Hey all I replaced a blown header gasket and now I'm getting an erratic popping sound out of the exhaust. When I pulled the bolt on the end of the head of course a bunch of coolant Spilled Out, some of it might have spilled into the header. Could this popping noise because by leftover coolant? I open up the headers up and drove down the road for a while but I'm still getting this popping noise. What else could it be? Can anyone help?
Exhaust popping, could be coolant?
- Thread starter Valkman
- Start date
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B3422w5
Well-Known Member
Could be a plug or wire. I am sure you didnt cross wires when you took them off to replace the header gasket.
Other possibilities, bad exhaust valve, vacuum leak, running rich.......flat cam....
Other possibilities, bad exhaust valve, vacuum leak, running rich.......flat cam....
furrystump
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Header gasket is leaking air, air in the hot probably fuel rich exhaust and pop! Is it on deceleration?
It will pop erratically while at idle. It's not a backfire as much as it's a just popping sound
I just replaced the gasket. It was one of the fussy Perry gaskets. Anyone have experience with these gaskets?
BigBlockMopar
BigBlockMember
Popping usually mean a lean (idle) mixture.
As a quick test; Pinch down the PCV line when the engine is idling. Most likely the popping will be gone or at least at lot less.
As a quick test; Pinch down the PCV line when the engine is idling. Most likely the popping will be gone or at least at lot less.
harrisonm
Well-Known Member
It IS a header gasket leak, it is NOT the coolant. Never cut corners on header gaskets. There is really a reason for the price difference. Also, I HIGHLY recommend Stage 8 header bolts. They will never loosen.
furrystump
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I have had good luck with flat out graphite gaskets. I use manifolds but shouldn't matter.
d55dave
Well-Known Member
Or a vacuum leak at the intake gasket....
The Percy gaskets I got weren't cheap Percy's XX Carbon Exhaust Header Gaskets 68037 they're made of metal but they have a fuzzy foam like coating. As far other things, the car had no issues before I changed the gasket.
TrailBeast
AKA Mopars4us on Youtube
Go back and think about what you just said in that last sentence.
There isn't a chance in hell it's coolant in the pipes causing it.
I'd check them again. Get a spray bottle with water in it and spray them down with a mist after dark, start the engine and see if you have any spark jumping around.
Maybe you damaged one of the ends when removing them and don't realize it.
nm9stheham
Well-Known Member
Is that the only time it will pop? With the exhaust leak it will be like a small, muffled backfire. Is this more like metal moving and popping?
TrailBeast
AKA Mopars4us on Youtube
Checking again probably isn't a bad call, but if the only symptom is a bit of popping it's probably just fresh air getting into the exhaust.
I got to tell you this Bruce.
My Dad gave us his RV with a big block 454, and I had to go to Oklahoma to get it.
Once there he says, "Hey you might want to start that thing tonight after dark and find out where the random miss is coming from" and "I replaced the plug wire I thought was the culprit, but it still has a little random miss".
I went out and popped the engine cover off and there was 3 different kinds and colors of plug wires on it, and some looked like wrecking yard rejects.
He say's "I think it's this one pointing to one of the wires.
You should have seen the look on his face when I grabbed a whole handful of wires, ripped them out and threw them out the door onto the ground.
I went down and got new plugs, wires, cap, rotor and in cap coil button and insulator and put them all on.
He was still sticking with his story "I don't know why you did that because it was probably only that one wire".
Oh boy.
Possibly, but I'm trying to understand how air would get "in", it seems to me it would be pushing out.
He states that it pops while idling.
nm9stheham
Well-Known Member
I think folks are thinking of the slight vacuum that occurs after an exhaust pulse passes and is moving on down the pipe; the same. But I would think that is pretty much non-existent at idle. If it was coolant, though, it ought to go away pretty fast as it dried out. It the headers are still being run open the popping is normal in my experience and will continue as long as they are open.
fishy68
Tyr Fryr's Inc.
The popping may have been there before you replaced the header gasket and you couldn't hear it. Sure sounds like an erratic plug misfire to me. Mine does that whenever it's needing a fresh set of plugs. Another thing that can cause that is the timing is over advanced. It'll cause an erratic idle misfire
Ok I'm stupid, I thought I had checked the wires properly, but I had #1 & #3 crossed!! All good now.
I think I need to stop buying old cars and use my money to buy a new brain, boy I'm getting old!!!
Thanks everyone!
I thought I had checked the wires properly, but I had #1 & #3 crossed!! All good now.I think I need to stop buying old cars and use my money to buy a new brain, boy I'm getting old!!!
Thanks everyone!
fishy68
Tyr Fryr's Inc.
LOL... It's happened to most everybody sometime
nm9stheham
Well-Known Member
The only people who don't make mistakes are those who never do anything!
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