Mercedes S Class with oil in wiring harness what is the cause and correction?

[@chrisbort6083]

Do not let Discovery ruin this dynamic. Y'all are great as is.

[@Carpenterjoh65]

Amen! I hate the drama those people manufacture. I've seen them ruin a few companies.

[@markw5805]

I hate the idea of him having a show…he doesn’t need them to grow his channel and it will always be about the drama

[@Resistolitin]

Discovery ruins everything.

[@harryash11]

1000% couldn't agree more. Remember they approached you for who you are. Don't let overzealous producers push you to not be yourself!

[@will_mcfarland]

Name one good reality show. I can’t. They will make Dave unwatchable 100%. Counting down the days that I watch these guys.

[@roguewarr4662]

Dave as a 30 year GM tech and 17yr Fleet tech , I am very surprised you have not seen this in your past. This phenomenon is quite common with GM connectors , oil wicking from sensors that are in a engine ,trans area where some kind of pressure build up is common place .Same as battery acid wicking down the cable from the battery to the starter . The need to change a completed engine harness on the Mercedes S Class is totally unnecessary , along with the PCM or what ever Mercedes calls there module . If the PCM is working to pick up the fault ,then it does not need to be replaced .Hopefully new update cam sensors and good can of clean will fix this guys issue . I Think every Dealer tech at some point or another has stumbled across a oil soaked connector while fixing another problem . Dave your old school thinking in a High Tech environment with your techs is very refreshing to me . That's why I and many like me watch your channel (Discovery show to come ) .

[@michaelschneider-]

To the power of 10 .. Agreed.

[@stevendegreef93]

He has seen it before, it’s show. What do you know duh

[@DavesAutoCenterCenterville]

Yes, we replaced the sensors and cleaned the connectors and replaced crankcase breather and shipped it 👍

[@skateboardcraze]

​@DavesAutoCenterCenterville Im no mechanic, but it's just 2 wires running up to the harness? Cut both wires and remove an inch or two of the wire shield. Now use glue shrink wrap to re seal, removing almost all the air clearance in the shield where the oil seeps through. If or when they come back 😮

[@Conservator.]

@@skateboardcrazeI’m no mechanic either and that sounds like a clever patch (if you don’t fix the cause) or a clever fail save (if you do fix the cause).

[@byronn.2885]

I love how he called the mechanic over that was working on it. That is a proper show of respect for another man’s work. This is one of my favorite channels.

[@696969stone]

What,s you other favorite channels if it,s have something to do with repair or build cars// Chris

[@kofidonkor151]

I love when people admit that they don't know everything and are willing to learn, this clearly shows you are a leader.

[@zaprodk]

Well clearly the Mercedes tech needs to read up on electrical knowledge and chemistry.

[@58fins]

I've been a Benz tech for 30 years, and we started seeing this on the 722.6 five speed automatic, electronically controlled transmission a few years after they were introduced in 1997. It would wick fluid all the way up to the transmission control module, sometimes ruining them.

[@BadMuflon]

Does it happen on the newer 7g and 9g tronics?

[@davidjones8680]

This channel just gets more and more interesting by the day. You sure employ some great knowledgeable people Dave.

[@DavesAutoCenterCenterville]

I appreciate that!

[@Markytroyer]

​@@DavesAutoCenterCenterville yep had a older s500 that sucked transmission fluid all the way up to the tcm and took out the tcm ,also a common problem on those is the water drain under the wipers clogs up and water enters the car at the passenger fire wall area and destroys the sam module under the back seat . I don't work on very many Mercedes but had one with these problems and learned that from a identifix Mercedes tech

[@seanthompson8071]

In this world, your people will make you or break you. Hire the best, develop them and treat 'em right!!

[@mbtech2003]

24 year Mercedes tech here. Not the first engine with this issue. There was a recall on all 272,273 engines too for this issue. Now seeing it in 276/278 next gen engines. Replace all 4 can sensors and cam adjusters, solenoids, blow out engine module clean pins and harness. Good to go. And yes also happens with 722.6 transmission plugs. Also used in dodge transmissions. Fun stuff. Made a lot of time and hours fixing these cars.

[@AnontheGOAT]

Don’t forget sacrificial pigtails between the harness and solenoids/adjusters.

[@jimjames6990]

The owner gets a 5000 bill after all that. For get it.call the tow. Im buying a Toyota

[@mbtech2003]

@@jimjames6990if you can’t afford a 5k bill. Don’t buy a Mercedes. 🤷‍♂️

[@xFrxdx]

@@mbtech2003 Difference between a once and a while 3-5k bill compared to everytime u go in, JDM vs German

[@mbtech2003]

@@xFrxdx I know plenty of mercs running around that do not do this. Also now plenty of “jdm” cars that do.

[@ricksweetser1683]

25 year tech and 6 year technical training course developer / instructor here. To illustrate this phenomenon: The O2 sensors no longer get their ambient O2 content through a hole in the sensor housing. Instead, the ECM/PCM produces a pulse current in the wiring to the sensor which carries the ambient air to the sensor. Any system that has a varying current can produce a variation of this pulse current which can facilitate movement of air (or oil) along the wiring. Capillary action will move it some distance, but not all the way to the control module. Add a bad PCV causing the crankcase to pressurize, and you exacerbate the problem.

[@psfanboy79]

Wow…that’s insane

[@stopthephilosophicalzombie9017]

I don't understand the physics of that at all. I thought oil was a non-polar substance.

[@joelarata7572]

I work at the dealer, and we just do exactly what you said, replace the cam sensors, clean out the connectors spray out the ME and kick it down the road. Only if the oil is dripping out of the engine control module will we do a harness and a ME control module. What you guys have is not that bad. Also, make sure you check the connectors at the O2 sensors. They’re pretty common for getting oil in them when this happens. Good luck.

[@aravel13]

exactly,ive dealt many times before with the same issue,i have never ever replace the harness or the control module,just take little time to clean it good,and ofcourse replace the sensors and good to go,never worked for the dealer stealer,but as the guy said,do the really replace all that?!?if thats the case somebody should be responsible for that robbery

[@Slotcarking]

Love the way you treat your employees like family Dave! Great info & i fwded this video to my Mercedes buddies!

[@realdevbro447]

Family the greatest scam in the business.

[@dednsyde]

Please keep the uploads coming. Love this channel!

[@DavesAutoCenterCenterville]

Thanks! Will do!

[@fredmalito9869]

Well, I’m glad to see it’s not just me that experiences these issues! I own and operate a 2006 International 9400i with a Caterpillar C13 engine. This engine has wiring harnesses that pass through the top of the engine to operate the fuel injectors and intake valve actuators. Oil intrusion into these harnesses is a known issue, and the oil will flow through the connector at the valve cover, into the outside harness, and then travel down to the ECM and destroy it. These intake valve actuators are not known to be ultra reliable, but any time a fault code for an actuator or injector pops up, I immediately suspect that it is not one of these components, but oil intrusion. It is almost to the point that these wiring harnesses are a maintenance item to prevent damage to the $6000 ECM. Thankfully these harnesses are very easy to replace, it takes about two hours to do both the internal and external, which includes putting a meter on the injectors and actuators to monitor their resistance. It cost about $1200 to do the job. I always whinge and moan about Caterpillar part prices, but I guess I said shut my mouth and be thankful I don’t have Mercedes engine (sneering at you, Freightliner!).

[@simonm1447]

Daimler uses so called oil stop cables on some models, like on the W204. The same thing your CAT suffers from was an issue with the W203 model, the C class from 2000 on

[@sammiboii9]

Great info!!! Mercedes has had issues with their engine harness' for years! I used to work at a Mercedes dealer for years and used to replace the engine harness' plus sensors on a few models. Some models were more labor intensive than others. Dealer repair is replace engine harness, sensors, and ecu plus programming. When I would do side work on these cars and the issue was caught early enough. Replace the sensors that leaked and plug in an extension harness between the sensor and engine harness. This little sub harness was used a sacrificial piece to minimize the oil getting further into the harness. There is a 2 pin and 3pin extension harness available. Mercedes actually makes an extension harness for the Camshaft Adjuster Magnet that was used on the older m272/273 engines and can be used on the newer m276/278 engines.

[@DavesAutoCenterCenterville]

Appreciate the feedback!

[@jacquesvanzyl374]

M271 engine has same problem , installed "pigtale harness" between engine harness en camshaft magnets

[@wpcote108]

OK Dave that’s some great detective work! My question is, is there some place where this capillary action is getting a boost from negative pressure? One of the weirdest things I’ve ever heard. I really appreciate how you treat your fellow employees/workers. I’ve got a new set of C words that describes your relationship with workers: commitment, caring, compassion and cash (because everyone needs to be properly compensated for their knowledge and efforts)! keep up the great work!

[@SoBoring136]

Chances are you will not see or read this however I believe it’s important to genuinely complement a fellow human when applicable. Allowing others to see who you are has such a positive effect, you are being not doing. It inspires it encourages those of us who strive daily to be the best version of ourselves and build others up not hold power over them. You deserve every bit of personal and business success that you have worked for.

[@seanthompson8071]

People who are genuinely appreciated will always do more/better work than those who are not!

[@brandonbrucker6691]

You can thank the capillary action or affect. Surface tension of the fluid in small gaps will slowly draw itself through, something to that idea

[@ubernode54]

This

[@Conservator.]

Yep, I can’t imagine how it would have anything to do with electric current going through the wires.

[@heathjones2618]

Oil is mainly non polar minus some of the additives they put in it. Synthetic oil for sure is non polar. You have to have a charge to induce the electric effect. I agree with the capillary action theory.

[@ricksweetser1683]

Yea you do. Read my post.@@OneIssueVoter

[@zaprodk]

According to the Mercedes tech, the oil is "travelling up the current", so .... :D

[@azjohn520]

I’m an old power stroke tech, and I approve this diagnostic message. Seriously though, not the first time I’ve seen oil push through a sensor and travel up the harness, but the fact that it’s just splash oil permeating is pretty remarkable. Now for my PSA: USE FENDER COVERS!! I wouldn’t breathe near that car without blankets covering every inch of paint, chrome, or plastic molding I can see.

[@importdoc7]

42 years working on Mercedes and most all German and Swedish. 34 years on my own. Dave and his new series on the Discovery Channel will bring a lot of good light to honest and respected independent shops across the nation. Cheers to you Dave, and all the good, honest technicians out there with integrity and aptitude.

[@djrigga]

Oiling Capillary through the wiring and of a long distance surprised me that good find and diagnosis 👍

[@Trlthericklang]

It is crazy how a liquid can wick its way through a harness. Great videos boys.

[@markcavandish1295]

Right?!?!

[@stephenpoe2037]

Actually ! ! ! ! ! ! I have encountered this on two of the Fire Engines I was in charge of ! One was due to fatality oil pressure and one was a faulty coolant temperature switch ! Thanks for sharing !

[@DavesAutoCenterCenterville]

Great feedback, thank you for sharing

[@ccarlock8537]

I have also had a coolant temp sensor start to leak thru sensor, into wiring had damage wiring alo

[@JuanRodriguez-rl2ov]

Hello Dave and all you guys doing a great job! I've been a person who likes to services my cars, and I used to have a 2002 E430 and a great German mechanic once told me, "as soon as you car reaches 120k miles, change the adapter plug and filter". I never did that until the car had 180k miles when I had the experience of having ATF in the transmission computer module. I had to replace the module, clean the harness and replace the plug, along with other transmision services. The fluid traveled with "capilary" action from the bottom of the transmision to the top to where the transmision computer module is mounted... this was a blow mind lesson to me.

[@DavesAutoCenterCenterville]

Appreciate the feedback!

[@smacdiesel]

I had a 2016 s550, it was a nice car. One day a service advisor told me that a replacement engine costs over 60k, he then said just wait until the turbos go out, that will set you back about 10k. I sold it the following week!

[@TYP3RSXS]

I’ve had the same thing on a Nissan Murano. The oil pressure switch made an ECU fail. Somehow the customer got the insurance company to cover the 4.5 thousand dollar bill.

[@gavnonadoroge3092]

@TYP3RSXS how did it get to 4.5 thousand dollar bill for hundred dollar ecu

[@abemartinez7653]

I work on 18 wheelers Dave. Love the channel bud. I know for a fact Cummins isx engines and Volvo Mack have the same issues. We always offer to clean the connections, but there is NO WAY to clean the oil out of the insulation, so keep that in mind. The module hasn't failed if the car drove in and codes dont return after being cleared / test drive ect. CRC electronic contact cleaner for the module, harness if issues return and definitely any or all oil sensors with signs of oil on them.

[@samspace81]

I'm sure you guys checked the cam solenoids (magnets) too for oil intrusion. Dealt with this on my S63 AMG as well. I installed jumper harnesses between all 4 cam sensors & 4 cam magnets to help circumvent harness problems. Love your channel!

[@oakleigh4954]

Good to see your looking after the customers and great work from Dave and his fellow colleagues, great channel 🙌🏼👍🏼

[@DavesAutoCenterCenterville]

Thanks 👍

[@marcsantala8179]

Dave, I love your channel! I am a technican myself for 36 years the last 21 working for John Deere, I have seen this many times and on farm equipment I have seen this happen with water as well! One time I found a couple teaspoons of water in a controller that had wicked up the harness.

[@RGP_WA]

Dave, great team you've put together. I have never heard of oil following an electrical current! Incredible!

[@DavesAutoCenterCenterville]

Glad you enjoyed it

[@Conservator.]

I don’t think it has anything to do with electrical current. I think it must be the capillary action that lets the oil slowly creep up the wire harness.

[@bigqwertycat]

It's nothing to do with current, it's capillary action. It's common issue on early 2000s mercedes if the transmission electrical plug leaks, it goes all the way inside the passenger footwell where the TCU is located.

[@nevillegoddard4966]

@​@@bigqwertycat Yeah it's definitely capillary action but so what? That explains nothing. Does the oil become conductive? Does it cause too much current leakage where it's not supposed to go? Not that engine oil is conductive at car voltages. Or does the oil between the wires cause too much capacitance, rounding off & distorting square waveforms?

[@r.weaver3769]

I cleaned mine up, replaced the camshaft position sensors. Re-cleaned every week till no more residue in PCM, and it's been good for almost two years now. I keep an eye on all sensors that touch oil now. I did use small paint applicators to put dielectric grease at the base of PCM pins but have since cleaned it up. Wanted to see if oil was still wicking. I know the oil is still in the harness, but it had never set a code for anything either.

[@YoungAmzn]

They actually sell sacrificial pigtail harnesses they connect in between the the sensor connection and the wiring harness to catch the oil before it gets up to the worst part

[@r.weaver3769]

@@YoungAmzn No, they only make blocks for the magnet actuators for the Camshaft Adjusters, the Cam Sensors which are the only ones that leaked on my car, do not have the pigtail or block available. I thought about making a pigtail for them, but it's easier to just replace them at first sign of leakage, as getting connectors and blocks to assemble them is far more expensive. The camshaft adjuster magnets are sealed with a sealant to prevent leakage already.

[@americanpatriot2422]

Outstanding video and presentation.

[@DavesAutoCenterCenterville]

Thank you kindly!

[@uptownfragrance6148]

Where is the video follow up outcome of the work done 😮 please ​@DavesAutoCenterCenterville

[@chrisinzunza6746]

As a BMW tech of 20+ yrs, I've seen this as well at the cam sensors plus the Mechtronic connector at the trans. The Steptronic transmissions were notorious for this. Busted vacuum pumps would also introduce oil to vacuum control valves causing boost control faults. Good call on the repair. Love the channel! I would do the same.

[@coreymerritt7742]

That’s ridiculous that Mercedes would not recall such a huge problem like that great video

[@Jerryattrickliverspottedhands]

It’s common in the trucking world.

[@UnknownUser-fe5zu]

Their customer base of rich enough to pay for the repair….why do it for free when you can make money off of it?

[@coreymerritt7742]

@@Jerryattrickliverspottedhands I have sort of heard something like that on a 7.3 powerstoke but never really seen it before thanks

[@rafmatt1607]

​@@coreymerritt7742 it happens on a lot of diesels. I've seen it send oil through the injector harness on cummins 6.7 quite al few times.

[@coreymerritt7742]

@@rafmatt1607 I have an 2003 5.9 Cummins no issues also a 450 isx 2013 kenworth just a lot of electrical and def issues thanks

[@stevebigansky9372]

u guys are awesome- I've been a motorcycle racing mechanic,/rider for over 40 years and love your common sense diagnosis that is seriously lacking in the automotive and motorcycle repair industry these days - alot of "parts replacers" but not alot of true "mechanics" anymore

[@ws2664]

I agree with Kyle, I have seen that a few times on transmission electrical plug connectors.

[@timmcquerry6068]

Same here. As soon as Kyle said that I had an...Ah-Ha!

[@gordonsillars]

The ability of liquids to travel through tight spaces against gravity is called “capillarity” and is just a technical term for wicking.

[@goinwheelin]

This is why I like this channel. Keep up the good work

[@DavesAutoCenterCenterville]

Much appreciated

[@afhyoutube]

Capillary action! This is a common problem that needs to be caught and fixed before it makes its way to the ECUs.

[@jakeowens1770]

Poor wire insulation and sensors. Don't blame physics. All the other manufacturers managed to do it right except the germans

[@whyallthefuss201]

@@jakeowens1770good point. After seeing this, I went out to my 2017 GLS and checked the cam sensor connectors for any signs of oil. On top of that, I had to have the engine and transmission mounts replaced for $2,500 on the GLS with only 59k miles.

[@MontyGumby]

"common problem" with any makes ?

[@alanparks3402]

@@MontyGumby all m278 engines, m157 as well i believe, basically if you have a cls, s class, gls you should automatically start keeping an eye for oil on the wiring and connectors. Alternatively you can just install the pigtail connectors, something I would have already done but because they're cheap but I simply can't get these connectors to un connect at the cams

[@josephreisinger33]

I worked for a MB dealer 4 20 years. The things I have seen would make your head spin. That 14 S550 cost about 115 to 125k if it's not AMG. You hav2 remember that if you can afford that car, 10 to 15k repair is a drop in the bucket. But MB should good will it for FREE.

[@MontyGumby]

but the root is not fixed so will likely happen again ?

[@andysteele8267]

I am a electronics tech at a paper mill and everything around here is coated in something. Wouldn’t recommend the brake clean it might melt some of the connections or wires. Safer to use “contact cleaner”. Available at Home Depot or lowes or maybe even a good auto parts store. Good luck Keep the great videos coming

[@seanthompson8071]

Wow, great advice!

[@nevillegoddard4966]

Isopropyl alcohol (ipa) will also clean up the oil.

[@tomb375]

My New Favorite Channel! Ex. A&P Mechanic here, I love your Troubleshooting and Diagnosis. I have a 2007 Mercedes GL 450. I would love to see how to go about changing the Sub frame mounts on this truck, no info anywhere. I do know Mercedes had problems with their Subframe mounts rusting on their smaller cars but no info on their trucks. And of Course everything at Mercedes is kept Hush Hush, Super Quiet. Thanks for all your great video's keep them coming!

[@brianspangenberg9598]

Dave you have a great crew. Keep the good work.

[@seangreene64]

This also happens in Yamaha outboards starting from 2010 on any units that has the speed/ water pressure sensors installed. Causing numerous codes & erratic engine run ability.

[@andygriffith5975]

Mercedes and BMW's are wonderful cars. They give you luxury and performance all in one package, BUT. It comes at a hefty cost. I went down this very dark rabbit hole when I purchased a used 2009 BMW 335i X drive. This car was everything I could ever want. I never had a car that so refined, so comfortable and will the power and performance to match. It was very neglected when I got it. I thought I could rehabilitate it. Long story short. It completely broke my spirit and drained my Bank account, just in parts. The lesson I learned, is that if you can't afford to be in a relationship with a high maintenance model. Just be happy with the trailer park Queen 😂

[@Occuria1]

The problem is either that the owners are too stupid to use the turn signals OR they do not come with working ones from the factory...........

[@genxray951]

my motto, never own a german car out of warranty.

[@johnnywakefield7948]

Amen

[@CG-zh1td]

Or buy a Lexus . . . 😆

[@paulhoogeveen7353]

And why we don't buy BMW's.....😂😂😂

[@frankj.hoffmann7030]

This is unfortunately a quite common issue with Merc sensors (crank and cam) and happens to many engines. So you replace all of the sensors and install oil-stop cables in between the sensor and the harness. Basically, this is a cable with a cut and solder point in the middle, which you can prep yourself. Oil cannot travel beyond the solder point and so no further contamination can happen. But the harness is still full of oil up to the ECU. If time and money is not the issue, you can remove the harness and put lots of brake cleaner in it and hang it to dry. This will essentially remove all of the oil and things are back to normal. But since after installation of the oil stop cables no more oil can enter the harness a thourough cleaning of the ECU connectors would most likely do the job. But open up the ECU nevertheless to check, if oil has already entered the housing. Remove with brake cleaner. Thanks for all of your great content and greetings from the other side of the pond (Germany)!!

[@ilhommuminov708]

That’s what I thought but people making movies here 😂

[@sheerwillsurvival2064]

Your team is priceless. Experience is everything

[@glen7201]

I have seen this as well,I have a cls550 that just came in with the same issue,clean 70k car, but it will be parted out.

[@prowler2358]

Saw this alot working for cummins, mostly on M11 and N14 engine speed sensors, the pickup coils would start to walk out the end of the housing allowing oil to enter the sensor housing, it would then work its way through the harness to the engine ECU, and on into the module itself where the carbon in the oil would short out the board and fry the ECU. This is a common problem not specific to mercedes, many makes have similar issues, TD5 land rover injector harnesses are a very common one that i've come across.

[@Jerryattrickliverspottedhands]

The px9 was notorious for having the coolant level sensor pulling coolant turned to corrosion all the way to ecm. Changed a number of chassis harness for that. Detroit had a bad problem with injector harnesses pulling oil to ecm too.

[@chrisstengren8995]

I really like when you honor your employees….it’s good honest work…on the same hand those repair shops that rip off customers should be somehow publicly shamed….

[@ElvinLeadfoot]

Contamination harness.. Put it back together with the seals removed for awhile @ the ECM. Let it finish wicking the oil from the wire.. Each oil change unhook and clean the master connector several times . Tinker Love - Make some love to it:)

[@cheddarsgarage2076]

Dave I absolutely love your shop and how your guys are when diagnosing any and everything you all do!!! Keep up the great videos love em all !!

[@marilynmanson812]

I was taught about this in school. It's called different things, but I was told "wicking" is one of the industry standards. Cool find!

[@zaprodk]

According to the Mercedes tech it has something to do with the electric current, LOL.

[@marilynmanson812]

@@zaprodk I believe he is actually right. Remember electric current also induces a magnetic field. There could certainly be some reaction between the fluids atoms and the electrons. Im not qualified to explain it, but after a few years in the industry you learn anything is possible.

[@Josephdoes]

I knew about coolant migration but didnt know about oil also being able to do the same, always in hindsight does everything always make sense

[@toomuchthinkin]

Oil is supposed to be dielectric which in my mind it has to be heat related to wicking oil in the capillary sense. Thanks for sharing!!!!

[@rockyourworld5374]

Yeah Dave that is called electrocapillary action. I am guessing therefore that there will be a thermo electrocapillary action too. I first saw this phenomena on a Hyundai iload. The tech pulled the ecu, and he and i were perplex as to how the water that leaked had made its way upwards by foot or more way into ecu. I remember thinking what the heck! Now your Bro just diagnosed it. Excellent! 😊

[@zaprodk]

This is not electrocapillary action. Just normal capillary wicking. There isn't any potential in the wires across their length to have electrocapillary thing going on.

[@adventuremanintheclouds8968]

This also happens to motorcycles. The oil travels up the wires of the stator. It burns up the stator, rectifier, and sometimes even the connector.

[@GrandePunto8V]

Wait for trolls telling you that "oil is insulator" (so that's non-issue).

[@ramdozer3194]

I watch you all the way from Kentucky. I myself enjoy the hardest jobs out there. Love the way you explain and define what you are doing to folks that may not know. I prefer to work on the 6.6 Duramaxs but any medium duty diesel is right up my alley. Have learned quite a bit from your videos and look forward to watching more of them! Keep it up and this guy is gonna get a awesome engine!

[@andrewvehrs9714]

Early Nissan Pathfinders with the VQ35 had issues of the IAC Valve leaking coolant through the connector and wicking through the harness to the ECU.

[@4dscdriver]

2000-01 Maximas did it too. They use the same iacv.

[@harlemjonez4853]

Hvac tech here. Not a car mechanic but still love cars and am obsessed with your channel, Keep em coming Dave !

[@L3ggi381]

Landrover td5 enginge suffers from the same problem, where the oil will capiller up the injector wiring to the ecu. on the defender the ecu is under the drivers seat box and will start to leak oil inside the seat box.

[@fastinradfordable]

Love My 300tdi mechanical pump. Doesn’t need any wires

[@Loveitdownunder]

👍

[@matttiggerward6147]

This is similar to what happens on the Land Rover TD5s… but with them it’s through the injector wiring (which is inside the rocker cover) and it ends up in the ECU which on the defender is under the drivers seat! It’s a capillary action thing assisted by the current I think.

[@fredproctor6973]

Looking forward to the TV series.

[@coldhillgarage]

Fluid can actually travel inside the wires, quite a bit of air between the copper cardels. not a uncommon problem,,especially in boats with water ingress.

[@mrblonde2013]

The GM 3.6 has same issue, the oil pressure sensor fails, starts leaking engine oil into the harness. When oil reaches pcm, results in erratic random driveability issues. Thank you.

[@kjamison5951]

This is documented somewhere. It’s probably kept in the Mercedes equivalent of that warehouse see in Raiders of the Lost Ark.

[@xunheilvsnipezx3324]

Howdy howdy from Tucson

[@phillyphil1513]

very common on failed oil pressure sensors on Detroit Diesels, i've even seen it on pressure sensors on Motorcycles. naturally if the physical integrity of the sensor fails the pressurized oil comes right through.

[@amigo2k10]

I've seen this in an older benz but thru the transmission module

[@ftmt9568]

As an automotive technician, I can attest to the Mercedes transmission harnesses as well.

[@kevinmcauley]

Capillary effect. The stranded wire allows oil in, the oil is more attracted to the walls of the wire than it is to the other oil molecules. The oil slowly travels up the harness. We have it happen with bleach on our delivery trucks.

[@clinttrigg1512]

My cls 550 did the same thing .

[@leew8307]

What did you do to fix it?

[@Saykes1994]

5:16 This happened due to the capillary phenomenon, diesel fuel on Hyundai, BMW, Renault, falls to ECU, the same phenomenon in your case.

[@ericsbr]

I remember back in the early 80s a gm car came in with coolant leaking on the carpet from behind the dash. Must be a bad heater core right? Ha, turned out coolant temp sensor leaked and sent coolant up thru the wire into the PCM which was located behind the dash. Coolant was literally dripping out of the PCM. 😂

[@sheerwillsurvival2064]

Old GM tech here seen it to 👍🏻👊🏻

[@Keith-m8b]

Hi Dave we have the exact same problem on the old type Landrover defender the engine is called a td5 it was the first 5 cylinder diesel engine to be fitted in the defender the oil travels from the injector harness straight to the ecu we fix it by changing the injector harness and brake cleaner the ecu the majority of the time this works cheers from the UK

[@totalyep]

A Mercedes leaking oil? Impossible.

[@ericb8030]

This is common on International dt466s. Have to keep an eye on oil pressure sensor and icp sensors or the ecm connectors will end up being full of oil

[@rafaelalvarado4764]

That crazy this car oil in harness

[@jacksg5430]

Mercedes tech right here, he's 100% correct!, i had one that the oil travel all the way to the ignition coils as well as the ecu

[@kevinlewis1235]

Most expensive parts I’ve ever installed. Aftermarket alternator was $500. The guy at the store was shocked. I told him it’s $1500 at the dealer.

[@jondiaz3475]

Porsche says "hold our beer"

[@bmarklar]

Try a v12 s600 water cooled.

[@bmarklar]

Wow I went to rock auto to check. Proces came down a bunch Back in 06 I helped a friend replace his alt on a s600.... that alt was 2k

[@jumpinjojo]

I bought a used alternator for my C300. It was $100. Good enough!!

[@wolfm3388]

From many companys you can buy sensors aftermarket to prevent it from happening again! MOTOREN ZIMMER IN GERMANY MAKING A SET FOR THAT CAR!!

[@billy4072]

Capillary attraction. Cable tie it

[@0num4]

Thanks Dave & co.! Now every time I'm under my hood, I'm going to be looking for oily connectors...just in case. It's an easy thing to check (don't necessarily need to check *all* of them) while you're already in the area.

[@Bruce_Wesley]

Very common issue on the m157/ m278 engines.

[@simonm1447]

It was also an issue on the M271 engines of the first generation. The 2nd gen from 2007 on got so called oil stop cables to prevent that. Sad they obviously not use them on other engines too. This is an old and well known problem which even happened on the Boeing 707 with cables going into the fuel tanks

[@donniebagwell9536]

I am a DC power technician and I absolutely see this happening good call

[@stevecoleman4352]

I know how to solve that oil travel up through wires 8:07

[@stevecoleman4352]

As it comes out the motor the wire clip that’s there cut all the wires put another harness to them that has Vaseline between them and replug back in

[@stevecoleman4352]

😊

[@alihenderson1362]

I love the condition, cause, correction, confirm that’s awesome!!!!

[@totalyep]

It’s not from the current guys. Its capillary action.

[@stuartschwartz982]

Likely! ?Thge smaller the "pore" between the wires in the harness, the greater the capillary tension. If the harness is running horizontally, there is minimal gravity force limiting the capillary distance travelled.

[@jlazaro90]

Hello from the state of California. I love watching your videos. Full and short videos. Please keep them coming. I always look forward to the next video. I was introduced to working on cars since I was 8 by my dad and never stopped working on my own and friends' cars. Wish I was employed by a shop like yours. Great job on the channel.

[@pbysome]

God stop interrupting him man, you ask for him to give an expert statement then talk over him, rude and not bright.

[@LovelessAndroid]

100%!!!

[@carlosurquijo7819]

Yes super common. The cam magents sometimes leak as well or the oil level sensor in the front of the engine. Sometimes the oil will go to the O2 sensors as well

[@mikemata623]

BMW tech here, we see this a lot with the N63 engine. Not oil but coolant will go thru connecting terminal for the thermostat and work its way into the Bank 1 DME and fry it. TSB is available for this issue.

[@nickanagnostou5408]

M278 motors and others do this. common problem. sounds crazy but true.

[@eduardoyepez7358]

04 pt cruiser… found that out a few years ago… it really stumped me that day. Pulled it right up to the PCM

[@joodmkaddem7151]

I think its the positive case pressure From Syria I'm a big fan guys

[@chrispassarella5634]

Happens to alot of chrysler vehicles as well the oil wicks through the harness to the ecu I had a town and country that the ecu had oil pouring out of it from the cam sensor

[@SPMech1]

I saw that on the 2 liter chevy engines in the Cavaliers in the 90's. Oil pressure sensors allowed oil into the harness

[@normanmallory2055]

That’s unbelievable! Wild , I’ve never seen that in any shop before !

[@MrMotorNerd]

Capillary action is whats its called guys . Wicking is a slang term . Love ya work

[@brokenujoints3811]

Great video, especially the blessing! Ive seen this on a 2006 Yamaha Apex snowmobile, oil in the connector to the ecu. Apparently travels through the harness!

[@daxkindle5154]

I soo wish you were in my area! I have a 2012 Mercedes-Benz cls550 4matic and it's hard to find many honest reliable mechanics that won't break the bank; great shop great mechanics great owner!

[@100mileseverythingLLC]

Great information I've been working on mercedes for over 16years shits still amazes me. Don't forget to look at the tcm the transmission fluid tends to do the same to that as well.

[@DavesAutoCenterCenterville]

Appreciate the experienced feedback!

[@100mileseverythingLLC]

@DavesAutoCenterCenterville Appreciate the great content guys such a great Show to watch. This is what the people need. 👌🙏🏽

[@Borkery]

i believe the oil will wick up the wire within the sheathing, just like its supposed to do, it penetrates and wicks up the metal, wicking its way down the wire and any metal it can find. the flow of electricity over the wire may effect it but im unsure about that part. what a crazy thing to see. Also the last year you could get a good Mercedes was 1992, they started getting to sensor filled after that.