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clunk going into reverse????

V

vader99

New member
On every cold start after I try to let the car warm up a bit there is a definite clunk in the front end when I put the car in reverse from park.

It doesn't do it hardly at all if I go from park to drive.

When the car is fully warmed up and the engine has reached its normal idle rpm the car shifts into reverse with hardly any clunk at all. Now, is this just due to the higher idle rpm's from the cold starts?

Would this be a transmission or engine mount problem?

thanks...
 


is the motor visually moving a lot when you shift? if so your motor mount is probably shot. the tranny mount isnt as pronounced, but they are easy to replace when youre under the car.

have you recently put on headers? could be the downpipe hitting the sway bar.
 
No, the car is a bone stock 99 gtp sedan. Motor does seem to move (or movement is felt from inside the car) when the clunking occurs.

So, it sounds like motor mounts then???:th_scratchhead:
 
pop hood, start the car, (if your e-brake works) set the e-brake, put car in Drive, make sure your car isn't moving!, stand to the side of it and manually give it throttle (using the throttle cable) and see how much your motor moves. If it moves way to much and makes a Bang! the motor/trans mounts are shot.
 
Open the hood and have someone rev the engine in PARK, watch the engine.
You can also stand NEXT to the car, have somone put it in PARK, have that person also hold down the brake, and then give the car gas, watch the engine.

If it rocks excessively, or jumps, you got engine mount issues.
 


Okay guys....I popped the hood and got in the car and started it up and then watched through the windshield as the engine jumped as I put the car in reverse. It definitely jumped and made the clunking noise while doing it. So, this means some mounts are bad, correct?

Now, are worn dog bone mounts capable of allowing the engine to jump that much or would the lower mounts more than likely be the culprit(s)?

I went to the local GM dealer up here in Canada and they wanted approx. $800.00 for all four mounts. I definitely don't want to spend that much if I don't have to so I would like to try to eliminate some from the situation if I can.

thanks...
 
vader99 said:
Okay guys....I popped the hood and got in the car and started it up and then watched through the windshield as the engine jumped as I put the car in reverse. It definitely jumped and made the clunking noise while doing it. So, this means some mounts are bad, correct?

Now, are worn dog bone mounts capable of allowing the engine to jump that much or would the lower mounts more than likely be the culprit(s)?

I went to the local GM dealer up here in Canada and they wanted approx. $800.00 for all four mounts. I definitely don't want to spend that much if I don't have to so I would like to try to eliminate some from the situation if I can.

thanks...
Click to expand...
You can get normal upper mounts for like 30 bucks, or ZZPs polyurathane mounts are only 60. Lower mounts are even cheaper. Dealerships are ****ing retarded.
 
BwolfGT said:
You can get normal upper mounts for like 30 bucks, or ZZPs polyurathane mounts are only 60. Lower mounts are even cheaper. Dealerships are ****ing retarded.
Click to expand...

Okay, great. Now exactly where can I get these cheaper factory mounts from for the top and bottom that you speak of? Those prices are more in line with what I thought they should be. Sorry for the questions but I am new to the grand prix scene. :th_scratchhead:
 
vader99 said:
Okay, great. Now exactly where can I get these cheaper factory mounts from for the top and bottom that you speak of? Those prices are more in line with what I thought they should be. Sorry for the questions but I am new to the grand prix scene. :th_scratchhead:
Click to expand...

Auto Parts Fast at RockAuto

They're I think $28.99 or something like that from there for stock replacements.

Or if you're into modding you can get these ones from ZZP for $59.99

ZZ Performance
 


If it was bad mounts wouldnt it do it all the time? not just when its cold? On cold starts trans fluid is much thicker allowing for more pressure to build behind the reverse servo making it go into reverse harder then normal. Anyways there is a lot of movement of the mounts with a stock car and i doubt it is the mounts causing the clunk because the mounts are made to absorb the shock of the motor/tranny/roadnoise. Mine hits reverse hard also and i have poly mounts and it goes away when it warms up.


Also Transgo makes a shift kit which includes a new reverse servo seal that corrects the promblem of no reverse or slips into reverse. I dont think this is the promblem though just thought i throw it out there.
 
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Actually, after paying more attention to the clunking, etc., the engine does move alot even after warm when shifting to reverse. Going into drive the engine doesn't move as much but it does move. Reverse seems to move more in all situations.
 
so are you thinking its the mounts still then?

let us know if anything you do that fixes the promblem
 
well since the original poster has not listed if he ever solved the problem I figured I would. I was having the same problem and replaced the motor mount (lower) and zzp polys up top... problem is still there only when the car is cold. I did not change my trans mount because it looked in decent shape compared to my motor mount. If anyone can figure out why it does this I would really appreciate. I always reverse into spots if im going to be parked a while because I HATE hearing that noise.... its painful :mad:
 


I just replaced all the mounts, upper, lower, and trans, and it fixed it. Trans mount didn't look bad compared to the motor mount either but it was still worn so I replaced it.
 
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