Hi,

I have a 2003 Acura TL-TypeS. I brought it to the service center yesterday because there is a low thumping noise (sounds exactly like the bass on a stereo cranked up). While it's "thumping", the idle goes down to the point where the car nearly stalls, and at the last moment, the idle goes up above 1000rpm and back down, then the cyle starts over. It doesn't happen all the time, but it does happen more often then not. I was able to show it to the service guy. At first he thought my stereo was on and I had the bass pumped up (which is exactly what it sounds like). Both he and the tech he brought out promptly noted that they've "never seen this before".

Here are the facts:

1) I had the transmission replace a few months ago due to hard-shifting

2) I had the timing belt tensioner recall done shortly after

3) After the transmission was replace, the car's fan would go on everytime I would turn off the engine. A couple of weeks after, the car would overheat. I brought it to the dealer and they blamed the problem on an air pocket in the radiator.

4) Also shortly after the transmission was replaced, this thumping/idle problem is happening.

I called the service center last night to see what's going on and they told me that they called the corporate tech guys and they've never heard of this problem. They also check the "technet" or something like that, and no one has reported this problem. They're having their lead/foreman tech take a look at the car today.

Also some more facts:

1) After the transmission was replaced, I swear I feel a loss of power, it also seems like the gear ratio has changed.

2) After the transmission was replaced, there is a hissing noise when I accelerate the car (under heavy acceleration)

3) the thumping/idle problem does NOT occur when the engine is cold.. only after it's warmed up does it happen.

I'm not really that knowledgeable about engines, but has anyone ever heard of this problem? It seems that it all came about after the transmission was replaced. It scares me to think that no one has a clue on what's going on. It's practically a new car and I'm already having doubts on the reliability on Acura's.

Thanks,
Chris