Jeremy

I am thinking of purchasing a 2004 cayenne turbo as my winter car. Car is generally in good shape. I was surprised to find oil in the coolant resevoir. My understanding is that coolant lines and coils were replaced in last year by dealer. I believe the owner to be honest and he stated the dealer ran a compression test and he was told all was fine. Would there be any other reason to find black sludge in the coolant resevoir other than a leaking head gasket or cracked head? Many thanks -

Jeremy

hahnmgh63

Sounds like the beginning of the oil/coolant heat exchanger seals starting to go. Need to be fixed soon before it does damage.

Jeremy

Many thanks - any idea as to cost?

hahnmgh63

If it's the oil Cooler it isn't too cheap at $262 and all of the seals are only around $20. Maybe someone willl chime in here if there were any problems with these in the past as Porsche has always had problems with their choice of Oil Cooler seals.

Jeroen Pipelers

I think this has just happened to me. Light coolant low came on so i headed home asap. What i saw to my suprise was milky brown water in the expansion reservoir, also the engine oil is low. With no water in it. This has to be oil cooler am i correct?

J'sWorld

I doubt that the heat exchanger is at fault. It's not likely by design. The cooler is brazed as one piece and the oil and coolant areas are totally separate. If the o-rings going from the H.E. to the housing were out they would leak externally onto the unit. There are two hard lines that carry coolant to the H.E. Leaky connections here would also leak externally. Unless your H.E. is ruptured internally I don't see how the two fluids could mix.

You can buy a tester kit to check for combustion gasses in the coolant.

Jeroen Pipelers

You are thinking head gasket or worse? I was thinking/hoping something to find the leak externally because there is a whole lot of oil in my coolant. Head gasket would not leak so much it seems.