C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Need Help Please Look!!!!!

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Old 09-30-2007, 09:22 PM
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kowalski340
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I have a 1989 L98 with 113,000 miles and even before I bought it it had a moderate ticking sound I attributed the sound to some top end noise......now I am very nervous as I am getting ready for a trip to SEMA and I need to figure out how to figure what the noise is coming from. I was thinking perhaps lifter noise or some sort of valvetrain clatter also perhaps injectors? I am seriously hoping that this is not a serious knock.....it doesn't really sound like it thank god! the sound increases not in volume but goes faster when it is revved. should I pull the valve covers and then the intake and see what condition the valve train is in first or go straight for the motor pull and start the tear down. keep in mind that I don't really have the budget for a full build right now and would like to create a stop-gap for a month or so until I can fix it properly. The sound appears to be coming from the top end.........very wierd thanks in advance! Also I have good oil pressure 45-48psi at 800-1000 rpm and the motor runs fine.

Last edited by kowalski340; 09-30-2007 at 09:24 PM.
Old 09-30-2007, 09:29 PM
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jpobrien
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I have Ford Racing injectors that make a lot of noise (sounds like a valve tick). If you can put a long screwdriver against one of the injectors and the handle against your ear (while the car is running), that will magnify any sound coming from the injectors and you should be able to tell if that is it.

Last year, I had some sort of knock/tick, that ended up being a bad rod bearing. Found that out on the track at high rpm.
Old 09-30-2007, 09:43 PM
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Sam Lam
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In reading your thread, it sound like a worn out hydraulic valve lifter or that it is out of adjustment. Using a long screwdriver (and be very careful doing this) see if you can find which side of the engine the sound is originating. You can easily find the side of the engine with the problem and you may be able to find the problem cylinder.
Old 09-30-2007, 09:57 PM
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engle1147
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I hold off on the tear down just yet.....from what your describing it sounds more like the "standard" fuel injector tick noise to me if the sound gets faster but not louder.....find somebody with the same year 'vette and get them to give you a listen under the hood and see if the sounds are similar. If the "tick" noise has stayed the same and not progressively gotten louder over the time since you bought the car 'til now then it stands to reason that it will go a few more miles with no additional problems.

Old 09-30-2007, 09:58 PM
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Demonic85
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I'd pull the valve covers and see if the rockers are loose, mine make that noise when lose. Oh and see if you've got at least 40 psi of oil pressure. A loss of oil pressure could result in the oil not reaching the top end and then you hear metal on metal.
Old 09-30-2007, 11:01 PM
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kowalski340
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thanks for all your help i'll try some of your suggestions.......what happens when I find what side it's coming from?
Old 09-30-2007, 11:58 PM
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vinnies87
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That depends on what you find.... wrong.... hard to say how to fix something if you don't know the problem...
Old 10-01-2007, 12:19 AM
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Bobwhite85
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I have an 85 and it had a ticking noise when i got it, DROVE ME NUTS! Car ran good to! Didn't get louder with RPM but did speed up some, turned out it was injectors, nothing wrong with them but when I did replace them with MSD injectors the ticking sound was gone.

GOOD LUCK!!
Old 10-01-2007, 08:49 PM
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Sam Lam
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Chip: One of the best tools to have in your tool box is not expensive and it is called a mechanics stethoscopy. You can get this from Sears for about $20. This little marvel will help you find all kinds of problems with your car.

My son recently had a wheel bearing noise in his four wheel drive A4 Audi. He was damn sure it in the front wheel and had already ordered the bearing (about $200 for this puppy). We put the car on the lift and placed the stedhoscope on each bearing while hand rotating each wheel. We quickly found the bad bearing was the left rear bearing. Piece of cake!

This tool will help you locate the source of the noise in your engine. After you know the source, we can help you solve it. I still believe you have a worn lifter which is out of adjustment
Old 10-01-2007, 09:05 PM
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FF1wms
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Originally Posted by Sam Lam
Chip: One of the best tools to have in your tool box is not expensive and it is called a mechanics stethoscopy. You can get this from Sears for about $20. This little marvel will help you find all kinds of problems with your car.

My son recently had a wheel bearing noise in his four wheel drive A4 Audi. He was damn sure it in the front wheel and had already ordered the bearing (about $200 for this puppy). We put the car on the lift and placed the stedhoscope on each bearing while hand rotating each wheel. We quickly found the bad bearing was the left rear bearing. Piece of cake!

This tool will help you locate the source of the noise in your engine. After you know the source, we can help you solve it. I still believe you have a worn lifter which is out of adjustment
with Bob. I have an 89 and had the same noise. I suspected one of my rockers out of adjustment, and the stethoscope proved me right. It could have save me alot of time screwing around, second guessing, taking apart things that didn't need to be touched.

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