Lt header leak?

[sumo]

this the 1st time I put lt headers on a vechile. Wondering if this is chararistic of headers. Sounds like a leak, warms up goes away. Took Stethoscope and try to listen for a leak. Took off gaskets (ones that came with headers) and inspected and no sign of leaking. Thinking of just picking up a set of oem gaskets. Anyone with headers have similar noise?

 

[drakon543]

A good set of headers should be retorqued after they are warmed up even if you are using high quality header bolts. Also unless you using arp header bolts you should also periodically return to it and recheck the bolts and make sure they haven't backed out with the heating and cooling cycles. I will listen to the video later 5 am at my house.

 

[sumo]

Yea done that torque has not changed

 

[RCYunkonDenali]

Does the sound lessen a little after the engine has warmed up a bit?
Does the sound get a louder when you accelerate? (I realize that it might not be easy to hear over the blower)

I ask, because the lifters can make a noise with LT headers that sounds like an exhaust leak. The LT Headers don't have as much sound deadening effect as the OEM Cast manifolds. So you hear more of the engine noises and the like.

The sound still makes you wonder. Mine sounds similar with the Kooks headers with no leaks that I can find. I thought it was a leak at the y-pipe, but no air there. I used OEM gaskets and nothing seems to be leaking at the head. In other cars, I've done headers on, there have been some odd noises on a few of them.

 

[sumo]

It seems like it lessens as it warms up. I had it dynoed over the weekend and the guy who did the dyno said it common with headers to sound like it has a leak but in reality there isn't one. He said the material of aftermarket is thinner that oem. So what I'm hearing is the lifters in addition to the blower. I've changed gaskets and torqued to 20 ft-lbs.
also if it was leaking it would of reflected in the A/F during the dyno.

 

[RCYunkonDenali]

Cool. Makes sense.


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[Blue 04 Z71]

Use the OEM MLS gaskets. The paper/felt ones are garbage.

 

[sumo]

Started hearing rattles from the dash, got me wondering. Went to recheck torque on blower. there are 10. the 4 corners are tight and the center 3 on each side loosened. Snug them back down until i can get my torque wrench and reset torque to 105 inch pounds. Not sure if this is the root cause, haven't started it yet

 

[sumo]

Use the OEM MLS gaskets. The paper/felt ones are garbage.

Quote from dealer driver side em gasket is 250 and pass is the same. They only stocked the drivers side.

 

[RCYunkonDenali]

It's the same part number for both Driver and passenger side. But $250 is outrageous. What part number did they give?

I got my OEM gaskets from GMPartsDirect for $11 each.

According to their catalog the Part number is the same: 12617944


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