Exhaust leak?

[PATRICKH]

I started noticing what sounds like an exhaust leak on the passenger side of my truck last week. When I got a chance to check it out, it sounds like its coming from the front of the engine, right up under the altenator. Could this be part of the air injection system ? I had a similiar issue on an 84 monte carlo several yrs ago (had the 305) and I ended up plugging the lines for that system. (red kneck engineering)

I can't think of anything else that would cause the noise. I don't hear it at idle, only under accleration. Any ideas?

[northsnoma]

Exhaust manifold?

[killian96ss]

Sounds like a normal exhaust manifold leak! My SS has one right now that is quiet at idle, but annoying when you get on the gas. Exhaust manifold bolts can loosen or sometimes break because of the extreme heat cycles they go through and then the gaskets get burned out. You should also check the gaskets between the exhaust manifolds and the head pipes.

Steve

[PATRICKH]

Yeah, thought about manifold gasket. Hard to see up under there. I did check where head pipe joins manifold and no problems there. Is there any harm if I can't get to it right away? Its gonna be at least 3 weeks and almost 700 miles before I can work on it.

[killian96ss]

No harm, just the annoying sound which will get louder over time. Turn your stereo up a little louder until you can fix the leak!

Steve

[PATRICKH]

Already there! Thanks for info

[PATRICKH]

Ok, checked the manifold using a piece of fuel line as a stethoscope and the noise isnt coming from the manifold. There is a small metal tube on the front of the manifold and the noise seems to be coming from there. Is this part of the EGR system or Air injection? (or do we even have that on the 2001?)

[HenryJ]

EGR. Check out the information on restricting the EGR tube. That may help.

[PATRICKH]

Got ya. Checked out the posts and good info. Did closer inspection last night and there is a rubber elbow on a metal pipe right next to the manifold that is cracked. You can feel air coming out of it. Going out to replace it now... keep you posted

[HenryJ]

Are you sure it is not a rubber elbow on a hard plastic pipe? Sounds like the crankcase evacuation system?

Keep in mind that some detected a tick and thought it was an exhaust leak. I had this happen. Turned out to be the throttle cable resting on the solenoid and transferring the noise to the firewall. kinda sounded like a little kid with cards in his bike spokes. Isolating those two solved the problem.

[PATRICKH]

it could be plastic, it is definitely the source of my noise though. I put my finger over the inside of the bend and the noise stops. Didn't notice the exhaust fumes either.

[HenryJ]

That makes some sense. Easy fix too. Have you tried wrapping it with some Rescue tape? That is the silicone self sealing tape. Every truck should have a roll of that and a tube of WaterWeld.

[PATRICKH]

Didnt have the rescue tape, but did have jb weld... Curing now, not gonna start it up until tomorrow when I leave for work. I know its not a great fix, but its what I got for now.

[HenryJ]

If it works, and it should, it is a GOOD repair