Thread: Knocking Issue

Just picked up a 97 GTP w 200k for fairly cheap to swap in my 98 GTP dirt track race car. I noticed it had a knocking sound coming from the passenger side pulley areas and would go away when you revved it up. I assumed it was the sc coupler going bad which i was going to swap sc anyway since mine already has the 3.4 pulley on it. Well i started to diagnose the problem by taking off the sc belt to see if the sound would go away but it didnt. I did notice that the sc pulley does have back and fourth play tho. So i then took off the drive belt to see if it could be any of the pulleys, pumps or ac, the knocking doesnt seem to real appear unil after i let off the throttle. Could this be a sign of KR? Im not sure what octane the previous owner ran but i know the air filter and tube was totally clogged which i already took off. I dont think its a rod bc the thing idles nice, just doesnt have any power when you take it down the street, but it does have full boost. Any suggestions or ideas would be welcome. Thanks

Forgot to mention that there are no CEL codes

Originally Posted by Explicit_Spade

You shouldn't be able to hear kr. You probably have a bent rod or something of that nature.

i hope its nothing with the engine, glad i only paid $350 for the car incase it is. Car is completly stock, younger kid owned it and was about to drive it across country before his buddy wrecked it. Could the pcm be holding it back somehow?

So I've got both belts off and it idles fine and quiet, when I rev it up it has a quick clicking noise but goes away, could anything in the supercharger cause that?

took the passenger tire off and it sounds like its coming from crank pulley area, put the belts back on and it just rattles at idle and goes away if you gently push the throttle. Took it down the road and it barely has any power when you give it full throttle, pops and pings as well. Wanna try to figure if the motors still good or not before i pull it, if not ill just scrap the whole car and get my money back.

I know there arent any CEL's, but could that be bc the battery is shot and doesnt hold a charge? could the knock cause the knock sensor to go off and put the car in like limp mode? Would really like to figure this out so i can decide weather the motor is good or not. Any help is appreciated. Thanks

guess everyones away for the holiday weekend. LOL

Originally Posted by RickyRacer21

I know there arent any CEL's, but could that be bc the battery is shot and doesnt hold a charge? could the knock cause the knock sensor to go off and put the car in like limp mode? Would really like to figure this out so i can decide weather the motor is good or not. Any help is appreciated. Thanks

Post a video clip of the engine running.

Just noticed that the whole harmonic balancer pulley spins around with both belts on while the car is off bc rubber is no longer attatched in the center. Could this cause the knock and/or loss of power? Luckily the pulley on my other motor is in mint condition.

So its possible it could be kr if it has low octane gas, clogged cat or crappy plugs? Could anything w the harmonic balancer cause the knocking and loss of power? Waiting for vid to upload

cant get a vid to upload from my phone, doesnt seem like anyone has much input so ill just have to diagnosis it myself and hope for the best

thats what im gonna do next, swap in my 104's out of my other engine and disconnect the downpipe, after i swap the harmonic balancers which ive got both bolts off, just need to get a puller. Hoping thats the cause of the knock

swapped out the plugs (ngk iridiums) for my 104s, didnt seem to make any difference. Also swapped out all the coils, didnt see no change. I did get the harmonic balancer swapped out and that took care of the knocking and keeping the battery charged. Also got the whole exhaust cut off at the downpipe. Car seems to start up and idle fine, revs up fine too but you can hear some hesitation when you do. Took the car up the street and shifts and drives fine under normal acceleration, but as soon as you punch the gas it pops and sputters and doesnt take off at all.