After my L98 warms up, it has a metal tapping noise and an occasional clunk sound, this couldn't be a spun rod bearing or the rod knocking could it. There is no performance difference between when it is hot or cold. Also, when I rev it up when it is tapping the taps get faster with RPM but when it idles down the taps turn into a few clunks and back to taps. What could this be?

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1989 Formula 350

 

not at first. But real soon afterward. When the bearing spins, it normally stacks on top of the other. This makes the clearance on the otherside pretty bad. That piston will eventually hit the head.

 

could it be bad lifters? hows your oil pressure? just athought if it doesnt do it all the time i dont think its a bearing. but i could be wrong i dont know much about that , just seems to me it would do it all the time from a bearing

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87 z28 bowtie aluminum 420small block dry sump crower lt. wt. knife edged crank oliver lt wt rods brodix track 1's super ram intake slp 1 3/4 headers accel dfi art carr 700 r4 3.42 gears ssm sub frame/ladder bars.....other parts on the way ,soon to be finished!! couple more weeks!!!

http://people.ne.mediaone.net/gdm

 

my 89 Formula had a tapping noise that turned out to be the exhaust manifold gasket. I would open the hood and try and ID the location of the tap to a specific side of the engine and start checking the bolts. Then I would check the rear transmission mount, as that has been the only source of a clunk I have ever had.

Just my $.02



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Chris G
91 TA WS6


See more of her here!
Wise man once say "Red ones go faster!"

 

If the "clunk" takes place when you shift into reverse or when you accelerate real hard it is probably your trans mount. All knocks, pings and ticking require immediate investigation and they can only get worse before they get better.

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86 Camaro Black SS Coupe, T Tops, Flowmaster, Custom Paint, Dunlop Road Kings S/R tires, Wheel Country Directional Chrome Wheels,new charcoal & gray interior including seats and door panels, new carpet and headliner, complete front end suspension rebuild, new Valve seals, and more mods to come
'91 RS 5.0 TBI = Waiting to be modded, but has all of the toys inside.

http://www.angelfire.com/sports/niterider/86camaro.html
Morgan_Andre@hotmail.com

 

My oil pressure is always pretty high. The ticking is the loudest under the car and the clunking sounds like it is coming from the middle of the engine.

 

I spun a bearing once and you definately know it!!
All hell breaks loose when you spin a bearing.
At idle it's not that noticeable and you might hear a squeel at times.
Then when you give it some gas it becomes more and more noticeable.

Hop in the car BAREFOOT.
Start the car and gently press on the gas slowly getting higher and higher in the rpms.
Sometimes you can feel a rod knock through the gas pedal.

A spun bearing and rod knock have more of a clacking sound than a tapping one. If you were running the engine hard you might have spun a bearing.
But the symptoms you describe don't sound like a rod knock to me.

Check you tranny mount and go over the entire engine area from top to bottom.

 

The ticking could be your fuel injectors (very common) or an exhaust leak. The "clunk" sounds like the tranny mount.

Sounds like you have 2 separate issues.

 

Would a loose or broken tranny mount make the clunk sound like it is coming from the engine?

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1989 Formula 350

 

I would think that if it is a spun bearing you would definately know it. That is how i got my Iroc, some kid spun a connecting rod and took his crank out. He couldn't afford to fix it so I bought the car from him.

Anyhow like the others said, don't let knocks and clunks continue, only bad things can happen if you do.

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LB9 305 TPI
Speed Pro forged pistons
Accel HEI Distributer
Cam & Crank from 96 Vette
Dynomax muffler
No cat

 

More like either the center of the car or possibly the rear. When mine went, it came more from the rear of the car. But others have said that it sounded from more like the center of car. Could also be a broken/worn motor mount if it sound like its from under the hood or the engine.

But DO check the tranny mount. Very common problem.

 

I heard my buddie's LT1 TA today and it had the same ticking noise and a broken tranny mount. The clunk from the broken tranny mount came from when the tranny itself hit the bottom of the car when he gave it gas. He doesn't know what the ticking noise is but his hasn't gotten any worse and he has had it for awhile, like mine. His ticking didn't turn into knocking as it idled down though. My mom's baby LT1(4.3L) has an exhaust leak tick so I know what that sounds like. What does inproperly set valve lash sound like?

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1989 Formula 350