I have a 2003 XC70...with 100K miles. Love this car! However, I?ve had the car back to the dealer 3 times for a ?hot start? problem. The car makes a noise (knocking/clanging) upon firing ONLY when the engine is hot and has sat for 30-45 minutes. The noise stops in about 2 seconds and will not reocurr upon restarting. It doesn?t make the noise at cold start. In the winter, it?s minimal...in the summer, it?s horrible. The dealer has
*replaced exhaust manifold gasket (even I knew that wasn?t the problem!) *replaced the timing belt and ?tensionor? which they were sure was the cause...NOT! *replaced the oil pump seal...I picked the car up today and the noise is still there.It?s obviously caused by heat build up. What on/in the engine could be the cause of this mysterious noise? Any ideas? Thanks, Volver