Rattling noise from motor - 99 Acura CL
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Leroyyy
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Hey guys, I purchased a 99 Acura CL back in June, and about a month ago noticed a "rattle" developing under the hood. I figured it was my cat / heat shield / something stupid rattling, but upon further investigation I think it's a bit more serious than that.
Cliffs:
-Only happens between 1500 - 2000 RPMS
-Happens in any gear, but certain gears I'm at 1500-2000 rpms longer than others (i.e, first gear you pass 2,000 rpms pretty quick. But when I'm in 3rd gear driving down the 30pmh road next to my house, sometimes I happen to be right in that band for a decent amount of time. So the rattling continues
-Generally only happens when I'm on the throttle. When I'm not accelerating, I idle around 1,000 rpms so it doesn't do anything. And if I'm above 2,000 rpms and then drop, it will rattle real quickly but not long at all.
-It shouldn't be drivetrain related, as it doesn't happen because I turn the wheel / shift / anything else..
I've been trying to figure out what it could be. What parts of my engine only move when I accelerate / decelerate? Intake / throttle body, maybe.. Valves? Could I need a valve adjustment?
Thoughts, theories, input, advice, warnings, and anything else will be much appreciated and +rep will be handed out
I do all my own work on my Integra, rebuilding transmissions / replacing the head gasket and more, so just about anything I can do myself, so feel free to throw out some suggestions.
Cliffs:
-Only happens between 1500 - 2000 RPMS
-Happens in any gear, but certain gears I'm at 1500-2000 rpms longer than others (i.e, first gear you pass 2,000 rpms pretty quick. But when I'm in 3rd gear driving down the 30pmh road next to my house, sometimes I happen to be right in that band for a decent amount of time. So the rattling continues
-Generally only happens when I'm on the throttle. When I'm not accelerating, I idle around 1,000 rpms so it doesn't do anything. And if I'm above 2,000 rpms and then drop, it will rattle real quickly but not long at all.
-It shouldn't be drivetrain related, as it doesn't happen because I turn the wheel / shift / anything else..
I've been trying to figure out what it could be. What parts of my engine only move when I accelerate / decelerate? Intake / throttle body, maybe.. Valves? Could I need a valve adjustment?
Thoughts, theories, input, advice, warnings, and anything else will be much appreciated and +rep will be handed out
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#5
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If it rattles when you rev the engine with no load (in neutral) then get under the hood and operate the throttle cam with your hand so you can get a better picture of where it's coming from.
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Based on when it happens (at certain RPMs), its probably one of the components that is run by a belt... rollers/pulleys/tensioners/water pump on your timing belt, AC compressor/generator/ps pump/misc rollers and tensioners. Get a stethoscope or, if you dont have one, a poor man's stethoscope (something long and metallic like a screwdriver) and try to pinpoint the noise.
Also, if it hasn't been done yet, your timing belt is overdue (85k-105k miles or 7-10 years), so it's likely something on that system if it hasnt been done...
Also, check all of the motor mounts and heat shields. Could need a valve adjustment, but not likely...
let us know what you find so we can help
Also, if it hasn't been done yet, your timing belt is overdue (85k-105k miles or 7-10 years), so it's likely something on that system if it hasnt been done...
Also, check all of the motor mounts and heat shields. Could need a valve adjustment, but not likely...
let us know what you find so we can help
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Tokyosundeimasu
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06-25-2009 04:48 AM