Those are cam solenoids. The cam sensors are just above those on the valve cover near the oil filler cap. The cam sensors (not the solenoids) are the problem. Need to also check the 2 large connectors at the ME. BTW I’ve been working at the dealer for 24 years. I know what I’m taking about.

🤣🤣you told a Mercedes that it wasn't gonna make any content for us during the first video that Mercedes said hold on a minute ill show you

It's easy to fix. You just need to braze two new cable. Cut off the plug (with 20cm of the cables !) and from this piece you cut of 15cm that 5cm will left at the plug. Flush that with electric cleaner! Bath it for 5 hours in it. The other 15cm you replace with new cables. Braze it together, done! Greetings from Germany

You know it's a great vehicle when the previous owner spent the money they did on it. Then they sold it just when some extra money and work would have finished the job. Now you get to carry it on and finish it for half what the cars value is and the enjoyment is priceless. The best part is we get to follow along with you on the journey. Thank you. Another great video.

As an electronics tech, I'm not sure what the oil is doing to the wiring. Oil is non conductive. You can run the whole wiring loom in a bath of oil and it would be fine. As long as the connector surfaces are clean, your problem doesn't sound like oil issues. Check continuity of wiring back to the DME. If OK, it's an ECU problem

You should be able to cut that particular section of the harness back a see how far the oil intrusion is and then solder a new wire harness with a new connector and that should prevent you from having to replace the entire harness.

You definitely 💯 % don’t have to replace the engine harness. You run a new wire from the sensor to the computer.

Hey Randy, just to let you know. I own two cars with M278, right after this vid I went and inspect the plugs for all those sensors. 2 out of 12 had oil in them, although I have no codes and they both run fine. Ordered new sensors - super cheap from MB and will be doing preventive maintenance thanks to this vid. Big Thanks!

I didn't see you use a multimeter and or test light to see if you are getting reference voltage, ground, and ohms from the electrical connector going to the intake camshaft sensor. With either key on engine off or engine on. The wires might be chaffed internally, one of the pins on the connector may have backed out. If it's not the sensor it's the wiring. All you have to do is order a pigtail wiring kit with the connector and splice it into the existing sensor wiring. You don't have to buy an entire harness! From; George and Dad Decker "Fcp sells a kit that includes sensors, hardware, and sacrificial harnesses to fix this. They also sell cam sensor kits, timing chain kits, and off kits."

Had same issue with my 2015 S550. My mechanic knew exactly what it was fixed it in about an hour. Like you I thought it was a catastrophic issue. He said this usually happens around a 100k miles. Undoubtedly previous owner went straight to the timing chain and overlooked the simple fix first. Hopefully your wirin harness is salvagable. Great content as always

Congratulations 🎊 Randy. The Mercedes is a keeper.

My Mama done told me.....Never fall in love with a car, because it'll cheat on ya with your wallet 😄

I watched one of your CAR videos and all of a sudden you turned into an HVAC mechanic, and now you are a Mercedes mechanic, AMAZING!!

I gotta say, your a better Merc technician than you give yourself credit for, props for you , good job I'm impressed 👍

Now that was fun to watch you diagnose and attack the problem.

Im a Mercedes technician. You are on the right path. The cam sensors on the top of the valve covers is what normally seeps oil into the harness. If it isn't caught in time it will continue to travel all the way to the engine computer (ME) if cleaning the connectors at the sensors and solenoids and also at the computer side with the addition of the pigtails does not solve the problem. Worst case you will need to replace the harness. The good news is you absolutely do not have to pull the enegine to replace the harness. Ive done the harness in the car. I would just recommend using a lift for the job. Hope u get it sorted out. By the way, yes the M278 engine is a very reliable engine.

Damn! That sucks Randy. Fingers crossed that the fixes you are going to do solves the problem. It is such a beautiful car. Great video!

I am a technician at mercedes and those engines can run on various types of oil.. we always use 5w40 on these but other approved viscosities are also applicable, those engines can take a punch tho

Try to use osciloscope (you computer might be able to do that) to compare compare signals, try to connect ecu and sensor with direct jump wire (you can fix small holes in wire insulation with with liquid tape)

Fun, fun, fun. You tackled a tough job! These newer cars/trucks force you to go to the dealerships. I'm proud of ya man!!

Fcp sells a kit that includes sensors, hardware, and sacrificial harnesses to fix this. They also sell cam sensor kits, timing chain kits, and off kits.

I´m learning how to deal with this problem NOW, before I get the car!!!!!!!!!!!!Thanks to you. I can have confidence .

Those S550 are beautiful - from a distance. lol Also I did not know oil will damage wiring. If you open up the transmission - there are exposed wiring and connectors right in the belly of transmission - swimming in transmission oil.

A lot of people think that Ow oil is way too thin. 0w oil flows the fastest and a lot of these newer engines has very very small passing holes to get to the timing components. If you use 5w oil it doesn’t flow as fast and it can actually get a little restricted in the holes causing big big problems.

Thank you for sharing your step by step diagnosis. Great video and I enjoy watching it from front to end. M378 is a great engine but has this week point of camshaft sensors and magnets.

You leave that tornado hatch open. I’d be afraid of falling in it

Great content. Randy got me thinking about getting a S550. Started looking at some online. But I just don't have what it takes. I'll keep rocking in my 1983 Turbo Diesel Coupe. Keeping that thing running requires the knowledge of a good lawnmower mechanic. Old lawnmower. . . not one of those new fangled one.

Great video sorry to hear that. Looking forward to see them follow up videoes of the repair. 👍

Disconnect the battery, remove DME, clean the pins on the module itself and the sockets with cleaner and compressed air. Hopefully it would help. I had similar issues before and it worked out well. Good luck!!!

Man if it was me I’d repin thee connector and splice in new wire rather than pay for a new harness I mean it couldn’t hurt it to attempt an old school fix like that but the extensions

Good Video Randy Good To See You Working On A Car I Always Love Watching The Variety Of Videos On Your Channel

I also agree that criteria of a bulletproof and reliable Twin turbo V8 Engine car are: 1. Timing issues requiring harness replacement; 2. Plastic oil pans, which are more durable and reliable over time compared to steel or alloy ones, because plastic is better for hot oil carrying the heat from the cylinder and turbos.

Great diagnostic work and good explanation for trouble shooting the problem

Randy like I said next time buy a Lincoln Town car! I know they're not quite as fancy as a Mercedes but they sure are comfortable and they have good power probably not as much as a twin-turbo Mercedes God knows but how often are you going to be flooring the damn thing going 150 miles an hour in Oklahoma not too often.

People need to realize that no matter how cheap they buy a car like that. They are still maintaining a six figure vehicle. It doesn't take long for parts to get very expensive. Unless you dont mind driving a car with warning light illuminated on the dash. Beautiful car tho. Thats for sure!

Use that electronic cleaner really well and then use dielectric grease inside the actual plug on both sides. That grease has helped me fix multiple electronic issues. I would try it after replacing the sensors

I really enjoyed this video. Its been a while that I can go on youtube watch someone trouble shoot to fix their cars and find solution and resources. I cant express how cool it was to watch this video. Great content

Great, great content. I'm building my car chanell & learnt a lot from this. I love this version of the S Class. Now this is what mechanics/dealerships dont do anymore ..common sense and patient diagnostics to solve the issue

This was a captivating video. Well produced my friend.

Such a fabolous looking car Randy! Hope everything goes well

Thanks for the video, Randy.

This is brilliant and helpfull, as I am thinking of getting one of these in the next couple of months, thanks a lot for doing this video, really helpful!

I am new to your channel but trust me I am just in love with what you do. I am a proud owner of an SClass. I enjoy following just in case I encounter something similar. Can’t wait to see the next video.

Nice video. I call this light the money light. It makes you spend money. The mercedes motor is nearly indestructible. But the sensors are underdeveloped. The guy who invented this light is a god for car industry. Don't worry. Nothing will happen. And damn, u made an incredible deal with this car 😮

Great content, I would definitely go ahead & prevent, looking forward to next video.

Randy, this is like an old skool vlog from you. I miss you fixing cars up on your driveway or yard.

Your MOST enjoyable video in a long time. Sorry, not into your junk yard tours. Can't wait to see more on this car or mechanical stuff. With content like this I will subscribe again .

Thank you for your time and effort.

The coolant return pipe here in SA some of us call it a Quarter to 5 ( 16:45) pipe... Mostly it breaks when you're putting everything back together around 16:30 when you're looking forward to start the car and call it a day 😂😂😂😂

had this on my 2011 ML, and it was the cam sensors and front and back. $2300 dollars later and 4 days. They fixed it. and yes they replaced all the sensors.

I do hope you get it sorted. I agree with you about the experience of driving such a car……..

I think you made good progress with it Randy, good luck with the rest. 😎👌👍

Keep going Randy good content.

Awesome channel and love your content and also i been looking into getting a S550 for the first time. I had a BMW IL 740 and it was nice.

Will keep my fingers crossed for you. Good luck!

Love all Benz videos looking fwd to next update on s550

Burger King custodian engineer here. I know that comet cleanser with bleach cleans almost anything.

You did exactly what i did on my ml550 with the same engine. I changed all my magnets and the cam sensors. And i too broke off that hose. And I temporary repaired it the same you did. What a coincidence...

that car is wonderful Randy no matter what. I love it and your at your new house also which I love. beautiful property.

this scanner works nicely, thanks for sharing

That S-Class is CLEAN!! I bet it rides smooth like a charm too

Thanks for all the info you put on your videos I was thinking about buying one these Mercedes I like the car and im not afraid of the high miles. I know what to look for when I start looking for one these cars thanks again.

Mercedes Benz tech here . The 270,276,and 278 engines are prone to the camshaft sensor pickup rings spinning on the camshaft . Something to be aware of , the same exact thing will occur . You may need an intake camshaft

Can we get the Mercedes badge for the beauty cover under the hood. My OCD is kicking in!!!! Another great video Randy thanks

Just wondering what is going on in Terre Haute, Indiana? Haven’t heard or seen anything lately.

Just went through this with our c180 w204. Cam censors replaced and harness cleaned with that done. It would shut down sometime and would start right back up or not. Had to replace the electronic start /stop key module. Problem solved. Check engine light still occasionally comes on from time to time from the oil intrusion into harness issues

Randy I love it when you REDLINE your cars just to see if the engine is any good!! Could you do that more????

You have the patience of a saint, I admire your tenacity

What a great informative vid ! Thanks !

Really good video Randy, I want to see how it turns out, in my heart I wants a S550 or CL550, but my brain/wallet says stick with the Hyundai Equus for the moment I was considering the S550 or CL550 but I got a 2014 Hyundai Equus instead as I had 5 MB's, and I needed to get away from the repair bills. The air suspension on my Equus leaked but I converted it to coil over from Strutmasters, and I love it!!, the check engine light stays on because I didn't wire in the Strutmasters unit to put out the Warning Light (I previously stated it was the Check Engine light, but its a Warning Light as the ECU is trying to find the Compressor and Struts) because that would have switched off the Sport mode which altered shift points, which I wanted to keep. The result was that a Warning Light (Yellow Triangle with exclamation mark inside it) stays on all the time, so I put a small piece of black electrical tape over the dash, result is no light and nobody notices that the tape or check engine light is on. I also took out the Compressor Relay to stop the Compressor running.

Hi there, I have a few Mercedes-Benz's & also considered myself a car guy so I enjoyed watching your video. You're well-spoken & very knowledgeable when it comes to troubleshooting. My question to you here is why you opted to replace all 8 sensors when the scanner only pointed to 1 as a potential root cause? Also, oil isn't very conductive & each individual wire is insulated with thermoplastic/telflon material so even if some of the oil has made its way inside the harness, I don't think it'll cause the harness to go bad (intermittent and/or shorted out). That's my 2cents. Best of luck w/ your troubleshooting & hope you'll find the root cause soon.

Thank you for a good video and keep up the good work bud

My trailblazer used to do the same thing! I would clean up the wire harness and replace the camshaft position sensor every xxxx amount of miles lol

19:35 Randy that is the correct oil to run however the dealer likes to put 5w-40 because it can be bought in bulk.. at least where I live

Get a hold of Alex over it legit street cars that man knows these cars and has rebuilt these motors on his channel he is very very knowledgeable and I'm sure you already know

Hey randy! Great video as always and very entertaining. Just wondering when you mentioned working out in the heat sucked - i was thinking about when you used to talk about the shade tree at your uncles house. That got me thinking, will you and mike be visiting your uncles house in the near future for an update? Keep up the great work! Leo in UK

I’m surprised you are so into that car tho. O well great video as always still lovin the channel one of the best out there

Great job .and enjoying good man keep on .

Hope you can fix it man and bring the car to a better state. Anyways good work Randy 👍

Dang I’ve tossed around the idea of buying one before but they scare me to death lol. Beautiful cars though

I had to rebuild this M278 engine and had same code and it was the camshaft. these cams has laser marks and you have to be carefully when tighten them. I don't recommend changing wires or messing with DME because it will be waste of time.

Very scary watching such an expensive luxury car leaking oil into the sensors. I believe you will eventually get to the bottom of the problem, hopefully the cost for solving whatever the problem is, is not gonna be outrageous. Thank you for the video it's very informing.

This video was great to watch. In the first video you said it wasn’t going to produce content. The Benz said hold my beer 🍺 😂

great video ,you are A very patient man.

Hello Randy. Let's see what's wrong with the Mercedes S550. Hopefully it's not too terribly bad.

I had to replace the intake camshaft and replace the cam adjuster. I had already replaced the cam sensors and solenoids as they have an oil leak issue. New parts are updated so hoping that problem doesn’t comes back. The camshaft position disc spins off by a few degrees. The new camshaft has an updated part number. If you hear clicking sound coming on a warm start it’s related to the cam adjuster failing. This vibration probably spins the position disc off. I had the same engine light on occasionally.

I really like this Benz! Hopefully it’s an easy fix Randy!! Fingers crossed it doesn’t come back! Bummer Randy!

Fantastic video

I’m 90% sure my next car will be a S Class, this motivated me to ale sure I get one Certified pre owned with warranty. 💯

Great video.

Randy this car is so good it just has to be fixed John says that they are bullet proof. Keep your chin up it's worth the bet.Alan Northern Ireland

Good luck on your car i myself have been there many times but you just got to keep going and after you fix it you will know the working of a M Benz for next time

19:45 damn right lol. Bought a bmw for really cheap because it was throwing timing codes. A simple oil change cleared every code and it's been running great for the past year

Good luck with this project

Randy,my fingers are crossed. I hope you can fix it. That's a nice car. If u fix that minor problem that car is going to last u a life time. Is worth the fix. Randy have a nice weekend 🎉

I mean, I’m predicting it’s not a major issue or anything serious because like you said the camshaft had anything off, it would not be running, nearly as smooth😂 CLEARLY

It was fun to watch you take that car apart and fix it.

My engine light has been on for 230k miles. It has a total of 243k miles on it. Runs like the day I bought it. Its a 6 cyl 2.5 24 v Duratec in a Merc Cougar.

Man, I hope it's an easy fix. It's such a nice car to suffer from an issue so trivial as a leaking sensor.