Arrgh -- exhaust manifold bolt stipped!

Well, I might have found the source (or one of the many sources) for the throttle lift-off backfire. Going on a suggestion from one of our fellow members, I went to check the torque on the exhaust bolts. The one nearest to the firewall was not up to torque specs probably closer to 15'/lb instead of 34. When I tightened it, it wouldn't tighten.

Took it out and it was totally stripped.

Now I have to 1) find a replacement and 2) figure out if the hole is stripped too, and if it is, get my mechanic buddy to tap it for me.

Arrgh!

Sam:

Sorry to hear about your problem, at least you found it. Better check to see that the exh gasket didn't burn through if it was leaking at all.

Good luck!

Hi Sam, glad to hear of your progress. At this point you may as well disconect the manifold from the head and give a good "look see". You may find no manifold gaskets, however, I would put them in.

Steve

Ahh Gary -- great idea!!!

In doing what you suggested, I found the bolt below the stripped one totally missing -- which now makes sense. One was missing, which put stress on the top one, causing it to strip. I think the gasket is probably burned to a crisp.

I still need to remove the bolts holding the manifold to the down pipe before I can move it to see the damage to the gasket.

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by steve99:

You may find no manifold gaskets, however, I would put them in.

Steve<hr></blockquote>

I just picked-up the Vicky Brit catalog to see how much gaskets were and I just noticed the "gaskets were only originally fitted to fuel injected cars." Then I saw your post, Steve...funny.

I don't think there is a gasket in there, because it looks pretty original. Will put one in there, though!

My guess is that this really does explain the backfire. Heck, if I was down one-and-a-half bolts and no gasket on one side, that would cause a leak!

Oh, I also decided to take off the hot air return. Since I'm not planning on driving it in the cold, and I realized it's just bolted to the manifold. Looks better without it.

Cheers!
Sam

I pulled my preheater off last summer and never had any problems. I ran it last fall in temps down to mid 30's. I do however tend to let the engine warm up a couple of minutes prior to driving it though. Not because of the lack of the preheater, just because.