Motor oil in coolant problem
 

I have a question for anyone out there. I have a 1992 300 sl and the other day I noticed the expansion tank had oil in it. Also the fluid level came up and poured out the overflow.I know it is probably the head gasket but the car runs like there is no problem except for the oil pumping into the coolant.Could this have something to do with the oil cooler?I would appreciate any input. Thanks

It could, but headgasket failure is common with this engine.

Replaced head gasket on my 300SL at 90K miles. A common issue. I'm told ( by MB service department ) the new gasket will last longer due to improved materials.

x2 on the head gasket. No other path for oil to get into the coolant.

oil in coolant
 

Thanks for the info.I guess I will attempt to replace the head gasket myself.I could sure use all the help I can get from all of you out there.Thanks Again

Obvious but still have to say, hopefully you aren't starting it or driving it. Get it fixed.

And yeah, head gasket.

did you check if your car has an oil-coolant radiator? My 1993 250D W202 has one and I had the same problem, it was that part, I changed it and no problem.

Rather than start another thread with the same problem I mentioned I had this problem with an 88 300E (200K km) I recently bought. Intended as a parts car I went over it and it turned out to be in better condition than my plated 88 300E.

That said I have a brown mess in my reservoir as well. The car does not smoke in the least. Runs smooth, does not overheat, does not boil the rad - no smoke whatsoever from tailpipe. Oil is clean, good oil pressure, no sign of water or coolant after an oil change or on the dipstick. I have to drain and flush rad and lines and start fresh. (assume ten minute flush product is ok?)

Wishful thinking has me hoping somebody put oil in the reservoir by mistake. (former owner fairly car clueless).

I'm ruling out an oil cooler in an 88 300E which spells either transmission fluid making the coolant a milky thick brown stuff or worst case scenario head gasket. Without water in oil or white smoke to the tailpipe how can it be a head gasket would be my last question?

Rarely does the head gasket on the W124 cause white smoke out the exhaust (coolant in combustion chamber). And also very rarely does coolant get into the oil. 99% of the time it's oil in the coolant only.

I bought my car with this problem. Oil in the coolant tank only. Ran like a top no power issues, no cooling issues either. But there is no doubt you need a head gasket.

Wondering how long you drove your car like that? Also, at 190Kkm is there any chance that simply re-torquing the head bolts would make enough of a difference? It's the worst time to have to do a head gasket for me for a few months.

I put roughly 1000 miles on the car and I wish I hadn't. It totally fubar'ed the cooling system from head to toe. After completing the HG, it took a new radiator, expansion tank, new hoses all around, 4 flushes, and about a years worth of wiping the excess oil out of the coolant expansion tank for the system to become clean again. A real pain. Remember that it's also gumming up your heater core, etc with oil. It's probably not good for the water pump either.

It's not a matter of the head bolts being loose, it's a break in the actual head gasket material which is allowing oil into the coolant passages.

Not sure what to tell ya. :(

Thanks for the input JohnM.

Good to know the extent. I knew the oil would rot the rubber but hadn't thought it that far through. I've got quite a pair of 300e(s) bawling at me for money to go their way.

This and my other 300E in another thread with the low idle issues("fixed") has some blue smoke at low RPM and idle from what appears to be the #6 cylinder (one only, fouled plug). This car could be straight traded for an '87 with 300K km and a bad interior. That would be the end of high dollar failed e-tests (cutoff date is 1988 in Canada), but oh that interior.

Decisions decisions

Doing the head gasket should only take a long weekend (Friday-Sunday). You only have to replace the gasket and head bolts at the very minimum (<$100). Don't really need too many special tools, it's just a long process! There are a few great posts here that helped me greatly when I did my HG.

If the stuff in your coolant is a reddish "strawberry milkshake" type goo, STOP DRIVNG IT. When I had the same problem on a different type vehicle, the transmission oil cooler inside the radiator had failed, and I was cross-contaminating the coolant and transmission fluid.

The fix was a new radiator, but the 'collateral damage' included a transmission rebuild, new water pump, hoses and a lot of flushing and swearing. :eek: The heater core went about a year later, but I'm not sure it wasn't related.

If lucky, the tranny would only need to be flushed aside from the radiator replacement and cooling system flush.

Just a warning of a possible situation that should be checked out.

Scott

I've done many small block 8 cylinder GMs and other domestics, years before the pollution controls mess they cram into motors today, easy sailing.
Any articles I've managed to find specific to the m103 point to the timing chain being the only sticky bit.

Swapping a whole motor with one that passes the acid test out of a wreck
would be easier than changing a HG. There seems to be literally a dozen in my area and there would be nothing stopping me from helping myself to a number of them if it wasn't impossible to find a place to store them.