Small "pop" in the exhaust

[lukecp]

I was running my engine (350) in park today, and around 1500-2000 rpm i hear a pop noise in the exhaust, kind of like the noise you will get when you are driving around, and let off the gas and de-accelerate. I am thinking it is a problem with the plug wires, i noticed that one of them (#3) was sitting on my headers. I proably fried it, but i want to make sure. What else could do this? Vaccum leak, distributor cap or ? The plugs, wires, cap and rotor are all about a year old.

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Lucas

"Another proud owner of one of the coolest trucks ever built"

drop_shift@hotmail.com

My Daily-Driver: '72 Chevy LWB Custom/10. Rebuilt 350, roughly 300 HP thanks to a 204/214 duration cam, Edelbrock Performer intake and 1406 carb, headers, and 40 seires Flowmaster mufflers. Ochre with a white top. Lots of fun .

[Blackhawkdc]

Wires would be on the minor side. you could also have an exhaust valve that's a little too tight. Or, parish the thought, a burnt exhaust valve. but check the wires and plugs first. Most likely you've just got a slight miss on one cylindar. Good luck man.

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Seth Petro
http://photos.yahoo.com/cowboy_55303

http://sethpetro.freewebspace.com/

1992 Chevrolet S10 4x4 "Lil' Blue"
1969 Chev C10 Stepside "Steppie"

Custom exhaust artist

[lukecp]

I was thinking that it could be an problem in the valves, but the motor was rebuilt about a year ago. Who knows though....
I haven't adjusted the valves recently. Im don't know too much about adjusting them, i heard somewhere that they don't need to be adjusted if you have hydrualic lifters? My engine has hydraulic lifters in it, so should i adust them or do they need it?

[tom hand]

A leak in the exhaust anywhere in front of the muffler can cause that.

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72 GMC Sierra SWB almost finished---- 84 Softail
Olive Branch MS



[This message has been edited by tom hand (edited May 16, 2002).]

[toms68cst]

Plug Wires! On two occasions now I've had exhaust popping and I traced it down to bad plug wires. One just had an open circuit (It was only a one year old wire!) and one was shorting out to my exhaust manifold where the wire had touched it for a long time. It's an easy fix anyway. I just replaced the bad one.

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Unrestored 68 C-10 CST. 327 4-Speed. 48,000 miles.
Bismarck, ND


See My truck and rare 1967 prototype pictures at:
http://community.webshots.com/user/toms68cst

MSN Messeger: toms68cst@hotmail.com



[This message has been edited by toms68cst (edited May 16, 2002).]

[Longhorn Man]

Place a dolar bill over the opening on the pipe that is popping. If it gets sucked in and blown out in a regular rythem, you may well have a chipped/burned/out of adjustment exhaust valve.
Once hyd lifters are set properly, you won't need to do it for a looooooong time. But eventually, they do need tightening again one day. Could be 100,000 miles, but if everything else holds up, they could end up needing it. But for all practical pourposes, that info was right.

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'69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man
I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it.
FINALLY got the HORNIAC...a '70 one ton Longhorn with a Pontiac 350/350 and lots of 'personality'. Check out The Longhorn Webite.
E-mail longhornmail@yahoo.com
My name is Andy...not Randy...I'm in Ohio...Not Illinois...close enough?
Columbus Ohio