It could be lifting when hot or under boost, as I said earlier grab the test kit from Napa and see if there's combustion gasses in the coolant that will tell you one way or the other.
Damn and here I was thinking I had helped way back at the start.......
Sorry didn't realise I had to be a subject matter expert to post correct information....
I'd just increase boost until it rattles slightly then back it down 3>4 psi and be happy knowing it's safe.
Too many people get caught up in the numbers chase.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.