Oil In Coolant; Possible Causes?

[BMWtyro]

I have found what appears to be motor oil in the coolant in the recovery tank of my 1984 320i Eurospec (M20B20 engine); the blue coolant is now brown in color. Curiously, there is no evidence of coolant in the crankcase when I check the dipstick. Also, the car emits no steam from the tailpipe which suggests to me that coolant may not be getting into the combustion chambers.

Is there anyplace else that I should look for a source before assuming that it is a blown head gasket or a cracked head or block? I really don't want to pull the head if doing so is not a slam-dunk, but I can't imagine where else oil is getting together with coolant. Suggestions . . ?

Jeff

[95BMWIC]

You are on the right path - IMHO - head gasket . Might even explain your issues from the other posting - missing, stalling..

tests I have used for head gasket diagnosis..

Pressure test the cooling system
Leak down test
oil analysis
Compression test - may or may not - although it will confirm a major issue

[BMWtyro]

Thanks, 95BMWIC, but these are two different cars. The car with the missing/stalling/etc./ problems is an '87 325e, the one with the oil in the coolant is an '84 320i Baur.

Jeff

[82eye]

your suspicions are bang on. it won't be more than a head gasket. check the head for warp as well, outside possibility it could need a reface.

[BMWtyro]

Thanks, 82eye; I think I may let my BMW guru handle this one.

Jeff

[richardodn]

There's an oil passage between the block and head on the exhaust side between cyl 3 & 4. Look on the side of the block in that region and see if there's any oil seepage down the side of the block. It's fairly common to find. What ends up happening is that the seepage ends up making its way to the coolant passages. As the oil is under higher pressure than the coolant, transfer is in one direction. I do recommend using the original BMW head gasket set and avoiding the Victor Reinz kit. In my opinion, that VR kit is much more sensitive to surface prep and the BMW part is a superior part. Although I've not used them, I've not heard anything bad about the Elring kits.

[BMWtyro]

Thanks, Richard; you always give me good, usable info. I appreciate that. What is the best source for a BMW Genuine gasket for my Eurospec oddity?

Jeff

[richardodn]

Be sure to verify this on realoem with the VIN. I'm assuming you're talking about the Baur. The top end gasket set which includes the head gasket is PN 11121730876. My current go to for original BMW parts is bmwpartsdeal.com where it's $288 (MSRP $374). The gasket all by its lonesome is PN 11121722728 and $126.

[BMWtyro]

Thanks, Richard!

Jeff