Author Topic: 1990 jetta 1.6l has oil in coolant (Read 7253 times)

jtexcell · « **on:** August 07, 2007, 06:37:49 am »

Looking at buying a 1990 Jetta diesel, 1.6l, 5 speed with 135k miles on it. Runs well, but has oil in the coolant tank. Is this a common VW problem? How serious is it? Head gasket or leaky oil cooler? I need some feedback on what to look for and level of complexity to fix. I am a competent VW gas engine mechanic, but am new to VW diesels. Suggestions? Car is priced right at a couple hundred bucks. I don't mind fixing it, but would prefer to stay away from a science project. Thanks.

smutts · « **Reply #1 on:** August 07, 2007, 07:35:56 am »

Are you sure it has an oil cooler? If so it will be an aluminium thingy which the oil filter screws against, with small coolant hoses too. Same as the Gti.
With the engine cold, start her up, run for a minute and shut off. Hoses rock hard? Head Gasket dying. But do check that no one has left the cap loose or "modified" it so that this tell tale is masked.
Hoses feel normal? Then you might be in luck. 90% chance ots oil cooler, 10% its a cracked head or gasket problem. This was where I was with a £500 GTD, New oil cooler is not too fiddley a job, you might as well change oil & filter while at it. There is a 27mm nut that holds it on (same size as injector socket), get some long nose mole grips to deal with the b****y hose clamps etc. You need to get rid of the oil though, so keep changing the coolant with STRONG solution of washing machine powder, (NO caustic soda, or washing soda or the alloy engine parts will dissolve like sugar!) I did it every day for a week after driving from work.
Best on a hot day so as to get a good dose through the radiator, or muff the radiator, and watch the temp guage!
Oil cooler £30 parts.
Hmm, after reading that, I can see that my english teacher might have had a point.
:roll:

saurkraut · « **Reply #2 on:** August 07, 2007, 08:37:06 am »

I have had head gaskets leak oil into the water, but not combustion gasses. Changed the oil cooler, problem was still there.

As a mater of fact, I've never had an oil cooler leak into the water jacket. I've heard about it, but never have seen it.

Any one actually have an oil cooler fail this way?

jtanguay · « **Reply #3 on:** August 07, 2007, 03:11:47 pm »

i've had that problem... car seemed to run fine, but my oil level kept going up! i was wondering wtf is going on!!!

once i was driving the car nice and hard and i left it running when i got home... car sounded real weird so i popped the hood and my oil filler cap was just bouncing. :shock: somehow it worked itself loose from all the pressure... i did put it back on, but maybe not tighten it fully? i'll never really know what happened there, but after changing the oil cooler, all of my problems were gone! (i did have a little bit of oil stain in the coolant bottle too)

Doug · « **Reply #4 on:** August 07, 2007, 05:15:18 pm »

I'd put money on the head gasket being the source of oil. Pull it apart and put a fresh one in. Get yourself a book so that you can read up on the proper installation procedure.

lord_verminaard · « **Reply #5 on:** August 08, 2007, 07:10:02 am »

Happened on my 8v gasser ScirccoII. Car ran fine, but one day the oil light came on. Shut it down and opened the hood, oily sludge coming out of the coolant bottle.

Remaining oil in the engine was clean. The coolant pipes in the oil cooler can corrode and since the oil pressure is higher than water pressure, the oil shoots into the coolant but most of the time there will be very little coolant in the oil. A quick and dirty test is to splice the coolant lines to the cooler together, and cap off the outlets on the cooler, drain the oil and coolant, re-fill and drive it around. If everything is clean, you've found your problem. Or, a more tricky (and dirty) method is to pull the coolant lines from the cooler, splice them together, and start it up. If oil shoots out of the coolant lines, then you know it's focked.

Brendan

smutts · « **Reply #6 on:** August 08, 2007, 12:41:16 pm »

I was lucky then?

Makes a change!

dieseldubber · « **Reply #7 on:** August 20, 2007, 10:07:49 pm »

hey just discovered oil in coolant after replacing burst rad hose. I cannot detect any coolant in the oil though. Someone suggested presuure testing oil cooler and if its good then its probably the head gasket?? Any other suggestions on how to get to the root of the problem and also how to clean up the oil after the fix. I guess leaving too long could cause all kinds of problems eh? Thanks.

Author Topic: 1990 jetta 1.6l has oil in coolant (Read 7253 times)

Doug