I have an 85 GN that I expect has a blown header gasket, I am only getting about 6 psi of boost where I normally am getting over 12, the car is also making a ticking noise that I expect is the header gasket?. Am I thinking in the right direction will a blown header gasket cause me to loose that must boost, also how hard of a job is it to replace the gaskets and is there anything else that I should do while I have the car apart. Any feed back from somebody who has done this would be very appreciated.
Thanks in advance
Have you ruled out the possibility of a cracked header?These cars are proned to cracking headers.
I dont know if your car has been apart before,if
not use lots of penetrating fluid.My nephew had
an original 85 that hadn't been apart.Every bolt
on that motor felt like it was welded.You dont
want to break a exhaust manifold stud off.
Good Luck
WOW never really thought of that I hope that is not the case but I guess I will find out once I get it apart. Is there any area that is prone to cracking so I know where to look and if it is cracked can it be welded up or would I be better off just replacing them with an aftermarket set. any advice on a good set of aftermarket headers would be appreciated. I am still just keeping my fingers crossed that is just a gasket (I HOPE!)
They usually crack between where the three pipes
join into one.If you find a crack you will want to find somebody to weld it.The best way to weld a
header is to bolt it to a motor so the heat doesnt
warp it.If thats not possible weld alittle at a time to control the heat.Postons sells replacement
headers for $498.You could find used ones pretty cheap but eventially they will need welding.So if
your problem is a crack get it welded.Ive owned 4 GNs and my dad welded a header on each at least
once.
Take of the vacuum line and use a little tranny fluid and watch to see where your white smoke is coming from this will help you determine leaks if any. We were able to distinguish a leak around the down pipe and found a cracked header using this method.
CHECK YOUR LIFTERS AND PUSHRODS
I had a similar problem that turned out to be a bent pushrod actually a few bent pushrods and and few collapsed lifters!
This noise started instantly while driving the car and after the ticking noise started I cannot get anymore than about 6psi of boost which is why I was thinking it was an exaust leak, would bent pushrods cause the car to loose boost like that?
i have a similair problem on my car the guy i bought it from took off the whole turbo and got polished and chromed and we got it back to put it back together along wit the rebuild turbo kit i guess he didntreally know muck about puttin it together becuz it feels as if it leaks air somewhere and when i foolr it off the start black smoke comes out from the downpipe what can it be i need a little advice from u guys and tips ?