Can't get rid of this exhaust leak!!

I have an exhaust leak at the manifolds and I just can't get rid of it. I tried 4 different gaskets and no luck. I even tried doubling up and it was the best i've gotten it so far. In my last attempt, I made sure to scrape off all the old gasket(s) and use a fresh set of lock washers. Now it leaks even worse. I think maybe my manifolds aren't straight? Or should I try tripling up on gaskets? I've been told that you can get away with no gaskets with manifolds. What can I do?

 

Can you pinpoint the location?

 

Manifolds may be warped, you can check them with a straight edge next time u have them off...

What engine/manifolds are you running?

 

What type of motor and manifolds do you have? (fifty2 beat me to the question)

 

Live with it?

Sorry I haven't been an ass yet today and you were available.

I am not sure what you are working with, but you can lat a straight edge across the manifolds and see if they are straight, if not you can have them faced.

Or something that I have done with good sucess is use Permatex Silicone with copper in it. It holds up to the heat real well. This obvoiusly not the high tech way to cure the problem but it wirks. I still use gaskets when I do this and I give it some time to cure before lighting it off.

 

I can't pinpoint it, it only really does it under load. I'm running a 350 with ceramic-coated manifolds

 

I had a one the other day I couldn't find at the header. ended up being a hairline crack on the flange . Now its nice and quiet!

 

Take a 3 foot piece of air hose or 3/8" fuel hose, hold one end to your ear with the engine running and run the other end around any joint, gasket or bolt. You will find it when you get close and then you can figure out why it is leaking and correct the problem. Don't forget to come up from underneath.

 

Ceramic coated manifolds, as in ceramic coated headers made from tubing or manifolds as in cast iron factory pieces that you have ceramic coated.

 

Take the manifold off and get it surfaced......

 

They're cast manifolds, not tube headers. I'll try the "stethoscope" trick but maybe this is an excuse to buy the headers I've had my eye on!

 

if it isnt to much and too hard to find i would replace the manifolds. sounds like they are the problem.

 

Napa sells a product make by walker part# 35959 exhaust cement put it on both sides of the gasket like sealer. I used it on a manifold and head that had leaked so long it had eroded. It's been years and it's still OK.

 

Thanks for the info. I have a ford FE with a manifold leak.

 

had the same problem turned out to be a crack flex plate

 

I have fixed trickt exhaust leaks with copper gaskets in the past. Headders and manifolds. They arn't cheap but neither is 4 sets of regular gaskets.

 

I use remflex on my FE's and they handsdown work! Even had a set warrentied without anyproblems.

Check the manifolds for straightness, smooth them out if need be and try out some remflexes.

Also If you cant pinpoint the leak, seafoam ur engine. When you start it up it will puff white smoke from the leak.

 

Chevy did not use gaskets on the manifolds on 350s.

 

Ha, Ha.

I had a ticking lifter that I chased for a month and it turned out to be a leaking header flange/gasket.

 

yeah, I was gonna suggest checking the valves!

 

Turn the radio up a little louder,that works for all the little noises I dont want to hear.

 

I have had real good luck with regular gaskets and high heat copper permatex. Never a leak.

 

Yep...
And, i've run MANY with nothing more than high temp black permatex as "gaskets".
Apply a normal amount to the manifolds then bolt em on. start it to let it heat up then shut off to cool. Snug up the bolts for good measure and you're done..
That is providing the manifolds are not warped. If yours are, have them surfaced as was mentioned and give this a try. You may be surprised.
I even did the manifolds on my 62 Impala 409 that way..NO leaks.

Tony

 

I never use gaskets or sealer on Chevy V8s with manifolds, and they don't leak. but I use old used parts, not fancy plated stuff.

 

I have used Remflex gaskets where other gaskets would not seal and have been pleased with them.

www.remflex.com

 

What he said.........

 

No radio

Already checked the valves haha

I definitely think the manifolds are warped, because after this many sets of gaskets there's obviously a problem somewhere, right? So if they are, how much and where can I get them resurfaced? I mean, I could find a decent pair of tubes cheap from Summit anyway

 

By the time you get the manifolds surfaced your most likely gonna be half way dollar wise into some headers... so if youve been eye ballin em you might as well buy em and call it a day!! just my 2 cents...

 

Years ago I had a truck with a 454 that had warped manifolds. They were REALLY warped and there was just no way to seal them up. A guy suggested "Ultra copper" silicone. I told him "you don't understand, the manifolds are warped, it's leaking where the manifold bolts to the head". He said "yup, I know, use the silicone". I thought he was retarded to even THINK that silicone would stand the heat ESPECIALLY since the truck was running on propane which creates higher exhaust temps than gas. Out of desperation, I tried the silicone and, wouldn't ya know, IT WORKED and these manifolds weren't just warped a little, they were warped alot.

 

I had a bad leak and went through 2 sets of gaskets...different brands too. Took them out and spanked the ram horns right on the port and no leaks. Horns are silver and don't see any marks from the exhaust.