Need help diagnosing coolant in oil problem in '86 928S

[Paul-V.]

Hi Folks,

I was debating buying my brother's 928 but we think it's got a problem with coolant and oil getting in the wrong systems. It's a '86 928 with 133k miles. My brother has not really driven it in 2 years; it is in running conditions, but he has other cars and never really drives it (which is a bad thing since my experience with the 911 has taught me that Porsches don't like to sit idle). A few weeks ago he found a large puddle of oil under the car (it's parked in the driveway). He also checked the oil and found coolant in the oil--the old 'milkshake' effect with a white foam on top of the oil cap. To me, this sounds like an expensive problem to fix, but I don't know if it could be something else a little less expensive to repair. The car is otherwise in excellent shape. Any ideas of what to look for? Thanks.

[DPW928]

Could be a head gasket or, if equipped with an oil cooler in the radiator, the internal seals could be leaking. If it is just milkshake at the filler and not on the dipstick, this could just be the result of frequently starting the engine and not letting it get up to operating temps.

Dennis

[markmaunz]

Has the 928 ever ran hot? If yes, sounds like the head needs to come off, go to a machine shop for a check for cracks, and then reinstalled with new head gasket. You might be able to do a pressure test with a pump first but usually means 'head gasket' at minimum. Make sure your wrench does a coolant pressure test and hold pressure for 30 mins minimum and then pull all the plugs and turn over the engine slowly while watching to see if any water comes out of any of the plug holes. If you have water, this will tell you which head to pull and look for bad head gasket. Good luck! Mark