mercedes 7-speed gearbox. Great engine, 215bhp, 368 f/p torque.

[@servicefast-cars]

Excellent overview of the OM651 Engine, thank you.

[@jfaz]

Thanks for the great video! I just purchased a 2021 Sprinter with the OM651 so will be excited to see your future videos. I have two relatives with W212 E250’s that seem mostly trouble free so I opted for this OM651 over the OM642. Of course now with just 15K miles I got a CEL code P20EE so it’s at the dealer barely still under warranty. We’ll see. Best wishes on your GLK!

[@jamesogara2219]

Fantastic episode -- very helpful. Re super-fast warm air coming from the vents on cold days, I noticed the same thing about my 0m642 engine (2012 E class) but always assumed there was some electrical heating element.

[@DasMoorhuhn]

You are right, there is an electric heater. These engines take round about 20km to get warm.

[@Alonzo_4]

I own a OM651 and do agree that when stuff breaks it’s piece by piece. 1 lamdasonde 2 abs sensor it’s always sensors that are stop functioning. It drives just wonderful…one of the best running engines I’ve had

[@ADMINM-ld7vu]

abs has nothing to do with the engine, and the lamda arent the engines fault either

[@halexic1]

Around 360,000km in 14 years (not too much) - here is the list what was replaced on engine: Malfunctioning parts: - Water pump at 170.000km (leak) - ESP/ABS electronics at 250.000km (dead) - Few sensors (O2, NO2 - dead) - Chain at 330.000km (rattling started) - Battery (1st after 10 years, second after 4 years) Preventive maintenance: - One injector replaced at 310.000km (preventive maintenance) and other 3 cleaned - Oil inter-cooler at 350.000km (preventive maintenance) - inlet manifold (plastic part) replacement at 310.000km (preventive maintenance) - Starter (working but noisy on start - preventive maintenance) at 330.000km - Alternator refurbished at 350.000km (preventive maintenance)

[@marvinwilliams7938]

What's the deal with the ESP/ABS electronics at 250kkm? My ESP/ABS goes out if I accelerate very softly and drive around or go up hills. If I accelerate with a moderate strength and drive around in cruise control, usually no issues. Turning off the car and back on again fixes it, wondering if I'm gonna get the same thing soon

[@halexic1]

@@marvinwilliams7938 ​Had some sort of similar problem where occasionally ABS/ESP stopped working with warning on a screen and when I restarted the car it started to work ok (like it was self repaired). At the end it was found out that module's electronics was a problem and when they replaced it, never saw this again for the last 5 years.

[@halexic1]

Exactly the same problem I had (message miracleoisly dissapeared many times and return back) and after the replacement all good.

[@matejfilipovic3646]

And what are your toughts on this car? Is it worth buying. Im getting a nice offer for 220d 2014year. Im hearing from my local service that 651 engines are bad but i just think they are hard to work on.

[@halexic1]

@@matejfilipovic3646 I just bought S205 and will probably sell my S204 and it will be very hard for me to sell it because it is still a great car. OM651 in my case was a great engine and never left me on the road because engine had a problem. Had few preventive maintenance replacements between 300.000km and 350.000km and it is super smooth again and I have a feeling it could go another 300.000km without mayor problems. I would buy this car if it is in a good condition - 2014 is last production year. Great looking car, it has some specific nice smell (quality materials inside) every time you get inside it and it is always a pleasure to drive it. Check with some mechanic before buying - take down protective plates bellow and check the state of the bottom of the car - check if fuel lines and break lines are started to rust, check back subframe if it is rusty (Mercedes should replace that as a warranty), check whole suspension. Check service history, how often they changed oil (this shows a lot if owner liked his car), see how often they replaced fuel filter and brake fluid (good owner replaces this every 2 years). Check if they replaced transmission and differential oil (factory says "lifetime" but every good owner will replace this in every 50.000km). Try to start it in the morning when it is cold - do you hear strange noises (chain rattle - ready for replacement, starter can be also heard if it is at the end of life when you start the engine, or some pulleys). Check water pump if it is leaking (lifetime around 150.000km), check cooling liquid in plastic reservoir - are there any traces of oil (if yes oil-intercooler should be replaced). My "new" S205 is 5 years old and yesterday I had a first drive I already hate these things: - I don't have nets to storage water and small stuff at the back of front seats and at co-driver side on middle pillar - I don't have in trunk additional storage space that can be opened (left and right) and to keep cleaning and diagnostic stuff - Double bottom in the trunk is very small - can not put spare wheel like in S204 - Don't have electronically opened tailgate (at least not on car key) - maybe it have inside the cabin (didn't check - yesterday was first ride) - Don't have memory that save seats, wheel, mirrors position like in S204 - Don't have option to set climate temperature for passengers on back seat - Don't have manual shifter but automatic - On the other side new one has Burmester, AMG line outside and inside, 4Matic and also has trailer hitch like my S204 - Good things - drives great, more nimble (less heavy than S204 - more aluminum parts), enterior is looking good but I don't think it match quality and materials of S204

[@jeremyocampo1529]

Very good video, I bought a GLK250 with 180k miles back in march. Now it has 187k miles I have replaced the intercooler hose along with the boost elbow, and the intake pipe.

[@MBDieselFreak]

my 2007 E320 bluetec had both the turbo hoses blown out shortly after i bought it loo. the rubber goes bad over time due to oil exposure.

[@janrutjes6936]

I have an GLC250 with the OM651 engine. It has now done 250k km I recently had the ratling sound at startup and had the timingchain tensioner replaced. This however did not do solve the problem, and I had the chain and camsprockets changed and everything is OK now.

[@xTurtleOW]

I bought 2017 C class with this engine in january and so far its been alright (especially compared to my other 3 audis I had before), there has been quite alot done to the car but most of them were paid by the dealer and I plan to keep the car for a while. Stuff done: New battery A-service Transmission fluids coolant replaced all filters replaced broken right indicator nox sensor adblue pipe water pump center console trim which was broken fixed steering knocking ( not sure what they did but it was fixed)

[@itumelengmahaole5890]

How well is it holding up and what's the odometer reading?

[@xTurtleOW]

@@itumelengmahaole5890 its now 176000km (I bought at 150k) after the fixes listed nothing has broken, last problem was 6 months ago so its been alright

[@ohnoitisnt]

The UK W906 sprinter had the 646 from 2007, then the 651 from 2012. The low power 646's like the 311 last as long as the vans (half million miles? million?) but the similar hp 651's tend to go bang by 250. We're comparing a euro4 and euro 5 engine though. The injectors are different between those engines (fittings and connector swapped). Ed: Also, super annoyingly, MB changed the engine mounts and bellhousing on the 651 era engine/gboxes so they are no longer bolt compatible with the old stuff, which is lego back to some point in the 80s....

[@bjorntorsten8241]

My 2014 sprinter with the OM651 has 320,000 miles and runs so smooth and like new, it was a fridge van delivery vehicle so constant stop and go in city traffic. Mine is non dpf fluid.

[@garethoswald3392]

Your sprinter van likely has duplex double row timing chain Bulletproof. Till mercedes thought. These engines are lasting to long. Lets introduce. Simplex chains. Reduced longevity build in.

[@antomee1301]

Thanks for the new mb diesel content!

[@deboshirik]

Great video !! and a nice efficient engine. On my GLK (rear drive, 200CDI, no adblue) - only had 2 problems: intercooler air hose (black one) - typical crack and eventual burst takes place typically after 70k miles and is easy to replace, the other one is Mass Air Flow Sensor (MAF) mulfunction - and I will attepmt to clean it myself using MAF cleaner - hopefully I'll get itback to normal operation, otherise - need to replace.

[@petem79]

Change engine oil and filter in every 10k mile or about 15.000 and keep the tensioners from clogging from bad lubricants.

[@petem79]

15000 km:s

[@justfunandpopeace]

What lubricant you recommend? I am at 140k , oem recommendation is 229.51.

[@giorgiogiorgi932]

mobil 1 esp 5w30

[@anyau]

My car has 210k miles. Yearly serviced since 2014. It died in a flood but I am going to rebuild it.

[@wikeroy]

My OM651 has 198 000 km on it. I have done two things on it except regular maintenance. 1) Tightened the 12 (?) bolts on the valve cover. It's made of plastic an without metal inserts for the bolts. So how long will they keep the tension....it leaked quite a lot. 2) Changed the DPF diff pressure sensor. Very easy to do. I love the 2010 C-class, but of course don't like to think about all the plastic parts in there. I can only hope for the best, and keep changing the oil every 8000 km. I plan to change the transmission oil this summer. It was last changed at 60 000km. 😮😮😮

[@eminusta1715]

9nm ?

[@evilsideracing]

I own a W906 with this engine and let me tell you. Its the worst shitbox i have ever owned. There is always something wrong with it and it only has 130000km on it.

[@andyx7488]

I own a c220d 2015 with this engine and on the start in the morning I hear a rattling noise but n not every day. It happens once a week or more. I asked the guys in the shop where I do my car service and they saying is not timing chain. What could it be? Im a bit concerned

[@legancki_vlog]

Did you fix it @andyx7488?

[@andyx7488]

@@legancki_vlog no. It stopped now that the weather got warmer. On the service they told it’s not timing chain. They told me to do an engine flush.

[@samsea9075]

​Mine was fixed by replace the tensioner only whith the upgrade one whith 4 holes , done before 5 months no more rattling , easy to replace , and not expensive.​@@andyx7488

[@giorgiogiorgi932]

its either the lifters or a known issue in the turbo manifold at cold start. no need to fix it

[@youtoobe169]

By the way, this was an awesome video! Very informative

[@100pyatt]

No VVT turbo on OM651 is a huge advantage to begin with in addition to the stellar fuel efficiency

[@trevorwhite9068]

What frequency of changing the timing chain tensioner is recommnded as preventive maintennace?. as it is an engine out job, surely the chains, guides and possibly drive sprockets would also be replaced as a precaution?

[@ADMINM-ld7vu]

These were available in sprinters and v-class/vito aswell!

[@umutgokcay]

Please advise, there is observed oil residue in the intake pipe connecting to air filter. İts not much , but threw error of maf sensor after changing to new oil service periodically. We cleaned the maf sensor and pcv valve cover and error disappeared. However im not sure if i change the pcv valve cover completely or should I check turbo if leaking oil..we.ç checked turbo clean side had no oil in it. But central turbo pin is moving slightly

[@mrtickles5982]

OM646 owner here. Highly doubting about upgrading to OM651. The OM561 NOX sensors are prone to failure. I've seen sensors go bad in one year. There's two of them in the car. About 800 euros per sensor. Only OEM sensors are a wise choice, since the aftermarket ones last 1-3 months. Have to be changed at the dealer or no warranty for the part. Having an AdBlue system in your merc can potentially cost you 2000 euros or more per year.

[@pauliuspaulius240]

and replacing those nox sensors is a hell of a job...

[@kaito1412kiddo]

@@pauliuspaulius240 DPF delete. Problem solved.

[@Davoodoox1]

@@kaito1412kiddo I have run one year now with AdBlue delete and the motor runs like new. I had to do the delete it because the NOX sensor broke down all the time. The NOX sensor prices feels like a scam.

[@JaMinge]

Euro 5 engine/ variant and you won't have those issues only EGR and DPF because DEF/SCR was brought in for the euro 6 engine regs. The Euro 6 upstream sensors are easy enough to change however the down steam is always a b*stard due to the AdBlue corroding/ seizing the sensor in the port

[@AI-qd4vb]

NOX sensors are not prone to failure and the adblue variants will not cost you 2000 euros per year even in the worst of cases. Who told you all of this nonsense? Show me one single proof of any om651 with the adblue system catastrophically failing more than once. Most dont even fail once. This is not PSA/Stellantis... I'm in a group with more than 1000 owners of this engine and theres been 0 cases of adblue failure, 0 cases of NOX sensors failing, 0 cases of timing chaing failures,... The only mildly recurrent issue is the dpf clogging and its always the case of excessive city driving

[@Benrainbowman]

Well I hope based on how many views this video got. You make more om651 content

[@marktowill2828]

Thank you for your excellent video. I have the same Mercedes and agree a 100% with your prediction about the emission system. Here in Canada the DEF can freeze downing the system . It was deleted 6 months ago before the Mercedes class action law suit . It was a last resort, as I had paid $ 800 each for two nox sensors. I love the engine now that I know the check engine light will not be coming on the emissions system at least! Can I get your opinion about changing the oil to a more diesel friendly [zinc] since it will no longer effect the emission system. I do my own oil changes with Pennzoil 0-W30 at 6K intervals.

[@MicroAngelo1]

Best OM 651 information video of all time!!!!💪

[@JonnyWedde]

DPF codes on this engine are tricky. I went down a rabbithole on the codes. The reason fore the codes was a leak in the boostpipe. After changing the boostpipe, the car sortet out the codes. Watch out fore clogging in the intake manifold, around 250 000km. If i remember correct the code is someting A200 ***. I changed the intake manifold. About 10hour job (im a amature), MBDieselFreak refered to 5 hours.

[@giorgiogiorgi932]

thats a must do. same for chain, and clutch+flywheel (I have manual one). also remember alternator regulator. and engine mounts every 100-150k km. good engine but delicate and very expensive to work on, because its a mess of components and lack of space.

[@Subliminal3117]

Thanks for the information. Im going to buy one next week, but could not decide whether to sell it for massive profit and keep my slow boring 1.4 hdi peugeot 206+ or keep it and enjoy some great ride quality because I drive a bit (28000km yearly - approx 500km per week)

[@alban-agushi]

I own w212/2.2/2014, having issues with NOX sensors...

[@youtoobe169]

I have a 2014 GLK250 with 160K miles. It's an amazing engine. Unbelievable power for a small diesel, great fuel economy and 100% reliable.

[@evilsideracing]

reliable? Mine is not reliable. Its my second Mercedes and its awful just like my first. Too bad BMW doesnt make vans.

[@youtoobe169]

@@evilsideracing Did you buy it new? What issues have you had?

[@evilsideracing]

@@youtoobe169 i bought it 3 years old. Its a 2016 Sprinter Van and despite it only having about 70000mls on it ive been having tons of problems. Turbo, egr, sudden loss of power that nobody every found out whats causing it, a/c compressor... and then with the rest of it its not looking better: broken door latches, broken window actuator, radio working whenever it wants, water intrusion, broken brake calipers, stuck e-brake linkage, pdc not working.... Id understand if i would beat the living life out of it, but i always treat my vehicles well and maintain them. Its only Mercedes that ive been having such serious trouble with. I had an E-Class before, it was the same disaster. Ive had multiple BMWs before that i put a lot of miles on and those never gave me that kind of trouble.

[@youtoobe169]

@@evilsideracing Sorry to hear you've had such problems. German cars can definitely be hit or miss.

[@kenty6973]

I have a 2014 GLK250 with OM651 since new. All the issues you mentioned can be taken care of if you do the following: 1. Timing chain rattling - Change the oil with MB approved 229.31/51 oil, and change every 5K miles. 2. Water pump - Change the coolant (MB blue) every 2 years. 3. Front axle - I removed the drain plug and installed a drain valve so that I can drain and refill every 2 years. There is no fill plug there. 4. Emission & DEF - Change the AdBlue (DEF) every 2 years. I mean to evacuate the old DEF and put in new DEF. I do not buy the DEF from auto parts stores or gas stations, and I cannot afford the genuine MB AdBlue either. So I always order the VW AdBlue from VW dealer which costs me 1/3 of the Mercedes one. Again use the MB approved 229.31/51 oil to maintain the emission system. I bought the 229.31/51 oil from Walmart which costs the same as my Camry oil. 5. AGAIN Emission & DEF. No this is not a typo. I will take my OM651 for a road trip (300 miles each way) once every year to regenerate. The vehicle all of a sudden will consume more diesel than normal and pooped out what was stored. This is what is called diesel scandal. Human beings do that too when they want to fart in a public place or somewhere else. My overall experience of ownership till now is NEVER/EVER take it to the dealership in the US for service. They may know how to work on gas cars, but definitely have no clue of a German diesel. Secondly DO NOT respond to the dealers emission recall. The MB dealership called me 6 times a day and offered me FREE emission modification and offered me $4000 cash to go there. They called me in various languages and the calls lasted about 2-3 months. Finally they gave up. Meanwhile MB sent me 2 fancy speakers with MB logos to encourage me for the recall. I know there is NO free lunch. If I would go there to get their free lunch plus cash, my GLK250 would be in a junk yard now.

[@fix-and-drive-diy-repairs]

The timing chain at the back of the engine! What hell? I need something so simple I can easily fix myself!

[@MBDieselFreak]

After doing a couple timing chain jobs on older benz's that have the chain on the front..... I'm dropping the engine out on every other timing chain Job I'm doing. So much easier lol

[@fix-and-drive-diy-repairs]

@MBDieselFreak I read a few comments and if it's reliable as they some say and you have tools to deal with the problems when they arise, maybe it is not bad!

[@BibiMizrah]

If guides break then engine needs to come out. If guides are fine some people do the chain and the tensioner from the top of engine which is much easier.

[@pauliuspaulius240]

​@@MBDieselFreak older benz's have normal strong chains in front that do NOT need to be replaced like these 651 chains from bicycle... Basically 651 engine is complicated and poorly designed comparing to older generation engines

[@AI-qd4vb]

@@pauliuspaulius240 older benzes have no power lol, wth are you talking about? The 651 chains are absolutely ok and barely fail at all. Yeah, such a poorly designed engine that can achieve half a million kms easily, output more than 200hp and keep fuel economies of little more than 6L to 100. And all of it while complying with all the contamination laws from the EU, the strictest set of them on the planet. What a terrible design, yeah...

[@josephzhang195]

I bought a 2013 GLK250 BlueTec new and still have it, now it's over 220,000km, over the 11 years, all the issues were emission parts, NO2 sensors, AdBlue lines, AdBlue heaters...etc, the engine itself is very good and runs smoothly and powerfully. However, after the a recall to tune the engine and transmission, I found the engine has much less power since then and the 7G transmission can no longer shift smoothly as before.

[@giorgiogiorgi932]

you shouldnt do the recall. I think you did the pollution recall... they change egr timigs.

[@jianuon]

I would agree with the info in this video. What he can't tell you is... if you get it tuned. All you emission problem goes away. Oem has a really bad throttle lag. It can be scary sometimes. The tune will solve all those problem. Just shut off emissions. Lol. Fuel economy is amazing in my sprinter van. Unbelievable mpg

[@51madmitch]

As long as you do regular oil and filter changes with good oil, the chain should last a long time, I know a Mercedes mechanic, neglecting it is what causes the problem, so many thousands of these engines used, and as always a few problems on line and it gets blown out of proportion, hydraulic power steering much better feel, AMG keeps it for this reason !!! good video, thanks.

[@MBDieselFreak]

@@51madmitch REALLY love the electric steering rack. The simplicity of the system is a benefit over hydraulic as the cars age as well.

[@haraldsjonans3724]

What a really helpful and interesting video. It has given me a great overall picture of the OM651 engine. Sadly it didn’t help me to diagnose an issue that I’m having with mine. I’m hoping you may be able to shed some light on a loud “ticking” noise I’m getting from the front/top of my engine? I’ve changed and serviced the injectors and replaced the hydraulic valve lifters. It still makes the same noise. The engine has done 230,000 miles and still pulls fine. I’m reluctant to use it till I can diagnose this issue. Any ideas before I look to pulling out the engine? Many thanks

[@nico-toscani]

You're completety wrong about the chain issues- It does wear out, so as the tensioner, the chain can stretch pretty much, also the guides can break into pieces. If you still not convinced- The cam gear breaks also. Please look it up yourself- there's a guy in Poland, he's on yt too - p.a.r.d.i. mercedes (try without the dots). Search for 651, see for yourself.

[@MBDieselFreak]

Found your comment! Looks like KZbin liked it this time lmao. About the video you referenced, I just watched it! Don't speak the same language so can't understand what he's saying, but I did see the evidence of severe stretch. I did notice however the abnormal oil varnish discoloration on everything. You typically see that from gas engines running non-synthetic oil. My guess would be that engine was not running correct spec oil, or was suffering from oil starvation. I just saw a video last night of a om651 in a W212 with 330k km, the chain had virtually no stretch and the sprockets/chain looked considerably cleaner.

[@E39M5SPEED]

Intake manifolds are prone to cracking at lower bolt and leaking. Since they are plastic.

[@mrrossi739]

i have a 2013 C220cdi with the 651 and the crank just started tapping a week after having the oil changed, replacement engines are so expensive for these

[@51madmitch]

This engine water pump has a shroud that is pulled round the impeller by vacuum, the impeller still turns but not in the water, as shroud covers it, when block temperature goes up the shroud/cover starts to drop down letting water pump impeller circulate the water, it helps warm heater up quickly of course, but I’m told the main reason is hot engine more efficient burn of fuel, less pollution better MPG quicker.

[@MBDieselFreak]

@51madmitch I'm having an issue with the vacuum controlled water pump right now, working on fixing it. Video should be coming on that in the future.

[@Silv3rfox]

I had a problem with the chain ,I changed the tensioner ,works is by hydraulic pressure and I replaced the chain guides plastics because they were broken # I advise if you have rattling noise be careful with the chain guide to prevent te damage to engine my car was about 160000 miles 🎉 I put new chain ,new tensioner guides plastic things new oil ,filter 2k was the parts and the job itself 😅

[@abdulamiraalubaid3056]

hi you have great knowledge in this OM651 engine, can you show the location of the EGR please?

[@JaMinge]

The EGR sits on top of the engine above the inlet manifold. It is mated to the cooler as a single unit when removing (at least on the sprinter vans, may be different on other model vehicles). Send me a message and I shall send pictures of it both on and off the engine.

[@simeunovicm]

What is that pulley for where power steering pump supposed to be?

[@MBDieselFreak]

Just an idler pulley for the belt. Doesn't drive anything.

[@simeunovicm]

@@MBDieselFreak thank you

[@emrahceylan7157]

Sprinter euro 5 a651 motor tamiri yapildiktan sonra 2000 3000 rpm arasinda titreme var. Sebebi nedir ?

[@fuffoon]

I have a valve cover leak. It will get fixed next month along with silent blocks and front lower control arm. The shop is half staffed with courses for new generation EVs going on.

[@BadMuflon]

I just had the check engine light on for the last 2 days and its the o2 sensor. Car has 68000kms

[@sprinterfix]

Hell yea, those updated return line fittings are 100 times bettter, never break when taking off, new 642s have the updated return line too.

[@stevepalstra]

great to see your back , very ,very good vids, keep up the good work . youtube needs more guys like you for us D I Y ers .

[@damiantuttle1348]

It just looks like an absolute nightmare 😮

[@MrToomas85]

Piezo injectors? Your ecu is bosch and therefore you should have solenoid injecors. Delphi also changed piezo to solenoid and it is written on ecu sticker.

[@K0ub1]

OM651 C200 CDI here with oil leak issues. Fixed: - valve cover gasket - oil cap seal - injector washers - oil pan glued with a sealant Possible leak sources: - oil filter housing - timing chain tensioner I still have a visible oil leak dripping down from the passenger side, above the oil pan and the oil plug area. What would be the source? I doubt it's the tensioner, getting it replaced soon. Can the oil filter housing leak down from the passenger side?

[@MBDieselFreak]

Did you check the crank case vent valve?

[@K0ub1]

yeah that's not leaking. Possible other leak sources could be: - Exhaust manifold nuts - under the turbine, oil return line from turbine to block - somewhere around the oil dip stick location @@MBDieselFreak

[@speededul]

Oil Filter Housing is very common also

[@davidwhite9473]

The Oil cooler is a very common failure, and leaks as you have described its cheap to buy a replacement but a few hours labour to change it. Happened on My e250, make sure you replace the cooler itself and not just the seals as they can crack internally or so i was told

[@MBDieselFreak]

@@davidwhite9473 thanks for mentioning this! I haven't heard of oil cooler issues. One tip though, when I was looking up the part, you CAN buy a seal kit on eBay that includes all 9 seals that go between the block, coolant housing, oil cooler, and filter housing. Saves a bunch of money. I would go that route unless the plastic filter housing is busted.

[@Izrealeu]

religious 10 k km oil changes and they will treat you well.

[@MomedLelmo]

16:00 something went wrong with your catalyst😂?

[@brauer777]

First can is the DOC and the second one is the DPF

[@averagedev7768]

651 is just a normal mercedes engine that needs VERY HIGH QUALITY OIL due to longer service intervals

[@censoredviking]

My oilcap on my s205 250d is also leaking 😅

[@nico-toscani]

what happened with the comment I left couple hours back? Did you remove it? It was about the chain problems.

[@MBDieselFreak]

Haven't removed anything! Did you leave it on another video possibly?

[@nico-toscani]

@@MBDieselFreak ok, I will write again.

[@nico-toscani]

@@MBDieselFreak Happened again- I mentioned about another channel as a reference- is this the reason why this comment has been removed ?

[@MBDieselFreak]

@@nico-toscani it's possible, I think there might be like some kind of anti spam filter with KZbin that prevents external links. PM me if it's a question

[@user-zh9sd8ql8l]

Hi I am from Sydney Australia, I have an ML250 & CLS250, both with the OM651, the CLS has done 118,000miles (no AdBlue). I have replaced the alternator, turbo hose & a DPF pressure switch, its has been an extremely reliable. Unfortunately the ML250 130,000 miles with AdBlue, has had numerous issues, 2 water pumps, Oil Cooler, transfer case chain. Nox Sensors DPF, & catalytic converter were replaced under warranty. Its finally running well, I think the old Nox Sensors (replaced under a recall at 80,000 miles) caused a lot of issues with the DPF.

[@adambordas5024]

Huhh, that's complicated. For now I'm staying with my OM648. :)

[@attilato7173]

Ive have the Infiniti Q50 with the OM651 engine single turbo not twin like this one( Or the GLC Twin turbo). regular oil changes (@15,000 Not 25k is better ....

[@MrRocktuga]

You can talk to any MB mechanic in Europe, and most of the time, when a OM651 is rattling (and waaaay before that example on startup), the cure is to replace the chain, tensioner, chain guides and often the sprockets, as all of it is worn out. By replacing the tensioner only, you’re waiting for a disaster to happen, and they do happen. The OM651 is one of the worst Mercedes diesel engines _ever_! Btw, I had one, and when I first started to hear the timing chain (way quieter than that example), it took it to a MB dealer, and they replaced all those things that I mentioned. The car had around 80k miles. But you could find engines with the same mileage which had already broken the chain, with a new engine tab presented to the customer, in a car fully maintained by the dealer since day one. I’m happy that I got rid of mine (I was happy to give it to May ex-wife 😉).

[@MBDieselFreak]

You're sure that the chain, sprockets, and guides are worn out as well by the time the tensioner needs replacement? Because I've seen numerous forum posts as well as KZbin videos demonstrating that the chain and sprockets were still good and didn't warrant replacement. Dealerships will ALWAYS replace complete assemblies in a repair, they will never just replace individual internal components for fear that other affected systems may fail in the future. This is why dealerships replace entire transmissions or engines rather than attempting to repair them. Nearly every single example I've seen of catastrophic engine failure on the om651 has been from user error, like running it out of oil or never changing the oil. But then again, the only examples I've seen are from mechanics/owners that speak publicly about it.

[@100pyatt]

Sounds like you got duped by the garage. Lol. The 651 is a stellar motor just don't do the idiotic 10k OCIs 🤣

[@tshepomokoena502]

Well it looks it ddnt like u,mine is like heaven on earth

[@zenonjurgelevich7376]

Well, Taxi’s in Germany , Denmark etc. equipped with these engines. Average figure on the dash board is 500K +

[@gacha24]

the chinese Elon impersonation was spot on xD

[@Salman-sc8gr]

Try replacing the egr,what a silly design.

[@FMJ777]

I have this engine in my Infiniti q30s (UK)

[@Fubarpapa]

No oil pressure and lubrication problems?

[@drasim881]

Disaster worse to work on had. Nothing but problems

[@АрсенДзанаев-р3л]

Спасибо вам 👍

[@farai209]

I own 2 w204s & one is at 200K Miles & the other at 96K miles so far so issues.

[@julijanojulijano8137]

i live my life happy again after selling my mercedes with om651

[@dzhanetpamuk9426]

Good boy

[@swecias]

Vacum watter pump ? What a hell are youu talking about, nonsense

[@nikolayri]

Oil cooling is not making sense on this engine. First trying to cool the oil to 100 Deg Celsius, using coolant at temperature 108 C. Second - the water pump stops turning at speed to save fuel. Oil pump decreases debit as well. Oil pressure drops and oil temperature goes up. Engine seizes not even being under load. Had one and seized and repaired too many times. Mercedes said the have to replace the whole engine block. Replaced with a petrol engine.

[@Robert-o5q5b]

Absolutely tthe worst bag of shit I ever had. The water leaks piezo injectors. Simplex timing chain At the rear god knows why they did this. Then the twin lanchester balance shafts. why put dual mass flywheels and balance shafts on a diesel.

[@MBDieselFreak]

@Robert-o5q5b crazy the different experiences people have. Sprinter owners in here saying 500k km of trouble free ownership best engine they've ever had. Others saying they've had the engine rebuilt 3 times in 200k miles. Really weird. I've only had my 651 8 months, but it's been dead nuts reliable.

[@AI-qd4vb]

what? why put balance shafts on a diesel? You hit your head lad? What vibrates more than a diesel engine? And whats wrong with the timing chain? Its in the back because its not supposed to be serviced or replaced and only runs the valves and nothing else.

[@Backwardlooking]

👍🏻🇺🇸✌️🏴󠁧󠁢󠁥󠁮󠁧󠁿

[@JE-sc7jm]

The biggest enemy are def

[@autonomousindividual7780]

Focus you F--K. AvE fan?

[@holdischbjorn7158]

Junk.

[@100pyatt]

Hardly 🙄🙄🙄

[@ClintThomson_1962]

If an engine isn’t made in America it’s not worth your time…. Junk!

[@AI-qd4vb]

cmon boomer, who left you off your pills?

[@kwasiejohnson5889]

can I get an email for you please I have a lot questions ... mine has lost power and doesn't launch anymore