[DaveBoettcher]

1988 944S with 158k miles on the clock. I use her every day.

Because oil was getting into the coolant I had the oil cooler gaskets changed in April at the local Porsche specialists I use.

In May I had the coolant temperature switch and a hose changed at a different garage. This second garage noticed that there was some oil residue in the coolant header tank and did a bit of investigating. They said they were getting an HC reading of 18ppm from the coolant filler opening and that this showed a head gasket problem. I didn't take too much notice of this at the time because I thought it must be something to do with the oil cooler problem.

However I have just had the second garage check the reading again and it has gone up to 42ppm. They say this is an early indication that the head gasket is going. I queried whether evaporate from the residual oil in the cooling system could cause the reading, but they said the Crypton equipment they use can distinguish between oil and fuel hydrocarbons.

Anyone got any experience of this? Is head gasket the correct interpretation? It seems weird that both the oil cooler gasket and head gasket should go so close to one another - but then again the car is 21 years old.

If it is the head gasket, what is the likely cause of failure, and how likely is it that the face of the block or head will be damaged? Will I be able to just put in a new gasket, or will the head or block need skimming and how practical is this?

Thanks for any help.

Regards - David