exhaust leak -- disgusted

[mjtjnj]

Getting disgusted with my MJ. Mostly venting.

I'm trying to get all the mechanical bugs done before getting into the floors, then paint. But man, one thing after another. Been using her quite a bit lately.

 

When I had the engine rebuilt last summer, the builder screwed up installing the valve stem seals. I pulled the head off, after just installing the whole thing, and he fixed it. I reinstalled, new intake/exhaust manifold gasket, torqued down the Clifford header, and used (red) Loctite on the threads.

 

Well, recently a tapping started, and it sounds an awful lot like an exhaust leak. The guy who installed my SS system took a look on the lift, and said it looked fine, he didn't hear any exhaust leak "unless it's coming from up top." He didn't look up top.

 

I did, and I found some air coming from the EGR tube. When I installed the header, the EGR tube no longer fit, and my brother cut/fabbed/welded it to make it work. So I took some Quiksteel and spread it over the welds, sealed it right up. Only problem is, the noise is still happening.

 

It's so tight in there, and gets so hot so fast, I can't feel around real well for a manifold leak. It makes no tapping at idle, or even while revving the engine, only while driving. Maybe it's not an exhaust leak - but then what is it?

 

If I have to pull that manifold again, I'm going to be sick, and I'm sure the red Loctite is going to cause problems....any ideas? Someone tell me I shouldn't drive the truck into a bridge abuttment! LOL

 

Tom

[dasbulliwagen]

I can't say for sure that this is your problem, but some headers make noise like that in normal operation, it is like a pinging of the tube from the gasses hitting it coming out of the exhaust port. Or could be the header exhaust flange to the head is not straight and not tightening down to the head fully.... Youd have to pull it apart again to know if that was the case. Ive also heard of one header port having casting flash or something causing it to not seal properly. Good luck.

[jimoshel]

:agree:

It's also possible something in the drive train and not the engine. Loose brake shoe. Shock absorber mount, Spring bushing, etc. Been there and I know it can be a bi,,,er, difficult to pinpoint.

[mjtjnj]

Thanks for the replies. I've been driving it for a year and a half without this noise, so I don't think the header sealing up to the head is the problem. The exhaust gasket was semi-metallic and nice and thick, and I put a new one on when I had to take the head off. The loctite pretty much throws out any loosening up, but maybe I'll try to give them a little bit of a turn, in order. Just don't wanna snap them! Assuming they didn't loosen up, the gasket SHOULD be ok, right?

 

It just SOUNDS like exhaust to me. Is it helpful to have someone plug the exhaust pipes and feel around in there when the engine is cool?

 

Thx

Tom :ack: