C250 Sport - No oil change in 6 years and 50K miles.
 

My 2013 C250 Sport finally gave up after being driven for 50K miles without an oil change or any other maintenance. The cylinder head gasket blew and coolant leaked into oil making it milky and white smoke out of exhaust. Quotes to replace the gasket were pretty high so I decided to do the repairs myself. This is what I saw when i took valve cover off.


https://cimg6.ibsrv.net/gimg/www.mbw...184d82cb13.jpg
valve cover
https://cimg9.ibsrv.net/gimg/www.mbw...1c12850aae.jpg

Your C250? Why would you willingly do this?

Wow ....

So, you want to repair this but won't do an oil change...

Testing the absolute reliability in a hardest way...

I did not set out to do this but life happened. In the back of mind I always knew i needed to do basic maintenance but I kept procrastinating and the Car kept running good without any issues or CEL lights so it just was not a priority.

I guess this is the one silver lining of the situation, I know now how long the m271.8 will go before breaking.

Geeeze... like neglecting a child..

Crazy comes to mind.

Oil change takes 30 mins at dealership...

That's way beyond procrastination! Good luck

The scary part is what does all the oil galleries look like through the rest of the block etc.

Good thing is you can tackle it yourself and it gives a good insight and lesson for others who procrastinate on oil changes.

The tear down continues. Not as bad as i expected.

https://cimg2.ibsrv.net/gimg/www.mbw...e6271e5dfe.jpg

https://cimg3.ibsrv.net/gimg/www.mbw...eaf521970c.jpg

https://cimg4.ibsrv.net/gimg/www.mbw...1c831bde4e.jpg

https://cimg5.ibsrv.net/gimg/www.mbw...c5f748fa39.jpg

https://cimg6.ibsrv.net/gimg/www.mbw...0bb3c1a609.jpg

https://cimg7.ibsrv.net/gimg/www.mbw...0ca6db40fc.jpg

https://cimg8.ibsrv.net/gimg/www.mbw...a5c5a80627.jpg

Thanks for reminding me. Mine is at 49K since my last oil change..............I love this forum! Probably just saved me $7K from having to buy a new engine.

Actually, I don't know what to say. Could this be an early April Fools Day post? If not, I do give the OP credit for even owning up to this. You had to have had some symptom something wasn't quite right. I see your first post was a week ago after being a member over eight years.

There wasn't any signs or symptoms until it started blowing white smoke. There wasn't any over heating, no noticeable coolant loss, No rough idle, No low oil or coolant light. The only light that ever came on was service due which i promptly reset. I joined this site when I owned my previous W203. Never had to post anything as I really never had any issues with either car until now.

I was literally going to find out where you live, drive over there, and slap a bunch of mobil-1 0w-40 all over your car.

If it had Mobil 1 it might have lasted another 5K miles.

I wonder what condition the tires are in.

Meh, who has time for that? Just run 'em until one of 'em blows, then you know it's time for new tires.

How often did you have to add oil?

Three or 4 times in the last year. A total of 8 to 10 quarts of 0w40.

There should be at least one driver from each brand and each engine type to run this test in the same way, to find out which engine lasts the longest without any maintenance.

Out of all the engine types, the DOHC 4 cyl is one that requires consistent oil changes due to the amount of work they have to do.

Also, you must have driven the crap out of it to have it fall so early.

Your wasting you time OP, engine is shot. Your better off buying a used one and putting that in. U Might want to work on your procrastination, that’s beyond extreme. Sorry.

We will see what happens. Engine was running fine except for the white smoke when I took it apart. It will be running when I put it back together and if it doesn't I will decide what to do when I get to that point. Right now am cleaning the block, the pistons, head, cams , rockers and cam housing. I also plan to drop the oil pan and clean that out. I will then start the rebuild and will say what happens.

One thing I know is I don't listen to naysayers.

I’m not trying to put u down on your effort, but i’d Give it a 10% chance it’ll work well with just cleaning it. Chances are strong the cylinder head is warped, camshafts are scored, all the bearings are almost definitely shot, piston rings will be shot, your crankshaft is probably scored, cylinder walls ( the 2 I saw) are in terrible shape. There are also many other things going against you and details on those problems but I think this explains some of the logic behind my statement. Do you have the service manual? Everything has to be specifically torqued. With the amount of work you need to do for an uncertain result it’s best to buy a used engine.

Ok thanks for clarifying I misunderstood your previous post.

I checked the cylinder head for flatness and it appears to be flat. I also checked the block and it also appears flat. I did a leakby test before taking engine apart and found no issues there. As to the crankshaft and bearings I dont know. Yes I have copy of the WIS and I know all the torques and torque patterns.
I am going to give it a go and if it doesn't run then I will decide whether to buy used engine and drop that in, The problem there is no telling if that engine was abused like this one.

When we we talk about engine tolerances we’re talking measurements down to a thousands of an inch. The head may appear flat but I bet you it isn’t, the block probably is though, not too common for a block to warp. You mean a leak down test? What was the %? You need new head bolts among other hardware to re-assemble it. I’m not saying you won’t be able to get it to run, but at the end of the day the engine will become a constant problem and need replacement. The fact that you put 8-10qts of oil in the engine in the last year tells me you have significant internal issues, and will burn a lot of oil running. German cars are a lot more precise then Asian/American cars and as a result require more attention with maintenance. Used engines usually come with 1-2yrs warranty from salvage yards so you are reasonably safe, if you are paranoid, get the vin of the car and have the dealer look it up for maintenance, most people bring a Benz to the dealer to maintain and a dealer can see that record.