Tapping/ knocking in nuetral when snapping throttle

[turbosam6]

Last night I had the car out, and noticed when I parked it, I heard a knocking noise from down low. If you rev it in park or nuetral, it taps or knocks a little. Doesn't seem to do it in gear. Its not very loud. It almost sounds like the convertor is rattling. Its a 3200 Vigilante l/u. I did check the convertor bolts, they are tight. The oil psi is good too. Any ideas? Car still seems to run fine.

 

[Paul Clark]

Do you have the correct belt?
The Gates replacement I got was incorrect and caused the tensioner to make noise.
Correct length is 63 1/2"

 

[BobbyBuick]

tensioner or belt.
check IC bracket bolts cam sensor makes a clicking sound sometimes .if if happens on the rev up probably IC brackets loose at motor

 

[turbosam6]

I forgot to mention that if you pop the hood and do it you can't hear it at the motor. Like its coming from under the car. I have a PTE FM, no ic brackets. Belt is fine, tensioner is new. Doesn't matter, since you can't hear it when you stand over the motor and move the throttle by hand at the TB. Maybe an exhaust leak?

 

[trbojo]

i had a similiar situation. i have a pat's 10" l/u convertor. if you had the car on a lift, you could hear the noise coming directly from the convertor. i also had a shudder problem when cruising. they sent me another one-problems gone. they still haven't got back to me yet to let me know what they found.

 

[Paul Clark]

Check the convertor bolts. Bet a couple are loose.

 

[Fuelie600]

If it's a Vigiante multi-disc, they do rattle when in park or neutral. When in gear, they are quiet.

 

[onebadv6]

check the crank shaft sensor may need slight adj. could be rubbing pully
sounds like a rod bearing when its rubbing or exhaust leek

 

[DonnieShort]

Originally posted by onebadv6
check the crank shaft sensor may need slight adj. could be rubbing pully
sounds like a rod bearing when its rubbing or exhaust leek

I agree, crank sensor sounds pretty rough if it gets out of adjustment. Also, check the a/c nut that's just to the right of the tensioner mine has come lose before and sounds like a rod knocking. The nut actually hits the tensioner pulley. Good luck!

 

[Haynesie]

try checking the fan near the intercooler if you have stock location one...i have seen the bolts come loose before, but if it goes away after in gear maybe not, but check anyway since its an easy fix to tighten the bolts, or replace them if they are broken...its in that general area anyway

 

[turbosam6]

As mentioned previously, I checked the convertor bolts, and I have a PTE FM. Took it out last night, it will only do it when the car is warm. I don't hear it at all in gear, but in neutral I can hear it. If you bring up the revs slowly it won't do it, just when you give it a sharp rap of the throttle. Also, as I said before, you can't hear it when you stand over the motor with the hood open and rap the throttle, its not the accessories or sensors.

My convertor is a single disk lockup, not a multi disk. Its funny you mentioned that, because I noticed kind of a strange vibration driving at higher speeds the other day but thought it was because I had the dump open. Wonder if this convertor is messing up?

 

[onebadv6]

you say as soon as you tap the gas the tick gets louder but instantly gose away my car does that I was told by a trans builder it was a valve in the tranny not to worry And I said I hope your are right
it has done this form day one

 

[matt87]

try driving slowly by some parked cars or buildings and see if you hear it. i had a similiar noise awhile ago. turned out the bottom end was going south. couldnt hear it from up top at all. hope yours is ok.

 

[BobbyBuick]

a BAD THRUST WILL MAKE A KNOCKING NOISE.CHECK IT BY REMOVING THE BELT AND PUSH PULL ON THE BALANCER

 

[Chuck Leeper]

?????

Ya, what Bobby said... Thrust brg going south.

I told you, you should buy my car!!

 

[Luz2av6]

If it is a vigilante multi-disc converter than it is the clutches in the converter making the noise. when you put it in gear it goes away. I know three people who have a vigilante converter and they all do it including mine.

 

[turbosam6]

SINGLE DISK CONVERTOR. F' it, thrust goes, it goes. That will be the final straw and this car will be gone, it will be time to buy an LS1 or 03 Cobra. I'm thinking exhaust leak, but since my hand is messed up, I can't work on it.

 

[AirBuick]

Was this situation ever resolved?