Cholleman

I changed the oil in my wife's car yesterday after she got a message that said add oil (8K on current oil so I decided to change rather than just add). While I was under there, I noticed some oil on the bottom of the oil pan. I inspected the drain plug which looked fine and didn't appear to leak. So looking higher up the engine from under the car, I noticed from the passenger side there appears to be a small leak from somewhere up around the rear of the engine. Is there maybe something common that you guys have run into before that leaks from this area? You can't see it from the top of the engine and the leak is slow enough that there aren't any spots in the driveway. Any thoughts?

LILBENZ230

My car, also an 05 C230K, had an oil leak from an improperly installed oil filter o-ring. I think the oil filter is on the driver's side top of the engine, though. Just a thought.

Cholleman

really? the oil change before was done at the stealership where we bought the car from since it was free, and freezing during the winter. i didn't see any oil around the filter housing area but it was a little hard to tell. can you elaborate on the o-ring that was installed improperly? the bottom two o-rings i'm sure are correct, but the top one could go in two potential locations. i installed the new one where the old one was. short of a head gasket leak (not likely i'd imagine. car runs fine, no white smoke and no sign of coolant in the oil during the change yesterday) or a valve cover leak, i'm not sure what else is up there that could leak.

LILBENZ230

Well I wish I had more details! But the car was at the local Mercedes dealership for an unrelated issue. The tech was driving it to diagnose something and it prompted him to add a quart of oil. They investigated and found that oil had been running out from the oil filter, down the back of the engine but it wasn't making it to the ground. They reinstalled the filter for free and topped the oil. A Nissan dealership in my town does the oil changes and they cleaned up the mess. But you couldn't see any oil underneath it, and there was no oil visible under the hood.

I never actually got to see the process and all it says on my paperwork is "improperly installed oil filter o-ring caused oil leak"

It can't hurt to take it apart, verify it is installed correctly, and then clean up the oil and drive it. If the leak returns you'll know you have a problem somewhere else. How many miles do you have again?

EDIT: Or it could be that during the oil change last time, when the filter was being changed, some oil dripped out. Depending on how much we were talking about, and whether or not it seemed to have been there a while. Again, just a thought. Hrm.

Cholleman

thanks. after reading your post, i searched for some pics of the correct position for the orings. it seems that my large oring is in a different groove than what i've seen in the pictures. as you can see in this pic, the o ring is in the groove closest to the threads.



mine is in the groove closet to the cap (just above the oring in the pic) i'll bet that's what the problem is. at least i hope...

Cholleman

well i just moved the o ring to reflect where it is in the pic, but i'm not so sure that's the problem. the back of the oil filter housing doesn't appear to have oil on it as if it was leaking. after feeling back there by hand, it appears to be clean. the leak is on the passenger side. i snapped a pic so you guys can see. you can clearly see oil on the o2 sensor harness (yes my cam sensors are good. no oil in the plugs as of 5 minutes ago.) you can also see darkened metal from the oil leak below and behind the harness. any ideas guys?

Buellwinkle

I had something similar on my kid's SLK230 and it was just the head gasket leaking down the back of the engine by passenger side. Check with mirror to see if that's it. Also, what I did was to put a pocket digital camera in macro mode and take pictures close up where I can't see and then I can look at on my PC.

Cholleman

well damn, i hope it's not the headgasket. i can't imagine what else it could be actually. i mean, going that high up the engine, there's only so much there. i know there's going to be a lot to take off and remove, but if i were to take it on myself, is there anything special i'd need? i built this, so i'd think i'd be able to handle the headgasket:



then again, we did get a third party extended warranty. $200 deductible doesn't sound so bad vs. a weekend of the car being down.

LILBENZ230

Are you sure it's not something from the prior owner? Does the car request additional oil between changes? How many miles do you have?

Cholleman

car has approximately 61K on it. the oil was changed last winter/spring at the VW dealer where we bought it. the first time we saw the "add oil" message was a week ago, so i went ahead and changed the oil myself saturday. hope it's not the headgasket, but the car runs fine otherwise with no sign of coolant in the oil or white smoke out the exhaust.

Cholleman

i just read a post on another MB forum from a member that had a very similar oil leak to what we are experiencing. the member was advised that it probably is the vacuum pump for the braking system that is turned by the cam shaft. does this sound probable? only trouble is, there were no pics that displayed the exact location of the vacuum pump. can someone advise?

TruTaing

Hrm... Interesting. I just changed the oil on my friend's m271 yesterday and noticed oil around the pan and on the backside under the engine too... I couldnt find where it was coming from...

Im interested to see what comes of this..

Buellwinkle

This is what a mechanic told me is that you don't know how fresh the leak is, so put clean it up as best you can, drive for a week or two and see if it comes back.

As far as doing a head gasket. First you need a valve job gasket kit, about $100, that will have all the gaskets you need for the job. Then figure it's a 10-12 hour job for a trained mechanic, a lot shorter for an untrained one (you know, the guy with a lot of left over parts at the end )

C230 Sport Coup

I don't have the same engine, but my valve cover leaked and I had to tighten it.
Could that be all it is?

LILBENZ230

I agree that you should clean it up as best you can and drive it and see if it returns.

dinky228

hi, im new to the fourm. i just purchased a 05 c230k, i also noticed the oil onthe tranny. not as bad as Cholleman. i had cleaned it off, and week later i see it again. i traced it to a square like thin shap bout 1 1/2 wide has a air hose going to it, the square thingy is located onthe exhaust side of the head between the firewall and engine. bolted to the head. the square thingy has a lid which i whipped freash oil off of the bottom. i dont know much yet bout the benz. but hope my description help.

kickR

Cholleman ...

If you say it comes from the top, behind the engine cover, slightly to passenger side - chances are it is is that vacuum oil pump or whatever it is called.

I had mine fixed just before my warranty expired ($750 part) and was not surprised when the SA told me that this is a common and well known problem on the C-Class ... Those F***** lol

Good luck with it.

Buellwinkle

$750 just for the part, ouch, makes the head gasket idea sound not so expensive.

phoung

you forum jacker! go start your own lol. you should have bought a better benz my friend haha

LILBENZ230

This post was not helpful to either party, the original poster or the new guy. Posting in this older thread proved he was using the search function - something not many do. Had he started his own thread, he would have been told to STFF.

So perhaps you should stop "policing" and start "helping"?

Cholleman

i have done some searching and found one reference to the vacuum pump like you said i can't find anything further and so i haven't gotten anymore info on it. hopefully, i can find a replacement for less than $750. We did get an extended warranty on the car, but it's third party. after purchasing the warranty, i've heard some no so good things about them, and it carries a $200 deductible (obviously less than $750) if the part does end up costing that much, there are a few other things that are wrong that we could have done at the dealer to make the $200 worth our while.

jagass

This has happened to me before....

Cholleman

did you DIY, or take it to the dealer?

dinky228

okay, so today i took the part off the head. and took it to the dealer. the part is called a vacuum pump to camshaft housing. there are three gasket to it. but the dealer only had two.

gasket, part# 271 - 238 - 01 - 80 . price 12.75
seal ring, part# 668 - 997 - 01 - 45 . price 2.70

as far as the third seal ring which sit between the vacuum pump and the lid, the dealership couldn't get a part for it. so im trying to match up the seal ring with a aftermarket one. still trying to find one. the parts had to be ordered so i let you know how it goes.

Cholleman

awesome, thanks for the info. it sounds as though it's the seals/gaskets that fail and not the actual unit itself?