About a month ago, i started having this problem where when my car was cold, and i put it in reverse, i would get a big "THUMP" as if i had a bad mount. If i was to let the car warm up, it would be fine. It only happens when the car is cold and the rpm's are still revving high. I took it to my mechanic, and he discovered 3 bad mounts. I changed the front engine mount, the passenger side engine mount, and the bottom rear tranny mount. All this, and im still having the same problem. Could there be another mount that would cause this happen. I know theres a rear engine mount, but i could not see it. Thanks in advance!

 

i have the same problem but mine only thumps when its warm. i know that i have bad motor mounts but then it thump it hits really hard. the back mount is in the back of the engine directly in the middle.

 

The mounts are probably bad. But I also had that same "thump" when my tranny was about to go and was slipping. When you first started the car when it was cold, it gave that "thump" and slightly rock the car. Have you got your tranny replaced yet? Maybe its time to take it into the dealer and check it out.

 

Its only happening in reverse though. I would think that if the tranny was going bad, it would make that thump whether the car was cold or not. Just for the record, i have a 99TL with the 4-speed.

 

there is a Rear engine mount

 

when looking at the heads on the engine, should the back sit lower than the front? I changed my front mount 6 months ago. and my side also but now that I am doing the 7 year or 100k service (at 8 years and 90k) I noticed the back is lower with the side mount off. Should I change the rear?

 

The thump doesnt necessarily mean a bad mount, it could just be a tranny issue. I have all new mounts and mine still thump, but it does almost all the time, id say get it checked out by Acura or wait till it gets worse and then have them check it. Are you still covered by the trans warranty?

 

My question is: If it was an actual tranny issue, wouldnt it make that thump all the time? mine just happens when the car is cold and revving above 1k rpms. Once it warms up, and the rpms drop, i can put it in reverse and it is fine. u still feel a slight shift, but nothing compared to the thump it makes when the car is cold.

 

Did you ever figure it out? I am having the same issue after replacing the front and rear mounts.

 

I only have this issue if I Reverse then quickly engage D5 While Stone Cold, No Idling in the Morning.

Solution?:
JUST Let the Damn Thing Idle for 1-2 Minutes in the Morning PROBLEM SOLVED!

 

The TL trans seem to drop hard into reverse when cold. Hardly ever when warm. Bad mounts make it feel a lot worse.
And yes, when viewed from the side the engine does appear to be leaning toward the back.