top end noise
05-15-2008, 12:31 AM
#1
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top end noise my 98 trans am has a top end noise coming from what sounds like the back 2 cylinders. top end not bottom. sounded like a loose rocker arm to me. so i pulled the rockers off one of my other motors and swapped all of them over to the trans am. put in 1 piece comp push rods and the sound is still there. no broken springs or anything like that. using a stethascope you cant hear the noise through the valve cover, head, injectors, intake, headers, or anything. i tried unplugging 1 cylinder at a time and nothing changed. you can barely hear it with a load on the motor. you really hear it on de-rev or when the motor unloads. i checked the torque rating on the rocker arms to make sure i had them right. they were fine. had a few people stop by to listen to it nobody can figure it out. anybody else have an idea? im goin with a possibly collapsed lifter. any ideas are appreciated. thanks..
- Scottie
- Scottie
05-15-2008, 08:43 AM
#2
Does it come and go? I had some lifter rollers start to come apart on my car, and i could really hear it when the motor winded down. You may be able to get a little glance at the condition of the number 1,2,7 and 8 cyl lifters if you pull the intake and valley cover.