I stripped the bolts on my exhaust manifold flange, where it connects to the downpipe. What do I do now?

 

Dorman sells a kit for those bolts. Check with Advance, O'reilly Auto Parts. They're actually drive studs.

You have to hammer the old bolts out and hammer in the new ones. A PITA to get them out/in when the manifold is installed on the engine.

 

Just my luck.. Maybe I'll just get a shop to fix it for me then...

 

Strange.. my '91 had just regular through bolts. I replaced them with Grade 8 bolts and nuts long enough to compensate a lock washer on each side. So far so good with a new downpipe seal.

 

Mine is a 1990, guess they changed it that year.
I don't want to start smacking it with a hammer, think that would maybe crack it further upstream..

 

You'll have to cut the bolts next time you go to remove them.

 

Curious as to why? I put those bad boys in when I did my header install however long ago. It wasn't until just a few months ago that I took them back out to replace the solid flange seal that was chewed on the sides with one I got from Advance. Also tossed the lock washers on. I've removed those bolts 3 times since I put them on with zero issue.

 

Over a few years the heat cycles essentially lock the nut and bolt together if they are both steel. That's why a lot of the bolt kits come with a different nut.

 

Do you think it is possible to rethread while it still on the car? I only need about 5mm to get to the good threads.

 

Bummer! What do you mean by "good threads?" . If I could just add washers and have my nut grab good threads I might accept that.

 

Any "redneck" fixes for this?

 

How is the stud in the flange? Is is pressed in like wheel studs or threaded like the manifold stud?

If its threaded, I'd just use the two-nut method and remove the stud altogether. Slap some new grade 8 or stainless hardware on and be done.

 

I can't really tell if its pressed or screwed in since my face doesn't fit in between the pipe and block...
I'll try and put a jack under the pipe to get it all the way up so maybe I can grip the threads.

 

Just checked the '92 and '99 IPC. They both take the same studs. Part number J4007109.

Here's what they look like:

http://www.oreillyauto.com/site/c/de...2419&ppt=C0022

Stupid name: "Exhaust Manifold Bolt And Spring". What "Spring"? LOL

I bought these and used stainless steel nuts instead of the carbon steel nuts that come with the kit.

Edit: 3/8" diameter threads.

 

How badley stripped are the threads?

3/8-16 threads (original) is close to M10-1.5 threads except the M10-1.5 threads are little finer.

You might try screwing an M10-1.5 nut on the butchered stud and see if it catches. Even if it does it may not hold on very long.

In the long run you may end up removing the exhaust manifold and removing the old studs and installing the new Dorman studs. If so, cut the old stud off next to the flange, heat it up with a torch or MAPP until it turns red, then using a punch and a BMFH, punch out the stud.