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-   -   90% of the exhaust sound comes from my left foot (https://67-72chevytrucks.com/vboard/showthread.php?t=714635)

davepl 08-09-2016 01:07 PM

90% of the exhaust sound comes from my left foot
 
This is hard to explain. I don't have an exhaust leak, though at first I thought I might.

I get a loud ticking sound from the downpipe on the driver's side. So the pipe that comes off the manifold seems really loud, like someome is ticking away at it in time with a screwdriver, but it's not a mechanical hit, almost a sympathetic ring.

On the one hand it sounds like others of these trucks I've had, probably because they all (V8) have that exhaust pipe there.

Are the big blocks perhaps worse? With a big block and cast iron manifolds I was hoping for more of a "blub blub blub" low factory exhaust note, but I might as well be running headers for the ticking!

I am 95% sure it's not a mechanical problem, like a loose rocker, though anything is possible. I just think it might be how these things sound, but I don't have access to another big block to listen to.

If it's a "known characteristic" I'm hoping maybe someone has found a solution, like wrapping that part of the exhaust pipe with thermal wrap or some insulation...

tommys72 08-09-2016 02:10 PM

Re: 90% of the exhaust sound comes from my left foot
 
im intersted to see answers on this too. I have a 350, but have a tick too. No exhaust leak (just passed inspection not long ago) no loose rocker on drivers side. But i have a horrible tick out of the drivers side. Always wondered what it was

Already Gone 08-09-2016 02:17 PM

Re: 90% of the exhaust sound comes from my left foot
 
I just had some work done on mine ( stock 350 with rams horns ) and my tech guy said the same thing. You have a little leak up front on drivers side. It'll be interesting to se if anyone has an answer to this.

70STOVEBOLT 08-09-2016 03:23 PM

Re: 90% of the exhaust sound comes from my left foot
 
Are you sure the exhaust manifold is not cracked somewhere that you can't see, like on the side that faces the block? The exhaust manifolds are prone to cracking on the big blocks. I was looking for a LH manifold to replace the cracked one I have a while back and every OEM manifold I found was cracked. The RH side does not seem to have this problem. My theory on that is the way the manifold is shaped and where the outlet is.

Valarius_Starchaser 08-09-2016 03:26 PM

Re: 90% of the exhaust sound comes from my left foot
 
Quote:

Originally Posted by 70STOVEBOLT (Post 7678326)
Are you sure the exhaust manifold is not cracked somewhere that you can't see, like on the side that faces the block? The exhaust manifolds are prone to cracking on the big blocks. I was looking for a LH manifold to replace the cracked one I have a while back and every OEM manifold I found was cracked. The RH side does not seem to have this problem. My theory on that is the way the manifold is shaped and where the outlet is.

My vote goes to this but I'm along for the answer

rpmerf 08-11-2016 01:23 PM

Re: 90% of the exhaust sound comes from my left foot
 
Could you put on a stethoscope and try to find where the sound is coming from? If you don't have a stethoscope, you can put an earplug in one ear, put a vacuum tube up to your other ear, and use the tube to find the source of the sound. Be sure to check around the exhaust ports and exhaust donut.

davepl 08-11-2016 01:50 PM

Re: 90% of the exhaust sound comes from my left foot
 
I'll give it a shot with a tube stethoscope and see if there's a "point" it's coming from or not. Thanks for the tips!

cleszkie 08-11-2016 02:05 PM

Re: 90% of the exhaust sound comes from my left foot
 
I have a 400 SBC with 2.5" ramhorn manifolds. The only time I get a tick of any sort is when a donut gasket is going out. That is my vote.

michael bustamante 08-11-2016 02:12 PM

Re: 90% of the exhaust sound comes from my left foot
 
im betting manifold too or a bad gasket

70STOVEBOLT 08-11-2016 03:26 PM

Re: 90% of the exhaust sound comes from my left foot
 
If the donut is blown out and it's a fiber type I would replace them both with the sintered metal type. The manifold and exhaust pipe mating surfaces have to be pretty good to get a good seal on that type but they WILL NOT blow out. Let us know the outcome.

NJRC10 08-11-2016 03:48 PM

Re: 90% of the exhaust sound comes from my left foot
 
Mine has a tick as well ( zz3 with stock ram horns ) but we know it is a lifter that won't stay pumped up on the drivers side of my engine. It starts out pretty loud then quiets down as I run it. I want to add some lucus to see if it helps??


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