Oil leaks are driving my crazy

[cheeseraid]

Alright, my Benz wants a new part but I can't figure out what it wants. It's a 190e 2.6 auto sportline (and if it keeps this **** up it's going to be a 190e 3.2 m104 lol). I keep having oil leaks outta the valve cover gasket, oil pan, and rear main seal. I fixed the valve cover and oil pan a few times now but they keep leaking like the car has high oil pressure. I cleaned the breather out on the valve cover and checked the oil passages on the top. Still didn't fix the problem. My dad thinks it's the oil pressure relief valve, he has a 66 bug that has the same kinda system. Go figure, Germans never change things lol. From what I can find though is that valve only works at full oil pressure. I don't have a spare gauge to measure if it's going over 3. When the motor is idling it hovers around 1.8 - 2.2 bars never lower. I remember about a year ago it was around 1 - 1.2 so something is off. As soon as the motor hits 900 rpm it pegs 3 bars. I'm running 0 - 40 Mobil Euro Synthetic in it like always so that can't be it. I have a slight amount of lifter knock but that's normal for my oil. I also noticed since this has started it won't idle smooth. The motor is dialed in right. 52 degrees on the dwell at idle 42 degrees at 2500. The plugs are burning smooth and the caps and wires are good. Cylinder pressure is all above 180 on each cylinder. Anybody got some ideas? I took it to my local indy and he said to run less oil in it. WTF, I can't keep the whole 6 quarts in it lol. It leaks out about a quart in a month, dosen't burn it, just leaks it. Thanks guys.

[big dog 2]

Yea, mine leaks too! Mostly from what appears to be the rear main seal and it is just starting to leak in front of the engine too. Probably the usual timing chain cover leak or roundabouts.................Not nearly as much as yours but annoying anyway. My oil pressure and plugs are like yours too and the engine runs just fine but is getting old and incontinent.................

[johnjzjz]

Syn oil is a great product and the internals of a motor Love it BUT the older cars seap all over the place with it

if you go back to dyno oil you will also not be happy < reason the power switch will feel like it was turned off

you could use the Right Stuff sylicone and glue it all up but some dont like doing that i would but that is me -- jz

[ps2cho]

Originally Posted by johnjzjz

Syn oil is a great product and the internals of a motor Love it BUT the older cars seap all over the place with it

if you go back to dyno oil you will also not be happy < reason the power switch will feel like it was turned off

you could use the Right Stuff sylicone and glue it all up but some dont like doing that i would but that is me -- jz

Why are you suggesting running Synthetic oil increases power?

[cheeseraid]

The car has always had mobil 1 in it from the second oil change, I have the documents on it. I don't understand why it would be that. Last time I resealed everything I used gm red gasket maker with the seals and it is pushing oil outta that. That's gotta be an oil pressure problem. Maybe the oil pump is acting up. I don't know why cause there is no sludge in the motor. Idk how much of a pita that would be to change. On the way home today the oil light kicked on again, I just put a quart in it two weeks ago. It's so dang cold out and I don't feel like resealing everything cause it's just going to leak out again.

[anthonyb]

I don't know about the oil pan leaks, but the valve cover and the front timing chain cover will leak if:

-The sealing surfaces aren't scrupulously cleaned before installation.
-Using the wrong (ie not the black MB or Loctite equivalent) or expired sealant.
-Using sealant in the wrong places.
-If your valve cover is warped, as can happen with prying to remove it or not torquing the bolts down evenly to 8-10 Nm.

Oil pressure isn't the problem here, I don't think any of these gasket surfaces are exposed to the pressurized oil system - they just get splash. I also don't think using synthetic is a big part of your problem, but that is just me.

[junqueyardjim]

The problem is not oil pressure. Oil pressure has no connection to gasket leaks. Gasket leaks are an owner problem on any engine that isn't under warranty. Gaskets are cheap. Buy some new ones and install them correctly and you will take care of the problem.

[johnjzjz]

Originally Posted by ps2cho

Why are you suggesting running Synthetic oil increases power?

For many years now we have been racing and motorcycles have an easy tool a chassis dyno - in using it for 25 years you come to understand and see things that make power NOTE : ( In the speed that a unit will make power and having computors today laying them over each other ) Grafts are a neat tool --- making one change at a time using a MULE motor in a bike will show you things, before doing it you would not believe -

Syn oil not all but select product, can and does make power you can see live on a dyno -- if you need more into i can provide --

Mobil 1 Royal Purple Red Line are a few that do just that < jz

[big dog 2]

Guess there are no quick fixes for oil leaks...........I don't want to put in any additives in the oil fearing something else could happen.

[Ferdman]

cheeseraid, how many miles are on your 190E 2.6? It's possible that the engine needs major work (e.g. piston rings and valve seats) and that blow-by causes the oil pan and valve cover areas to become slightly pressurized when the engine is running which causes oil to be forced past the gaskets. Suggest doing a compression check to help diagnose the cause of excessive oil leakage. Worn valve stem seals would cause the engine to burn oil. Check the spark plugs for oily deposits.

[dhjenkins]

Run the engine with the oil filler cap off. If it blows out like a leaf blower, you could either have piston blow-by (not likely due to compression readings) or PCV system issues.

An over-pressurized crankcase will blow oil out anywhere it can.

[ps2cho]

Originally Posted by johnjzjz

For many years now we have been racing and motorcycles have an easy tool a chassis dyno - in using it for 25 years you come to understand and see things that make power NOTE : ( In the speed that a unit will make power and having computors today laying them over each other ) Grafts are a neat tool --- making one change at a time using a MULE motor in a bike will show you things, before doing it you would not believe -

Syn oil not all but select product, can and does make power you can see live on a dyno -- if you need more into i can provide --

Mobil 1 Royal Purple Red Line are a few that do just that < jz

Interesting, although I would imagine the difference is very negligible?

[long-gone]

In the older 1980s Volvos (and late models too) keeping the PCV system clean and free flowing was a very common and important issue. A clogged system would build pressure in the crankcase and wreak havoc with everything from bad oil leaks to blowing so much oil into the air cleaner that it soaked the filter.

The common DIY diagnosis called for a "rattle test". You unscrewed the oil filler cap and let it rest on its opening, if it just vibrated there quietly your PCV system might be deemed clear and flowing properly. If it rattled and bounced all over, the system was clogged. I had an '86 240 that was consuming lots of oil and sprouted a few minor leaks, no smoke though. When I did the test the cap bounced around and jumped right off an otherwise smooth running engine. Sure enough the fire trap was almost totally blocked. When cleaned, everything went back to normal and the cap vibrated quietly on the cover.

I'm not saying this is it on your car, and benzes don't have a fire trap in the PCV system, but an occluded breather system would likely build pressure in the crankcase of any car and maybe enough to force oil leaks. I'm not even sure if a "rattle test" would be an indicator on a Benz, but I would think it might.
Maybe it could be something as simple as the need for a new oil filler cap (which are vented and can and do get clogged).

Note: If the filler cap is itself the problem, the rattle test would not show it.

What I'm not clear on is if a clogged breather system could have any effect on the actual oil pressure. I'm not inclined to think it would so I don't see any correlation with the increased pressure and the oil leaks (except maybe the rear seal).
One common leak that can be substantial yet hard to spot on these is the oil level sender mounted above the oil drain in the pan. The seals tend to leak as well as the unit itself through the plastic housing around the electrical connection. When they leak the oil tends to spread thin across the pan below it, running off the back of the pan and into the airstream while the car is being driven making it hard to see and determine how bad the leak is.