knocking / ticking when above 2500rpm?
#1
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Car: 86 Iroc-z/ 98 Grand Prix GTP 2dr
Engine: 305...for now/ Supercharged 3800 V6
Transmission: 700R4/ 4T65E-HD
Axle/Gears: 3:23 / 2:93
knocking / ticking when above 2500rpm?
Hey everyone. I need some help trying to figure out this noise that is coming from my car. First off its more of a knock than a tick and it only does it when the engine is warmed up and past 2500rpm (gets louder the higher I rev it) but its completly silent at idle warm or cold (its around 25 degrees here in ohio). Its weird because I have no loss of power and the motor is at 60 psi when cold and at 25-30 psi when warn. The car runs perfect but I just cant figure out what this noise is. Spun bearing? Rod knock? Oil to thin? I was also late doing my motor break in oil change . I have no idea what it is though. The motor is coming out this winter and getting vortec heads, xe268 cam, and full exhaust, but I would like to use this motor because its a 355 with forged internals and it would be nice to use this block. But if not i'll start looking for a 400ci short block to put my upgades on. Any ideas/input is really appreciated . Thanks guys.
Last edited by Drew86maro; 12-24-2009 at 06:01 PM. Reason: more info
#2
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Car: 86 Iroc-z/ 98 Grand Prix GTP 2dr
Engine: 305...for now/ Supercharged 3800 V6
Transmission: 700R4/ 4T65E-HD
Axle/Gears: 3:23 / 2:93
Re: knocking / ticking when above 2500rpm?
No ideas? Merry christmas everyone
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Car: 84 Camaro Z28
Engine: 355 Carb
Transmission: T5
Axle/Gears: 3.42
Re: knocking / ticking when above 2500rpm?
I had a problem similar to yours in which my engine was making a knocking noise at high rpm and no noise at idle. When I tracked down the problem I found out that one of my rocker was loose and was causing the noise.
I hope you find on what's wrong with your car
I hope you find on what's wrong with your car
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Car: 91 B4C "police special service"
Engine: L98 494hp
Transmission: tko-600 on order
Axle/Gears: 3.23 true trac
Re: knocking / ticking when above 2500rpm?
sounds like a rod knock to me. Could be anything though, you might have to recheck clearances. I had a nova that did that same thing, except at about 3k rpm. merry xmas.
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Car: 86' Z28
Engine: 350
Transmission: 700r4
Axle/Gears: 2.73 (for now)
Re: knocking / ticking when above 2500rpm?
That would be my guess.
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Car: 91 B4C "police special service"
Engine: L98 494hp
Transmission: tko-600 on order
Axle/Gears: 3.23 true trac
Re: knocking / ticking when above 2500rpm?
It's hard to diagnose sound over the interet, but I would check everything before running it anymore. If it is a bearing, parts may be able to be saved, but running it more could damage beyond repair.....good luck.
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#8
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Car: 86 Iroc-z/ 98 Grand Prix GTP 2dr
Engine: 305...for now/ Supercharged 3800 V6
Transmission: 700R4/ 4T65E-HD
Axle/Gears: 3:23 / 2:93
Re: knocking / ticking when above 2500rpm?
I never thought about that, . Im going to look into it some time today if I have time. And if it is a rod knock then I wont be driving it so I dont damage it any farther. Thanks for all of your responces guys.
#9
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Car: 86 Iroc-z/ 98 Grand Prix GTP 2dr
Engine: 305...for now/ Supercharged 3800 V6
Transmission: 700R4/ 4T65E-HD
Axle/Gears: 3:23 / 2:93
Re: knocking / ticking when above 2500rpm?
Ok, im 95% sure its a bottom end noise (bearings) so my options have changed. As of right now it isnt bad enough to have damaged anything so im gonna replace the bearings (if crank/rods are ok) when the motor comes out to put the vortecs on. If worst comes to worst and there is more damage than expected them im just going to buy a decent 383 kit insted of a 400ci block. .
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