Moparts Tech Archive

Exhaust

Exhaust Seaking & Leaks

71ChargerSE440CI
Moparts Member
Posts: 4480
From: Rancho Cucamonga, So. California, USA
Registered: May 2001
posted 01-19-2003 12:39 AM

Heard a tapping/clicking noise today after making a 20-minute trip on the freeway (3,500-RPM at 75-MPH with 4.10 gears).
I also worked on the exhaust a few days ago, without removing the pipes, etc from the car (welded new mufflers on in-place.) The Header gaskets are 6-months old, headers are TTI 2-inch primary tubes.

Not sure if the noise I hear is valvetrain noise from the moderate/high sustained RPM or an exhaust leak(s) due to the weight of the new exhaust/disturbance of the system.

I DO have hangers for the exhaust, but who knows.

Any way to tell which it is (exhaust or valvetrain) before I buy new gaskets?

I tightened/re-tightened the header bolts and added 1/2-Quart of Marvel Mystery Oil to the crankcase to (I hope) quiet any noisy lifters.

The valvetrain consists of 292/.510 Hyd Cam, Chrome/Moly Pushrods, HD Stamped-Steel Rocker Arms and the heads/Valves/Springs are around a year or so (low milage, infrequently driven) old

Any way to tell the difference?
The clicking/tapping seems to speed-up/keep-pace-with RPM increase.

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mulutchoker
Moparts Member
Posts: 306
From: bonitasprings fl. usa
Registered: May 2001
posted 01-19-2003 12:56 AM

i can tell the diff . but only from experience, if you want to check here are a couple of back yard ideas, take a thick towel and cover your valve covers if it dosent muffle the noise that aint it. or alittle messsssssssier way is spray some wd 40 on the ex. man where it meets the head and listen for a slight muffled sound.

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moparmarv
Moparts Member
Posts: 203
From: Oak lawn IL
Registered: Sep 2002
posted 01-19-2003 01:00 AM

They sound almost the same. my buddy had a cherokee and it was making a clicking sound. we both though for sure it was the valve train. it turned out the exhaust manifold was cracked.

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beeper71
New Member
Posts: 96
From: wisconsin
Registered: Jan 2003
posted 01-19-2003 01:02 AM

Hard to tell difference, Try starting cold engine use fingers to check for leaks around headers before exhaust gets to hot,BE CAREFULL may have to let it cool and try more than once. If sticky lifter change oil and substitute 1 quart tranny fluid with oil,high detergent in tranny fluid will free most sticky lifters.

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73Chargerkid
Moparts Member
Posts: 2290
From: San Marcos, CA
Registered: Jan 2001
posted 01-19-2003 01:05 AM

I have many with my crappy heddman headers so i'm pretty good at telling the difference. Sometimes depending on where the leak is, it will get louder when you get on the throttle, like someone stuck a piece of paper over your exhaust.
You could bring it down here and gimme a ride and I'll tell ya, or better yet i'll take it for a drive!

what I was hearing was more of a sewing machine sound, like a solid lifter cam that needed adjustment, but it could of been piston skirt slap like you said. If you're hearing a ticking it could be exhaust, it could have been there for a while you just couldn't hear it over the old setup

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Vantravlrs
Moparts Member
Posts: 105
From: Nashville, NC, USA
Registered: Apr 2002
posted 01-19-2003 02:02 AM

Double up the header gaskets. They only run 10 bucks a pair. Ive had OK luck with Mr . Gasket header gaskets, and only fair luck with the Fel Pros.
The easy way to check for leaks (at least this is how I do it) around the headers is to run it for a while, and then look for carbon deposits on the silvery side of the gaskets where they aren't behind a tube.
As far as ticks on the inside of the engine... take a stethicscope and listen to the valve covers while the engine is running! (seriously).

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mopar _man
Moparts Member
Posts: 683
From: Newfoundland Canada
Registered: Dec 2001
posted 01-19-2003 08:45 AM

Its hard to detect a leak with the stets. the easiest way is to get a piece of 3/8 rubber gas line 3 or 4 ft long . put one end to your ear and feel around with the other end around the header. if you have a leak , you will diffinately find it.

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383-man
Moparts Member
Posts: 6021
From: Balt. Md. USA
Registered: Nov 2000
posted 01-19-2003 10:02 AM

Right on mopar_man. I actually have a set of doctors ears (stethoscope) for noises and I use just the hose part like mopar_man said for exh leaks and you will know when you find the exh leak. Ron

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