Ramairbird

iTrader: (17)

I've had these LT's on my car since I did the H&C on my LS1 back in 2006.Now there on my LS3 swap that is in year 2. I tend to hear a noise mostly from under the engine area when it is idling that sounds like valvetrain noise but is exactly the same from my LS1 to the LS3. If the car is idling and you stand next to it or sit in it it can be heard. On both engines I had rechecked my push rod selection and geometry only find it was ok. I'm starting to think this is not valve train noise but header noise from the exhaust pulses. There are no exhaust leaks and no cracks. I like the headers, they are well made and have been trouble free. I run high flow cats behind them to a dynatech y. Just wondering if this is something these lt's do. Thanks.

libertyforall1776

iTrader: (2)

Try an automotive stethoscope to help isolate the noise -- Harbor Freight sells them cheap.

Ramairbird

iTrader: (17)

That's a good idea, I have one at work.

The_Bishop

iTrader: (10)

I had a ringing in the used Dynatech headers I installed, thought it was the tubes ringing against each other. Careful examination revealed a header bolt lodged in where the 4 tubes come together. A little pry bar pressure and magnet fishing, problem solved.