Mechanics

CHEVROLET CAVALIER RPM PROBLEM

2000 Chevrolet Cavalier • 173,000 miles

When car is idiling it is fine with just a little noise and then when you accelerate motor past 2000 rps motor starts getting a tapping sound and then gets a louder as you go up in rpms but does not get louder when you let off. So I dont think it is bottom end noise. What do you think. I am really hoping it is a lifter.
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Cjh586
January 15, 2013.




Lifters will make more of a tapping sound and bearing will knock. Can you tell the difference on your car? If you put it in gear with your foot on the brake and slightly give it gas, does the sound get worse or change?

At 2500 rpms in neutral loud ticking but I when I put it in gear and held brake and brought it to 2500 rpms wasnt as loud.

Tiny
Cjh586
Jan 15, 2013.
That leads me to believe it is a rod or main bearing. When you put the load on the engine, it wasn't as bad. A lifter won't change if there is a load on the engine.

When I am driving it is as loud as it is in nuetral. I know that for sure. Thats what I didnt uderstand when I held the brake and accelerated. Maybe I couldnt hear it as much because of the breaks locking up while I held it down. I know I can def hear it going down the road from inside the car. When it finnaly shifts into overdrive about 65 I cant really hear it no more at all if you ease into the throttle around 2500 rpms. So if it is the same or a little louder what do you think it may be.

Tiny
Cjh586
Jan 15, 2013.
That is a good question. It could even be a cracked flywheel
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So pretty much a loud tapping noise is ussually top end and a loud knocking is bottom end? Taking the vavle cover off a good place to start? I have to change valve cover anyways cause of a small crack. And if so what should I look for? Thank you so mich for your help

Tiny
Cjh586
Jan 15, 2013.
I think that would be a good place to start. Check to see if any if the rocker arms are loose.

Let me know what you fund.

Joe


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