New User. Problem hard start when hot

[Thabo 318i]

Hi Guys
I'm new and I own a 318i Individual 2004 model N46.
I need advice, my car has a problem starting when it hot. I have changed the crank sensor but still expirience the problem.

Any ideas?

 

[Thabo 318i]

Dealer told me that they diagnosed my car and they picked up that my top gasket is blown up but they unable to tell me how they picked up the problem. They can't even give me a diagnostic print out:yuck: