pipe popping

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inertia, you are the second guy to tell me that. Maaan I hate to pull heads.

What do you think of my leakdown numbers?
 
well if one valve is sticking this should mean that there should be a temp difference between the cyclenders try getting a spray bottle with some water in it spray it on the headers the one that show the least amout of evaporation is the one with the stuck valve
 
With the compression test you are good.
Your leak down tester is junk.
I have the same one from summit, it is ok at best.
The motor runs hard and great?
Why tear it apart, my bet is still on your exhaust does not seal until it gets hot.
Post a video of what it is doing.

My 78 power wagon has some welded up exhaust patch in it.
I made sure it was good and hot when I went to the inspection station because it was quiet when hot.
 
I'm in the exhaust camp too. Have you tried with a helper, blocking the tailpipes to see if anything shows? With a cam like that engine would have, it'll make the headers ring enough that it would be a little hard to detect otherwise. I think i'd get in touch with Brian for any input he may have before pulling the engine apart. Hey. it's just a phone call :D.
 
You said it ain't the plugs, but we had the same problem years ago in a Challenger 340 car my brother owned. Did the same thing you're doing now...went through everything, still popped. Turned out to be a cracked insulator on one of the plugs causing erratic firing, and igniting the unburned gas in the exhaust system.

I agree with the poster who mentioned pulling one plug wire at a time, if it stops, I would concentrate on that cylinder, and replace the plug first!! Geof
 
Not plugs. Brand new. Wires too(Firecore). I'm thinkin its gotta be exhaust. Don't think it can be too far downstream to cause the popping. I guess it has to be at the header flange....maybe the collector.

Somehow I get the feeling I'll be pulling the heads eventually........sure hope not.
 
My duster just started doing the same thing. it was so embarrassing I drove it to the last three shows with open headers.. I replaced the left side gaskets adapter to head and header to adapter. Didn't help. what I found was a cracked header. number 5 tube.
 
Ironmike said:
Not plugs. Brand new. Wires too(Firecore). I'm thinkin its gotta be exhaust. Don't think it can be too far downstream to cause the popping. I guess it has to be at the header flange....maybe the collector.

Somehow I get the feeling I'll be pulling the heads eventually........sure hope not.
Click to expand...

I was really annoyed with mine, but I'm betting you're in the same boat, bad exhaust valve somewhere.
 
finally got the time to dig into this issue and was hoping to find an answer but not sure. Definitely number 7 causing the popping. All cyls exhaust temp within a hundred degrees or so. Popping still fades away when thoroughly warmed up. So...

Off come the Dougs headers(jeez). Was really hoping to find a crack at #7 pipe and did not. All I found was a leak at the collector, which I'm not sure would cause the "venturi" effect popping noise. Could not hear or feel the leak when the thing was running. The header gaskets came off in pieces, of course. Don't THINK there was an issue there.

Here's my question to you guys:

Before I button this thing all together again, should I pull the heads and have them checked since access is there now(headers off)?

As most of you guys thought, I still feel it was an exhaust leak. I can't believe the Indy RHS heads, Ferrea valves.....all done by Brian....could have an issue with only 3000 miles.......and go away after it warms up.

What say you, guys? Pull the heads or throw on my new TTI's and run it.

Really appreciate all the help.
 
Maybe just bolt the old headers back up with a new gasket and see if it stops. If cold air is getting at the valve thru a crack somewhere your troubles could increase.
 
Just bolting up the headers in this car is a big deal. Z bar hassles along with starter. you need 5 hands......That;s why I ordered the TTI's. Hear they're a much easier install on a 4 spd car.

I've ALMOST convinced myself to pull the heads for peace of mind.
No hissing coming thru exhaust at leakdown, though.
 
If it was in my shop and I had not found the "smoking gun" yet I'd pull the head even if Reher Morrison built it. I will add that exhaust popping is from oxygen and unburnt fuel getting into the headers. Either from a weak cylinder (i.e. weak ignition, poor rings, burnt/hanging/bad valve, or a gasket leak. Your cylinder pressure is good but it does nto tell you that much other than the cylinder is sealed well enough to spike the gage. The leakdown is more than likely a bad gage or not enough volume/pressure in the compressor. I own the Moroso and if there's not 110psi or more it can be inaccurate. If the pop isn't bad at idle but gets worse I'd say it's more than likely an exhaust related issue. But you didn't find a bad gasket or header issue and that would have been my #1 thought. If the #7 plug looks like the others on that side then I'd pull the head just to peak. It can't hurt and the cruddy part's already done to get it off.
 
I'm thinkin' just like you. Darn thing doesn't pop at all at idle, but no smoking gun...
 
I had the same issue on a 73 charger that i owned years ago...it turned out to be header gasket leak. Try a pair of Remflex gaskets, they are reusable and won't stick or burn out.
 
Checked the headers with a magnifying glass, they look fine.......gaskets came apart upon removal. Did find a collector leak. Like I said, couldn't hear or feel a leak anywhere right before I tore the headers off. This is frustrating.

I think a weak ignition would cause issues on more than 1 cyl, wouldn't it?
 
Do the Exh port on the head look even, aka color texture exc. Can you get a mirror and actually look at the exh valve and seat area.

If i couldn't find any difference between #7 and 1,3,5 I would NOT pull the head!

Did you look at all the welds?... collector or defuser (Sp) weld.

Maybe bolt a block of wood to the header ports and then another one over the outlet of the header/collector. Then, drill a small hole in it and install a air fitting. then just add air pressure to see if you have a leak any were

YOUR LEAK DOWN TESTER WOULD BE IDEAL FOR THIS TEST. As you could regulate the pressure in the header.

4 feet of a 2x4 and drill bit and some nuts and bolts would get the job done.

Way less time then pulling a HEAD.........
 
OK. Exhaust ports all look the same. I DID find a leak at the collector but I'm thinkin' that's too far downstream to cause the popping. Ya think that could be the problem?

Like I said, I reeeeally don't wanna pull the heads unless I have to.
 
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