Exhaust leak
Thread Starter
Race Director
Joined: Oct 2019
Posts: 10,735
Likes: 63
From: Deep in the Pisgah National Forest
Exhaust leak
A week ago I was driving and noticed noise coming from the engine compartment. Exhaust leak on the passenger side, near the header I think. Today I got around to lifting the car (floor jack) and inspecting- didn't find a thing. I drove it again today a short distance, the noise is worse, now. Seems to be both sides now, passenger side worse.
Original "stainless" headers, air tubes sealed. Not leaking at the tubes. "Barn find" car, about 40k miles, been driving it 20 miles/ month for two years.
I'm guessing that the head-to-header gaskets just gave up, both at more of less the same time.
Headers don't last forever. I'm thinking of these: https://pertronixbrands.com/products...31797117976612
I've already redone the exhaust, removed the cat and have an actual dual with new stainless tips. I'm hoping for a bolt-on.
Any suggestions will be appreciated.
Original "stainless" headers, air tubes sealed. Not leaking at the tubes. "Barn find" car, about 40k miles, been driving it 20 miles/ month for two years.
I'm guessing that the head-to-header gaskets just gave up, both at more of less the same time.
Headers don't last forever. I'm thinking of these: https://pertronixbrands.com/products...31797117976612
I've already redone the exhaust, removed the cat and have an actual dual with new stainless tips. I'm hoping for a bolt-on.
Any suggestions will be appreciated.
Race Director
Joined: Nov 2006
Posts: 13,254
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
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Cruise-In VIII Veteran
Suggestion, As this is hard to fix if one is not there. Perhaps start car, open hood and listen, look. try to see if it is indeed the head to header gaskets. Perhaps check to see if the bolts are tight.
NCM Grand Opening Veteran
Joined: Sep 2005
Posts: 20,979
Likes: 384
From: South of giving a damn
St. Jude Donor '11, '17
Yad - forget the cheap headers, I've seen you in ot - you have the cash. Buy Dougs & have them coated. Don't futz around with cheap, cheap always costs more in the long run.
Thread Starter
Race Director
Joined: Oct 2019
Posts: 10,735
Likes: 63
From: Deep in the Pisgah National Forest
Shiny new headers would complete the clean look under the hood that I'm going for, so that's another advantage.
Thread Starter
Race Director
Joined: Oct 2019
Posts: 10,735
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From: Deep in the Pisgah National Forest
The link is to coated headers that are supposedly a stock replacement.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
I would hardly call $400 headers cheap. Cheap would be flat black, non-ceramic for $199.95 or less.
Yadkin,
The flange on your headers may have warped causing the leaks you hear. There are two ways to fix this w/o complete removal.
Remove all bolts on one header only.
Remove old gasket material.
Using a hacksaw blade with no handle, cut a kerf on the backside of the flange. A kerf is about an 1/8" deep cut.
This kerf should go between cyl 1 & 3, between 5 & 7.
Then between 2 & 4 and between 6 & 8.
That kerf will allow the flange to flex ever so slightly and seal better to the head.
I recommend a soft metal gasket such as copper or aluminum. Those have a lot of give and will fill in imperfections of the flange.
Percy has an excellent pair. Pricey, but work like a charm and can be used over & over. You should be able to slip those in place.
Then always torque header bolts from the center outward, in two or three torqueing steps.
Yadkin,
The flange on your headers may have warped causing the leaks you hear. There are two ways to fix this w/o complete removal.
Remove all bolts on one header only.
Remove old gasket material.
Using a hacksaw blade with no handle, cut a kerf on the backside of the flange. A kerf is about an 1/8" deep cut.
This kerf should go between cyl 1 & 3, between 5 & 7.
Then between 2 & 4 and between 6 & 8.
That kerf will allow the flange to flex ever so slightly and seal better to the head.
I recommend a soft metal gasket such as copper or aluminum. Those have a lot of give and will fill in imperfections of the flange.
Percy has an excellent pair. Pricey, but work like a charm and can be used over & over. You should be able to slip those in place.
Then always torque header bolts from the center outward, in two or three torqueing steps.
Last edited by HeadsU.P.; Oct 11, 2021 at 01:07 PM.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
The link for the headers you posted is for 3/4 length.......more difficult to hook up to exhaust at the muffler shop..... Buy a quality ceramic coated long tube set for your car......from Hedman, Doug's, Hooker.......etc.....
Jebby
Last edited by Jebbysan; Oct 12, 2021 at 10:36 AM.
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Thread Starter
Race Director
Joined: Oct 2019
Posts: 10,735
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From: Deep in the Pisgah National Forest
No those are the ones that I ordered. The reviews for the uncoated include comments that they fit well in a C3.
I'm going to have the same shop that did the cat and y-pipe conversion to true dual with X-pipe install these.
I'm going to have the same shop that did the cat and y-pipe conversion to true dual with X-pipe install these.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
I double checked that part number. You are correct.
I just don't see how headers that fit a '55 Chevy or a Chevy station wagon can fit your C3.
The drivers side unit looks like it will not clear the frame near the oil filter protrusion, but time will tell.
And Dougs headers are another $200, getting close to seven bills. I agree, overkill on a stock C3.
I just don't see how headers that fit a '55 Chevy or a Chevy station wagon can fit your C3.
The drivers side unit looks like it will not clear the frame near the oil filter protrusion, but time will tell.
And Dougs headers are another $200, getting close to seven bills. I agree, overkill on a stock C3.
Thread Starter
Race Director
Joined: Oct 2019
Posts: 10,735
Likes: 63
From: Deep in the Pisgah National Forest
I double checked that part number. You are correct.
I just don't see how headers that fit a '55 Chevy or a Chevy station wagon can fit your C3.
The drivers side unit looks like it will not clear the frame near the oil filter protrusion, but time will tell.
And Dougs headers are another $200, getting close to seven bills. I agree, overkill on a stock C3.
I just don't see how headers that fit a '55 Chevy or a Chevy station wagon can fit your C3.
The drivers side unit looks like it will not clear the frame near the oil filter protrusion, but time will tell.
And Dougs headers are another $200, getting close to seven bills. I agree, overkill on a stock C3.
Thread Starter
Race Director
Joined: Oct 2019
Posts: 10,735
Likes: 63
From: Deep in the Pisgah National Forest
The headers came in and I had a local shop put them in. As I suspected they are NOT a stock replacement. The angles work out and they do fit, but required a short list of modifications:
- Re-route heater hoses for clearance
- Cut and shorten the engine pipes, including moving the O2 sensor.
- The tubes are bigger so the brand new heat shields that I installed last year had to come off.
- "Header" spark plugs that are slightly shorter.
Race Director
Joined: Nov 2006
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Sounds like pretty normal fare when installing headers. Seems they fit. Good onya!
Safety Car
Joined: May 2001
Posts: 4,759
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From: Fairfax Virginia
I would have suggested using some of the Soft aluminum or Soft Copper exhaust gaskets as they are really long lasting. I have a set that is over 25 years old still behind the Long tube headers and I have never had to re-torque the headers.