strange knock/rattle from ls6 on engine decell??
11-13-2010, 09:15 AM
#1
Burning Brakes
Thread Starter
strange knock/rattle from ls6 on engine decell??
driving the car last nite i noticed a sound i have never herd before. . . car is a 02 Z06 39k miles. . if the motor revs to 3k or higher on the decell back to idle it makes a noise. . it kind of between a rattle/knock sound. . . if the motor stays under 3k revs, its quiet like normal, idle's fine all quiet. . . it is a cam car, cam was installed by myself 4k miles ago. i pulled both valve covers and pulled the rockers, checked the push rods, and the dual valve springs, all ok. . . i pulled off the accessory belt and started it too to make sure it was not a water pump/idle pully/PS pump, etc.. still made the noise.... my next thought are lifters, which are new LS7's done during the cam swap, or something in the timing gear, or maybe a valve tap/bent valve. cam is a 232/236 duration- 595/605 lift stock 243 heads. . . . looking for a litte advise if anyone has seen this type of noise and remedy before.. thanks, phil
Last edited by MX621; 11-13-2010 at 09:29 AM.
11-13-2010, 10:48 AM
#2
Burning Brakes
I get a sort of deep vibration exactly between 3200-3000 RPM when winding down, in any gear.
It's happened since I installed a full Z06 exhaust system on my 2000.
I assume it's the exhaust, hasn't changed in 5 years. It's kinda like the engine or the pipes resonate at that particular RPM.
May not be what you are hearing, but I thought I'd mention it.
DG
It's happened since I installed a full Z06 exhaust system on my 2000.
I assume it's the exhaust, hasn't changed in 5 years. It's kinda like the engine or the pipes resonate at that particular RPM.
May not be what you are hearing, but I thought I'd mention it.
DG
11-13-2010, 11:23 AM
#3
Burning Brakes
Thread Starter
sounds like ur talking about the exhaust "jingle" from the factory Hpipe on the ZO6 exhaust, lol . . . . im doing a compression test to determine if any P2V contact has been made resulting in a bent valve. . . well see
11-14-2010, 03:04 PM
#4
Burning Brakes
Thread Starter
compression test was 190 all 8 cylinders, leads me belive that the valve's are seating properly and not bent, i know a leak down would have been better but i dont have one. . . not sure y the tick/knock/rattle would only make the sound on de-accell of the motor and not during idle or engine accell. . idk....
11-15-2010, 12:43 AM
#7
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