Om602 burning tons of oil and missing until warm - PeachParts Mercedes-Benz Forum

jake12tech · #1 11-03-2017, 07:39 PM

I'm going to do a compression test. When I was driving it last night, I drove it and noticed it had a weird miss after an old Italian tuneup. I shut it down and went to go start it this morning amd it was missing (not a dead misfire) and smoking blue like crazy. It did that until it got hot, and it was still smoking but not as bad according to the driver behind me.

What's the chance it's just rhe seals and not the guide? Can they be done with the head in place? I would think they could with a few tricks up my sleeve and keeping the piston and top dead center so the valve didn't drop. I don't want to do an expensive head job on a $600 car with 301k and Have the turbo seals blow two weeks later. I do like the car though and it's a pleasure to drive.

If it matters this car also had a bad algae issue that has gotten better with biobor. But the smoke smells like straight oil. The dipstick drops too.

jake12tech · #2 11-03-2017, 08:02 PM

Or if you have a cheap head with good valve stems, I'll take that too.

rbtoj · #3 11-03-2017, 08:03 PM

I would start investigating the turbo. If the seals on it are bad it will force feed oil to the engine (which by the way could cause a runaway condition).

Diseasel300 · #4 11-03-2017, 08:33 PM

I'd check the turbo too. My SDL slobbers on the compressor side. Bad enough for a haze and smell, but not bad enough to smoke out the traffic behind me. Check for oil in the turbo intake. If you don't have a ton of blowby, it's probably the turbo seals.

Rough start could potentially be a dead glow plug.

jake12tech · #5 11-03-2017, 08:47 PM

There's oil in the boot to the turbo but there is blowby that's normal for a 301k engine. How do I check the seals without removing the turbo and taking it apart.

jake12tech · #6 11-03-2017, 08:48 PM

Also should I check the intake crossover. I don't imagine that has anything to do but should I see oil in there. Also will radial anx axial play tell me anything

rbtoj · #7 11-03-2017, 08:59 PM

If you can reach the turbo impeller on the intake side you could check for shaft play, although the absence of play will not rule out a bad turbo.
EDIT: sorry, i didn't see your last post. Yes, axial or radial play is bad and will indicate that you need to rebuild the turbo.

jake12tech · #8 11-03-2017, 09:05 PM

There's up and down side to side can't check the in and out without burning my fingers. There was a drop of oil in the housing but blowby is in the rubber boot not soaked but wet with oil

jake12tech · #9 11-03-2017, 09:07 PM

Also when you put your fingers over the top of the valve cover where each cylinder is you can feel the hard vibration where the other cylinders feel smooth when it's missing and pouring smoke

rbtoj · #10 11-03-2017, 09:13 PM

Quote:

Originally Posted by jake12tech

There's up and down side to side can't check the in and out without burning my fingers. There was a drop of oil in the housing but blowby is in the rubber boot not soaked but wet with oil

I'd say that's it.
As for wet blowby, do you mean wetness in the blowby hose? If so, it's normal, as oil vapors will condensate on it.

jake12tech · #11 11-03-2017, 09:37 PM

Yes the blowby hose rubber boot from the airbox to the manifold.. I also checked it when the turbo was hot. Does that make a difference? There was just a small drop. And you're saying it could be force feeding the motor oil? Why would it run so bad when it's cold? It seems like oil is dripping in a cylinder causing it to miss. I'm not questioning your conclusion, but why would it run bad cold until its warm.

Diseasel300 · #12 11-03-2017, 09:59 PM

If the EGR is functional, the intake manifold is likely full of muck if the turbo is spraying oil. It's entirely possible that the valves are caked with a thick tar-like goop that could be preventing valves from fully closing/seating causing enough compression loss that it runs like crap until it's hot enough to overcome it. Just a theory.

If you want to see if the turbo is your culprit, pull the crossover pipe and pull the breather hose off. Let the engine warm up, then give it a couple good hard revs and see if you get an oil mist blowing up out of the turbo. If you do, you've likely found your oil consumer.

Father Of Giants · #13 11-04-2017, 12:12 PM

I'm more or less in the same boat. Engine "misses" on startup goes away when it's warm. I do have oil consumption, but am 100% sure it's the gasket to my vacuum pump. Oil consumption started after I replaced it.

My car will literally smoke out traffic if I put my foot to the floor. But under moderate acceleration there is regular diesel haze.

I'll try the crossover pipe breather hose method too.
But it seems there is no true way to tell if the valves and stem seals are good other than by pulling the head completely off right?

If so, I guess it's time to print out some FSM pages and get the researching on head removal.

Mxfrank · #14 11-04-2017, 12:32 PM

I had a problem like this and ended up replacing my turbo to no avail. If you have oil entering through the turbo boot in any volume, that's a problem and not ‘blowby’, which would only amount to traces of oil, It could be failed stem seals causing excess pressure. It could be a failure of the idiotic Pcv valve, which is hidden in the valve cover where it can’t be inspected or serviced. It could be a problem with the swinging door air mass sensor. It could be an obstructed air cleaner. And on and on. It’s going to take patience and insight to track it down.

jake12tech · #15 11-04-2017, 01:47 PM

Thanks Frank and Diseasel. I'll try those methods.

Giants: you don't have to pull the head. It's an overhead can engine, just pull the cam and use a heavy duty spring compressor for the valves and air through the glow plug ports so the valves don't sink. No need to pull a head to do stem seals.