i wonder if anyone can tell me what may cause this, i was giving my cossie a real hiding last night , when i raced a new bmw and an evo i left them both in my rear mirror according to my speedo it was 155 mph, when i slowed down i realised my engine was knocking, i creeped my car back home which wasn,t far on lifting the bonnet i realised the header tank was swollen and split on the weld all the water was gone and the car sounded like a london taxi, i will have to take the engine out tommorow and find out what damage has been done but wondered if anyone knew why it would pressurise like that cheers cosbag

 

failed headgasket would be a good guess!

 

as above