I tried to read thru other threads but none of them seems to be my situation.

I cold start my car and then I put my 5AT into "Reverse" and pull out of garage. Then I put into "D" and start driving for about 5 to 10 seconds slowly.

There is a single "Chunk" or "Bam" kind of sound I can hear&feel coming from lower middle engine compartment. It did it from day one I got the car. Is this something not normal?

It doesn't happen from warm start. It takes few seconds after all the instrument light checks are done.

 

Pay attention to the A/C. Sometimes when the clutch first engages it will make a loud clunk sound. This is very normall. Now this only on the first time it engages, like in the morning. I have seen many like this.

 

Sounds like the ABS self check

 

Thanks for the reply.

It is very similar to A/C engaging sound but about 3 times louder and happens ten to twenty seconds after when I start driving forward.

A/C engages right after car starts usually even before I put my gear into reverse.

My last car with ABS didn't have such sound. I can feel this "Clunk on my acceleration pedal as I slowly move forward"


I found following on Acura Ownerlink but doesn't seem to be my issue (dealer would of checked my tranny fluid level at A1 service, wouldn't they?)

"Clunk (a dull banging or thump, as if something were being dropped)
Loose or worn universal joint or rear differential; low transmission fluid."

 

My wife drives a Camry SE and has the same issue. Turns out it's her ABS check and it's normal (on her car at least)

Gotta agree with nfnsquared on this one with my limited knowledge.

BTW - Our third car also has abs with no clunk

 

So your car does this "clunk" too about 10 to 15 seconds after startup?

 

It'll thump at colder starts at approximately 10mph...

 

It is definitely ABS self test. I don't even notice it anymore at 11k+ miles. I don't hear it or feel it anymore at all, but I know it still does it's job because sometimes when exiting the drive way I hit the brakes at the same time as the ABS is doing it's test.

 

I thought I'd chime in. My 99 Honda Accord did that, almost from the first day I bought it with 7 miles on it. I'd start, reverse, then put it in forward and it would 'clunk' after about twenty feet (if that). It was weird, not terribly concerning, but definitely out of the ordinary. I took it in to the Honda dealer. I tried for several minutes to get it to happen at the dealership, with the service manager in the car, and I couldn't. Then , as I was getting out of somebody's way (reverse, then pull forward quickly), it bumped. He said, "yep, that's your torque converter!" and I said, "oh?"

and he said, we'll order a new transimission right away. No problems from the new tranny.

 

My TL clunks after I drive it about 10 or 20 feet too, when i drive it for the first time that day. Totally normal.

 

The "Bam" or the "clunk" you are experiencing during the first cycle of driving is the ABS pump pressurizing the ABS brake lines. This is perfectly normal and is unclear why Acura did not attempt to isolate the ABS pump. This is also common with the TSX.

 

I have a 2004 and started posting this very question when mine was new. My "clunk" was the ABS resetting at 8 MPH. I now have 9,800 mile and the clunk is gone. I did take mine in when new and the dealer told me ABS resetting, totally normal.