I have a 1994 945 that has develop a nasty knock at idle that only happen when the outside temperature is below 45F but goes away when the car is warmed up. It doesn't sound like it is piston slap mainly because its louder and it doesn't do it when the outside temperature is above 45F. There is no power loss but the vacuum at idle when it is knocking and not is a vibrating 16-17. I think the knock is coming from the head but it really hard to tell. I run Mobil 1 in it and it has had a tune up w/ all new belts.
So is it a head issue or something else?
Adam
|