Instant exhaust leak while driving!

[jly535]

While going to work yesterday everything was normal then bam, major exhaust leak. So I limped it home and jumped in my truck as not to be late. I assumed I lost a bolt or cracked the header.

After snooping around and not seeing any missing bolts or cracked welds. I finally came upon a threaded plug that had loosed up and blew out (very relieved).

So what are these plugs called and are the supposed to be tightened flush? I noticed that all had a different amount of depth (like others were coming loose).

Thanks,

Edit: Ok it's a Barrel nut

[jly535]

Ok maybe they're not barrel nuts. These are angled and have nothing to do with the exhaust mounting flanges.


I have an aftermarket exhaust if that matters.

[infraredcalvin]

Are they plugs for the old air injection system? There are six of them.

[jly535]

Originally Posted by infraredcalvin

Are they plugs for the old air injection system? There are six of them.

Yes probably, they're angled at a 45* compared too exhaust flange. It's a 77' Non-catalyst if that matters.

[turbobrat930]

yes, they are the plugs that are put into the heads when the air injection system is taken out. I think pelican has them. if not, try EBS (Engine Builders Supply), or one of the Porsche machine shops ( JB Racing, etc)

[infraredcalvin]

Notorious for falling out, there are a couple of threads on this, some guys swear by high temp loctite, while others have safety wired them to keep from backing out. If you need a replacement, they are avail through our host, they are the same part as the 914 rear caliper adjustment plugs, or something like that...

[jly535]

Great guys, thanks

i'll get one from here and probably try the loctite.

[mark houghton]

Originally Posted by jly535

Yes probably, they're angled at a 45* compared too exhaust flange. It's a 77' Non-catalyst if that matters.

Yes, most likely the air injection plugs. But the big question: Why would a '77 non-catalytic coverter car have air injection in the first place? I don't know what years that the US emissions standards dictated that air injection into the exhaust manifold would be required to clean up the emissions.

[jly535]

Originally Posted by mark houghton

Yes, most likely the air injection plugs. But the big question: Why would a '77 non-catalytic coverter car have air injection in the first place? I don't know what years that the US emissions standards dictated that air injection into the exhaust manifold would be required to clean up the emissions.

I don't belive it had an injection pump, plugs from the factory maybe as a crossover year.

[infraredcalvin]

My 76 has air injection pump, ca car though.