adham

iTrader: (3)

I bought a 2001 Z06 recently and it has an exhaust leak from the headers. I took the car to a shop to diagnose exactly where the leak is and they said it's from the gaskets. So I go to change the gaskets and the header bolts seem to come out very easily. I swap gaskets and then attempt to put the bolts back in. 5 of the bolts would go in all the way but never get tight. They just keep spinning. I can't pull them out by hand, they're not wobbly by any means, just won't tighten. Does this mean the heads are stripped? What are my options here?
Any help is appreciated,
Thanks.

94Z28-MSTGKLR

iTrader: (20)

Try swapping out the bolts between the holes to see if it helps. If not, it sounds like you either have a few bolts with messed up threads or your heads have striped header bolt holes.

adham

iTrader: (3)

I tried swapping bolts but it didn't help. The threads look fine on the bolts so I'm guessing its the heads. Can I try larger bolts? Or maybe try header studs?

Darkman

iTrader: (2)

You can try cleaning up the threads in the head with a M8x1.25 thread chaser. If the bolts don't grab after cleaned up with the thread chaser you can use Helicoil inserts (not particularly cheap).

scatillac

iTrader: (12)

Some headers come with bolts shorter the the GM OEM bolts. These are frequently stripped due to less thread purchase.

If this was the case with your car, it could be that the just the outer portion of the thread is stripped, leaving some deeper in the hole.

Using a piece of wire, check the hole depth vs the bolt length. If you're lucky, there may be enough threads to engage a stud. INOX studs with an internal allen are available from bolt suppliers as are flange head serrated nuts and these may work for you in this situation.

Put a bit of blue loctite on the threads, screw them into the hole and wait a bit, then install the header and carefully tighten the nuts, following the factory pattern and torque recommendations.

Good luck!