Just got my hands on quite the project. 2014 Mercedes c250 with the 1.8L, This car went over 31,000 miles with no oil change. Dont ask me how, Beyond me. Lifting the oil cap its fulll of sludge. the car overall has 90,000 miles and it starts and runs fine but starting it up it makes a SERIOUS cloud of white smoke, Straight from a bond movie. also check engine light is on with a variety of missfire codes of course. My question is what to do with this car. Open up the engine and try to remove the sludge? is that even an option? change the 30k oil perhaps? or just cut to the chase and get this thing a new engine. Any advice is appreciated!

 

Hello Kbod,

I've recently purchased a Mercedes C200 Kompressor (2008 model). Bought it for 2,000 USD and the seller thought the car was done for... Fortunately for me, the car was amazing after fixing. My point is, don't give up on the car unless it gives up on you.

Change the oil, get seals checked, make sure there are no leaks, clean off the engine and make sure everything is spot on.
Change the Spark plugs as they've been running on sludgy oil.

Check those things out and get back to me.

Best of regards,

 

Sounds like a cylinder head gasket to me!!
Depends on how long it's been driven with the oil in that state..

 

This is what you have to look forward to:

https://mbworld.org/forums/c-class-w...50k-miles.html

Good luck! I hope you have fun and this project wasn’t/isn’t costly.

 

Is there any guide on getting the engine into timing mode and getting it down to the bare block and pistons? Ive done similar jobs in N26 Bmw, But on that car FCP euro did a guide which makes a huge difference.

 

I would first change the oil to remove the sludge that's in there now. I would use synthetic oil as that's what all MBs leave the factory with and it might be what's in there now. Finding oil in your coolant would be another indication that the head gasket is bad. After you've changed the oil, I would also run a dose of engine dye and see if that can help you identify any additional oil leaks that might help to explain the white smoke. I also agree that the spark plugs are likely toast as well. Their condition can also help to further diagnose the white smoke. It's a shame when a nice car gets abused like this. I also wouldn't give up on it just yet. Since the oil hadn't been changed in 30,000 miles, it's likely none of the other fluids have been changed either. I would suggest that you change all of the fluids so that you can start fresh and get back on a regular fluid changing schedule. Glad you're making the attempt to salvage this W204.

 

I thought it has a good chance of being a head-gasket as well, but upon starting the car the air heavily smells of burnt oil, and the car quite literally makes a cloud of smoke that lingers for a minute or so, also when parking it missfires and idles extremely rough, Ill look into the coolant and change the oil to see if there is intermix, And I do plan on replacing spark plugs along with taking off the valve cover and oil pan to clean them out, Ill check on it later today and report on my findings.

 

There is a known issue with timing chains and sprocket wear on these M271 engines.
If it is badly worn the chain will jump a tooth or two so the timing will be out and there is risk of bending valves.
I would focus my initial efforts there before wasting time doing simple things like spark plugs.
Pull the cam cover and check the timing.

 

And check the condition of the camshaft gear wheels.
The timing chain has a tendency to elongate and to wear off the gear wheel teeth —> the timing chain will jump and wreck the engine.

 

Ok! I just got back from looking through the engine, I removed the coolant cap and honestly... no visible intermix It was all blue and full to its level and neither the oil nor coolant cap have milkshake on them. I see not much indicating a head gasket failure, im pretty sure that massive cloud of smoke coming from the car is oil smoke. next I dont think the car jumped timing, it runs really really smooth.... just massive smoke.... odd right? I do notice that with the steering cranked and in reverse the engine has a BAD missfire. as for codes in the DME its just missfire codes along with a reduced output code. This weekend I plan on dropping the oil pan and valve cover gasket and using an assortment of brushes and cleaners to remove as much sludge as I can, Ill also do a visual inspection along with spark plugs. Ill then put it back together and fill it with fresh castrol 0w-40 oil with some marvels mystery oil, does that sound like a good idea?

 

I would like to think one must vacuum, so nothing goes through, in or down.

 

Once you get the sludge cleaned out, In addition to checking the condition of the spark plugs, I would also run some engine dye to see if there are any leaks. I also have a hunch that oil is getting by somewhere and that's why you've got smoke out your tail pipes. Using the engine dye will help you to locate the leak. Make sure your coolant is MB coolant. I've read too many destroyed cooling system horror stories written by people who didn't use MB coolant. MBs are not compatible with non MB coolant. Never heard of marvels mystery oil. Just stick with the synthetic.

 

He did mention a big cloud of white smoke.
That sounds more like coolant being combusted as oil would produce blueish smoke.

 

alright, just changed all 4 spark plugs and did a full oil change and filter replacement... wow the oil that came out looked like crap and the filter was basically non existent. New filter and fresh oil put in and I took it on a test drive... didn’t end well, car billowed smoke like CRAZY and it was a bluish white smoke, smelled HEAVILY like burnt oil, and no I checked the car for leaks and not a single drip of oil coming out the engine onto the under-tray. On the drive The car wouldn’t accelerate at all really and after stopping at a red light taking off was hard as the computer restricted the engine and it wouldn’t even move past 4 mph till I really persuaded it...from inside it ran perfect but from the outside it sounded like an old muscle car and was very camshaft noise knocky, after driving 1 mile my brand new oil already looked black. I don’t know how savable this engine is but I’ll continue to try and run it in hopes of the new oil cleaning up the car.

 

This would be interesting, examine the new filter.

 

I am 99% sure your valve stem seals are leaking. Also your lifters are likely blocked or restricted.

 

my exact thoughts. The running rate for a new engine parts alone is there about 3500$. While I can tear apart this engine and attempt to save it I’m trying to see if that’s reasonable considering the labor involved and the fact that no matter what this engine will never be the same. I can only imagine the vvt solenoids and cams all clogged up with sludge and even in the off chance I save it with a rebuild the fact it was so absused leaves the accelerated wear on the metal parts questionable, so what seems to be my best corse of action, try n save this engine or order a new complete assembly from a wrecked car?

 

I had to make the same decision at the beginning of 2019 and I decided to try and save the engine - that had gone a little bit over 50K miles without an oil change. It took me about a month and a half to complete the job from start to finish - working on it in my spare time never longer than 2 or 3 hours a week. The job was pretty straight forward if you are somewhat mechanically inclined. The total cost was something like $1500 parts/tools as I was able to clean and reuse almost all the original parts. Its been 10.5K miles since the repair and the car has been running flawlessly - so i can say I succeeded.

The simplest solution would have been to buy a used engine from a wrecking yard and put that in but I figured since it was already "broken" I might as well give it a shot as I could not make it worse.

What I would tell you is do the tear down to block, inspect all the parts for wear and tear, warpage, scoring and the like. By the time you get to the pistons you should know whether it is worth your time and money attempting the rebuild.

My rule of thumb was since it was running before i started the teardown then it has to run after I rebuild it as long as I do everything correctly.

 

What did your spark plugs look like? That can be a clue. At this point, I also don't think it would hurt to tare down your engine to see what you're dealing with as there are risks to getting an engine from a junk yard that might wind up not being in much better shape than what you already have.

 

I remember that post of yours. At first I was like “why?!” but by the end I was rooting for you. BTW do you now change your oil on time?

 

Ok so the absolute weirdest thing just happened, I start the car this morning and it still smokes and runs like crap and it would barely even idle but I kept driving it and driving it and driving it and after a little it would actually move a little, so I floored it and just absolutely kept the rpm as high as I can... and it stopped smoking... I haven’t done another cold start since but upon driving the car hard it didn’t smoke at all and If it did very little compared
to it’s past, it still has a bad misfire at low and medium rpms but it goes at high rpm... with no smoke, and just as I was about to go home and park the car the brakes failed, I have no idea what is wrong but the pedal is rock solid and takes both feet pushing as hard as I can just to stop the thing... weird huh.... anyways I’ll look into the failed brakes but I’m thinking of going back out today and driving it more and then draining the oil and filter. And repeating my “scientific” process

 

Would an airleak cause it to misbehave at lower revs but not count at high revs, open throttle less vacuum-?

 

possible? After all I was told prior to giving up the previous owner had an entire intake manifold replaced my the mercedes dealer. Im just curious as to if there was a vacuum leak Why the Engine light is only throwing out multiple cylinder misfire codes. Im going to open up the hood and see if I find any obvious air leaks. I want to take it out on another drive to see how much more I can clean that oil but honestly im gonna need brakes first, and right now the pedal has 0 assist.

 

The brake assist vacuum pump is driven by the exhaust cam. If that pump failed due to the lack of oil, you can get brake failure like you described

 

Hi, I am not sure how complicated a vacuum leak can get on this engine, like anyplace from where the piston can draw suction going down, if its below the closing of the valves, theres probably a blow by out somewhere going to be-?