Mercedes-Benz M278 Cam Sensors and Solenoids Replacement (W221)

More Mercedes content today, this time on the W221 doing the cam sensors and solenoids. This is a PM item that I am doing just a hair reactively on this car, after some oil seepage started on the cam sensors and solenoids. Common M272, M273, M276, and M278 problem (and others) - the seal in the sensors between the oil-wetted area and wiring fails and allows oil to wick into the engine wiring harness. Caught early enough, no problem, left alone, and it’s an engine-out service and harness replacement. If you have one of these cars, definitely take the time to knock it out.
Thanks for watching!
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Parts Used
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Solenoid: amzn.to/3CVeh8u
Sensor: amzn.to/3kgs4zc
Requires 4x each for full engine on an M278. Also can recommend purchasing from FCP Euro when in stock, as their pricing is comparable to Amazon’s and they offer lifetime replacements on products they sell, at the time of filming this video).
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Special Tools Used
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Flex Head Wrenches: amzn.to/3o7J7Vd
E-Torx Ratcheting Wrenches: amzn.to/3EV6J6o
Stubby E-Torx U-Joint Sockets: amzn.to/3F9QlPB
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For business inquiries: [e-mail]
redonkilaus
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Notices
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Outro Music:
Avenza - Royal - • Video
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Download - fanlink.to/Royal
Spotify - sptfy.com/1n2Q
Legal disclaimer: Our videos are for educational purposes only. We will not be held liable for any loss or damage incurred as a result of any content communicated on this KZbin page.
By using the Amazon links in video descriptions you are helping support this channel. Thank you all for watching!

[@goranyordanoff3919]

Outstanding video. Every aspect of it is a blueprint for other presenters to model after: no annoying music, great camera angles/lighting, CLEAR CONCISE SPEECH, etc. Hope this guy gets a bigger following. Thank you.

[@redonKiLaus]

Thanks for watching, glad you enjoyed!

[@CorisWorld404]

I am so grateful that you posted this! I am going to tackle this on my car soon.

[@Iam_Yu627]

Had the dreaded p0366 monster show up today on my e550 coupe. Researched for solution and came upon this video. Freekin excellent. Thank you so much!!

[@samspace81]

outstanding tutorial! I used this to repair and prevent damage to my M157 in a 2012 S63

[@walterpaitoo8138]

man you're amazing. Just had this issue thankfully oil not leaking on the electric compartment. Easily replaced and working great now!

[@redonKiLaus]

Thanks for watching!

[@johnhempton425]

Thank you so much again for your video, I have tackled and completed this task the only thing i did different was to take the oil filter off before starting the right hand bank solenoids which made getting access to the lower one a bit easier. Kind Regards John.

[@redonKiLaus]

Thanks for watching, glad it helped and that you got it done!

[@karlkarl3604]

Thanks man. My X166 was leaking all over the place which reached all elec. harnesses. Replaced the 4 sensors & magnets, degreased the entire front engine, good to go. No codes & No leaks.

[@redonKiLaus]

Glad to hear you got it sorted! Thanks for watching!

[@daveh2612]

Was it throwing codes prior to you changing the sensors and magnets? Or did you just inspect them and noticed they were oily?

[@redonKiLaus]

@@daveh2612 No codes in my case, I just inspected since it is a known issue with these engines and I was planning on doing it anyway, just happened that they started leaking a few months before I was planning to replace when I checked them.

[@daveh2612]

@@redonKiLaus oh ok thanks. I just inspected my 89k GL550 and I have oil in two of my cam sensors and none of the actuator solenoids. Ordering all of them, thanks for the helpful video!

[@redonKiLaus]

@@daveh2612 Awesome, glad you're getting it taken care of!

[@jameshole4431]

Great video. Dealer wanted $1,860, will tackle😊 with FCP Euro supplied parts.

[@redonKiLaus]

Thanks for watching!

[@emilsierra3309]

Excellent video!

[@redonKiLaus]

Thanks for watching!

[@armandoortiz6943]

Just did mine this weekend, pretty easy. For the third bolt, i used an 8mm wrench. Took ten minutes.

[@redonKiLaus]

Thanks for watching!

[@yellowcon8726]

Great video I need to do it to Miami Sadie thank you, sir

[@XLPerformance666]

my 2012 cls550 got a code (P0014), should replacing these help to solve that?

[@GlitchedVR68]

Thank you for the video, I appreciate it so much. I found all my cps to be leaking (oil in sockets) and oil on the ecu pins. Would cleaning the ecu pins be exactly as you cleaned the sockets with contact cleaner and should I do both the pins as the socket that goes into the pins? How can I tell if the magnets are bad?

[@redonKiLaus]

Cleaning the ECU pins can be done with contact cleaner too. I will say this - often once the oil makes it to the ECU you are running on borrowed time as it can wreak havoc on the internal ECU components if it's made it that far. Be cognizant that you may have a large bill coming up for a wiring harness and ECU replacement...not trying to scare you, just a heads up. Also, when cleaning, try not to soak the connector on the ECU itself...contact cleaner inside it probably isn't good. I'm sure there's a test for the magnets, but I don't know off the top of my head...they're cheap so I'd just replace them personally. Thanks for watching!

[@judahisrael8241]

Great video, I changed all magnets and cam sensors. I now have a dtc P0016, for the crankshaft position sensor, bank 1 sensor A. Do you know where the crankshaft sensors are located. Much appreciated.

[@Advantaplans]

You said after you replace the sensors & magnets you may have a bigger problem if its leaking a week later, .....what would that be? Valve Cover Gasket?

[@MrStangdawg]

This is an absolute crazy issue for a manufacturer not being immediately on top of this. The better fix is that Benz actually came out with "sacrificial" harness connector to go between the sensors and the harness.

[@redonKiLaus]

I've heard that they finally did for this engine too, at the time of filming they only had a kit for the older M273. Crazy for sure. Thanks for watching@

[@thebajan7]

Fcp euro has them for the m278 now! I put them on mine last month

[@pinkyp2274]

​@thebajan7 before u put them on did u have problems starting CAR that's how you knew they where bad

[@user-um5zw1pk3s]

Great video. Have you taught about adding the pigtail wire to help with the oil leak on the connectors getting into the wire harness?

[@redonKiLaus]

I've been told they are available for 278/157 engines (they didn't used to be, only 273 V8s) so if I still owned the car, yes I would. Thanks for watching!

[@johnhempton425]

Hi, thank you for your amazing video, at how many miles or kms or age of vehicle should these problems arise, I am in Australia and have a 2013 W166 Ml500 which is a ML550 in America that has 80,000 Ks on it and was wondering when I should do the repairs.

[@redonKiLaus]

These issues typically show up in the 30-50,000 mile range, so I'd start planning on doing yours at this point and at about that interval. Thanks for watching!

[@RosSauce85]

What exact grease did you use to lubricate the o-rings on the magnets and solenoids? Would it also be ok to simply put the same oil filter back on since I recently had an oil change done? Thanks and great video!

[@redonKiLaus]

DuPont/Chemours Krytox. Not 100% sure on which variety. You should be OK to put the same filter back in as well. Thanks for watching!

[@elvismrsic6227]

Do you need to reprogram the computer or do anything after the replacement is done or just turn the car on and let it cycle?

[@BoostedHerm]

Hey bro, so I had the same problem of oil leaking into the harness and I just replaced the sensors with oem ones as well as doing a deep clean on the harness. The car is still misfiring and I’m not sure what to do as this is what the problem was. Any insight would be appreciated

[@redonKiLaus]

If the oil made it to the ECU, it may have damaged it. I highly recommend checking those connectors. That's one of the reasons why I won't own another M278/M157 car. Thanks for watching!

[@fixingproblems3183]

How many did you have on your car before you start to see the oil ?

[@Timur4593]

Informative video my friend, thank you

[@redonKiLaus]

Thanks for watching!

[@timchambers8230]

Just purchased a 2014 E63s with 50000km on it - I pulled the ECU to check for oil on the connector pins and there was oil in there. - so far no codes but will replace all four cam sensors and solenoids.

[@redonKiLaus]

Hopefully it won't damage the ECU and you get some years of trouble-free enjoyment out of the car. That's one of the reasons I won't touch an M278/M157 car anymore as far as ownership goes. Thanks for watching!

[@malekn.4490]

The black s550 got totaled ? 😳😢

[@ErnestoMunoz2075]

Awesome. 😃😃😃

[@redonKiLaus]

Thanks for watching!

[@vincentwhite775]

Did you have any codes or symptoms before you started? You had me worried at first when you mentioned removing the oil filter housing. I just had a new one put on recently.

[@redonKiLaus]

None at all in my case and the oil hadn't wicked into the harness at all really. Known issue so I did this preventatively. Thanks for watching!

[@chuemoua6834]

Is there a secret on removing the connector with gray sliding clip ? When I slide the tab back the harness is still on there like it’s glued on .

[@redonKiLaus]

You press the tab down to release it - assuming that's what you're doing, should come off easily. Thanks for watching!

[@floridatravelvideos]

Have you heard if Mercedes made pigtails for these sensors and magnets. Apparently they did make them for some of the older engines so the oil would leak into the pigtail which gave time to replace the pigtail before the oil made it to the harness plugs.

[@redonKiLaus]

From what I understand they do not and the older ones won't fit these either (different connectors). Unfortunate since I would've done them on mine. Thanks for watching!

[@floridatravelvideos]

@@redonKiLaus Yeah thats unfortunate because I just learned from the dealer that this happened to my M278 shortly before they sold me the car. The previous owner took it in and the service record shows that it was an extensive repair as the oil destroyed pretty much everything attached to the harness. They are telling me it will happen again since Mercedes didn't come up with any way to prevent it from happening again like on the older engines.

[@redonKiLaus]

@@floridatravelvideos The only way you can really prevent it is preventative maintenance/replacement of the sensors and solenoids...the new revisions do indeed leak still, though. Unfortunate for sure.

[@hasoncr8525]

Hey i want to know which part it will be bank one sensor ? The one on the top or bottom

[@redonKiLaus]

Bank generally refers to the side of the engine, not which camshaft. Service manual is the only place I can think of to find that info. Thanks for watching!

[@techguy1678]

My 2013 S550 with 54K miles was recently in the shop for service and they noticed some wetness underneath the car. When diagnosed closely, it looks like all my solenoids and cam position sensors have been leaking. Primarily, it's the connectors on the driver's side that are soaked in oil. I've ordered parts to mitigate this but what concerns me is, is my main harness on it's way out.. I have no error codes, car drives absolutely fine.

[@redonKiLaus]

Unless you caught it very early, it will likely wick up to the ECU and begin causing electrical issues eventually. An unfortunate achilles heel for the 278 and 157 engines. Could be quite a while before that happens, but could happen nonetheless. Thanks for watching!

[@techguy1678]

@@redonKiLaus I did end up replacing all 8 sensors along with installing sacrificial harnesses. It wasn't too bad, actually, my driver's side timing cover was leaking which I ended up fixing as well. I installed a new cover and sealed using the oem mb sealant. Thanks to the tools you suggested, I did buy everything except for the 18 point wrenches, those will be added to my tools soon.

[@gabrieljimenez1893]

I’ve been looking at 13 cls 550 everything you mentioned has been replaced on it at around 45k miles it had cam adjuster solenoids replaced ecu reprogramed wiring harness repaired exhaust replaced oxygen sensor replaced starter and alternator replaced it sits at 80k miles 20,500 is it safe to buy it ? seemed like it had been well maintenanced other than that

[@gabrieljimenez1893]

@RedonKiLaus

[@redonKiLaus]

@@gabrieljimenez1893 I wouldn't personally - if the harness was repaired (ie cleaned) and not replaced, there will likely be an oil wicking issue in the future. Thanks for watching!

[@MercedesMechanic]

Once you replace them, would you need to replace them again anytime or is this a permanent fix to this problem?

[@redonKiLaus]

It's something I'd replace on about a 50k mile interval myself. Thanks for watching!

[@Phuong_Nguyen_]

Any knowledge in the front cover leak?

[@redonKiLaus]

Not something I've dealt with at all on these. Thanks for watching!

[@vmax673]

FCP Euro has a updated kit that you can buy to prevent them from leaking

[@redonKiLaus]

I've heard, definitely the route I'd go nowadays. Thanks for watching!

[@jayuddin9590]

Is the steps the same for the v6 s350 w221 engine?

[@redonKiLaus]

It's more or less the same - may be simpler. Thanks for watching!

[@ernanv24]

Will this be the same in gl63 with m157 engine?

[@redonKiLaus]

Almost identical process, and same issue, yes. Thanks for watching!

[@dn9822]

With engine M157, there is no way to put the gear wrench onto the bottom crew of the left solenoid on driver side.

[@redonKiLaus]

It should be packaged the same as this one, unless turbos are larger and prevent removal. I've heard of folks with 63 AMG cars getting these off without removal of a turbo though, so something should be possible. Thanks for watching!

[@mikimiki195]

As of 2023 fcpeuro is selling harnesses for this issue I believe they’re $25 I still don’t get it how oil travels trough harnes

[@Kellionaire]

Please what’s the name of the part

[@redonKiLaus]

Interesting, that is good to hear! The oil wicks up the wires via capillary action, similar to how water wicks up a paper towel if you dip it in a cup of water. Thanks for watching!

[@BrianSmith-oq5uu]

What were the indications you had that one was seeping in the very beginning?

[@redonKiLaus]

I didn't know I had one seeping - just a known issue on these vehicles and preventatively checked. Saw that one was, and replaced ASAP. Thanks for watching!

[@snowgo5922]

Jumping ship from another brand opening the door to Mercedes M278. Being ignorant to the sensors/connectors and the engineering aspect behind its design I have come to my own conclusion based on others conversation. Having no idea what I’m talking about here are some run-on sentences: The sensors are introduced to internal pressures that eventually overtake the integrity of the sensor’s function allowing oil to invade into the sealed connector cavity channeling the oil through in between the wire and its protective outer coating wicking under pressure the unseen oil making its way to the ECU. As this baffles my analytical mind the “sacrificial” wiring harness jumper allows for the oil to enter the jumper, but terminates it somehow stopping it from corrupting the OEM harness connector that so many talk about being introduced to oil if not addressed as a preventative measure with this jumper. Am I close at all of being on the right track? Awesome videos you have out and we all thank you more than you know and for those who have mentioned the sacrificial wire harness in these videos are all gentleman.

[@redonKiLaus]

@@snowgo5922 You are on the right track and essentially have all correct. The sacrificial harness will, at best, stop the oil flow, but worst case, will at least keep oil from the main harness and with frequent checks can be changed out if need be once a leak occurs and runs the sacrificial one. Thanks for watching!

[@Nousername750]

I received a p0017 code. Is that the sensors?

[@redonKiLaus]

It could be. Thanks for watching!

[@jeffrobbins2318]

Good video and thanks. One question, why are the timing cover bolt heads painted blue. I know their supposed to be one use only but are they that colour on a new engine or has there been previous work done in that area.

[@redonKiLaus]

I believe all replacement bolts are blue to indicate that the check valve recall has been performed (at the very least). In my case, not only has that been done, but it's also had camshaft adjusters and timing chain tensioners done previously among a couple other services at the same time. Thanks for watching!

[@dn9822]

If what you said is true then I am lucky. All the bolts on my timing cover are blue. Yay!!!

[@hz4331]

The old sensor had different structure the new with green O ring is skinner 😮

[@redonKiLaus]

And unfortunately they both fail eventually. I wish they would create a working design for long-term use. Thanks for watching!

[@dowhatyougottado916]

So where’s the oil leak coming from, is it out of the magnets?

[@redonKiLaus]

Magnets or cam sensors, more often the latter. Thanks for watching!

[@holeshot1721]

Funny thing is i have the 6 cylinder version of this engine which is n/a and two cylinders less and has the same exact sensors bad guess this video is gonna gain alot of attention as all cars nearing the 150k mile mark and 15 years old these parts fail! Now i took out my spark plugs and they were ngk mbenz with blue writing on them. Now im almost positive that the only way to get the benz symbol and blue writing on ngk plug was from the factory! So kudos 🎉 to the spark plugs for making it 150k miles now they looked worn but the car ran perfectly up till one coil went. Cylinder 1 i always run 93 hi octane as this car is cranky with anything lower! Grrr whats your results guys! I put in all 6 new coils and 6 plugs and now i have a coil secondary circuit cel light for each cylinder! Back to the drawing board!

[@redonKiLaus]

You may need to look into spark plug clocking for your CEL - these spark plugs need to be clocked very precisely due to the cylinder design and necessary flame travel direction. Lots of info out there on that topic. Thanks for watching!