90% of the exhaust sound comes from my left foot - The 1947 - Present Chevrolet & GMC Truck Message Board Network

davepl · 08-09-2016, 01:07 PM

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

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

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

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

Quote:

Originally Posted by 70STOVEBOLT

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

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

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

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

im betting manifold too or a bad gasket

**70STOVEBOLT** · 08-11-2016, 03:26 PM

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

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??

08-09-2016, 01:07 PM	#1
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	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... __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

08-09-2016, 02:10 PM	#2
tommys72 Registered User Join Date: Jun 2012 Location: springfield mo Posts: 3,075	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 __________________ United States Marine Corps 2000-2011 Iraq and Afghanistan veteran Just living life now and enjoying it and my wife, daughter and son

08-09-2016, 02:17 PM	#3
Already Gone 70+ ( Old Skool Club ) Join Date: Nov 2003 Location: Saskatoon, Saskatchewan ,Canada Posts: 9,068	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. __________________ 1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021

08-09-2016, 03:23 PM	#4
70STOVEBOLT Senior Member Join Date: Jun 2005 Location: Winona Lake, IN Posts: 6,214	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. __________________ 70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Power windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear

08-11-2016, 01:23 PM	#6
rpmerf Registered User Join Date: Feb 2011 Location: Parkville, MD Posts: 1,024	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. __________________ 1970 C20 Custom Camper - 350, TH350 1997 GMC Suburban 1994 Acura Integra GSR 1987 Dodge Daytona Shelby Z

08-11-2016, 01:50 PM	#7
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	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! __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

08-11-2016, 02:05 PM	#8
cleszkie Registered User Join Date: Feb 2003 Location: Santa Ana, CA Posts: 2,191	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.

08-11-2016, 02:12 PM	#9
michael bustamante Senior Member Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,814	Re: 90% of the exhaust sound comes from my left foot im betting manifold too or a bad gasket __________________ 1967custom

08-11-2016, 03:26 PM	#10
70STOVEBOLT Senior Member Join Date: Jun 2005 Location: Winona Lake, IN Posts: 6,214	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. __________________ 70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Power windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear

08-11-2016, 03:48 PM	#11
NJRC10 Registered User Join Date: Apr 2016 Location: Ft.pierce. Fl Posts: 76	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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