Seems the cooling system is pressurising when engine put under load , suggesting head gasket leak . Easiest way to check is to get a sniff test ( block test ) carried out and eliminate that possible cause . A pressure test on cooling system would should any exterior leaks i.e water pump etc . I would start off with these checks first before getting too involved with other possible causes.
Posted on Monday 17th of May 2010Don't understand this? Ask a question