Lots of oil in the spark plug chamber
 

So we change the spark plug today and we pulled the plugs and found that spark plug number (cylinder number) 1 2 4 6 has oil covering all over i mean top and bottom drenched with oil, but here is the twist it dose not smoke meaning it dose not burn oil, but what's strange is the spark plug are not even tight they are so loose you can unscrew them with your pinky with VERY little force... Number 3 and 5 were hard to open but there were no oil...So since there is NO oil spraying on top of the piston, where is this oil comming from???

Hmmm
 

I am guessing this is the 1995 E320 Special Edition 202,000 miles.

Diagnosis should start with:
* Replace the leaking valve cover gasket.
* Replace the spark plugs, MB# 0031596703.
* A cylinder leak down test.
* A compression test.

Checking for worn out valve guides and seals, and/or bad piston rings.





Have a great day.

We replaced the spark plug we will check the spark plug next week to see any oil

They should be tighter than that, I think its like 10-15 newton meters on a M104....

I am guessing the spark plug was not too small to be tighten,

I would check the valve cover gasket.

Also, make sure the breather hole isn't plugged.

I am guessing that the oil is not coming from inside the cylinder and blowing past the spark plugs. If you had that much oil going into your cylinders, you'd be having much more trouble.

More likely is a bad valve cover gasket or some PCV issues or both at the same time.

How dose a bad valve gasket cause oil to go up to the spark plug chamber???

What motor are we talking about here?

The valve cover is higher than the spark plug holes on every engine I can think of......

If this is the '95, and this is the first time you've had the center cover off of the car, is it possible that the PO was sloppy when changing oil and got it into the holes below the cover from spilling?

Answer
 

The spark plugs go through the center of the valve cover = there are six ring seals = one for each spark plug passage through the valve cover + the large roughly rectangular outer perimeter valve cover gasket..

Leaking valve cover spark plug passage ring seals is common...

Oil leaks through the ring seal area, and drools down pooling around the spark plug = if the plug is loose, every intake stroke sucks oil in.

On rare occasions, I have been forced to use a ShopVac to suck out enough oil to find the spark plug.

I'd think that a mityvac or topsider would be less messy.

The identity of the motor is highly confidential, and even if it wasn't it would be a lot of trouble to post it. It's really more sporting to just take wild shots in the dark anyway.

Although I appreciate the humor and message of your post Dean, I think that two out of three cars in the sig being diesels leaves us one logical alternative.

Two requests for the model, both ignored. The point is you get more out of a thread if you provide some basic information, absent the detective work. A handful of keystrokes is not that hard and goes so far.

Sorry its a M104