Is this normal? Hear for yourself!
http://www.youtube.com/watch?v=PEnvt...e_gdata_player

 

do you have an AEM CAI ?

That sounded to me like the sound of the AEM filter, it makes the same sound when I turn my car off

 

Nope, my engine is all stock.

 

How many miles are on the car?

I have been recently shopping around with dealers close to my area to get my 105K maintenance done. One of the dealers asked me if I had a knocking noise when starting the car and turning it off. He mentioned that sometimes the motor mounts have to be replaced around this time too. May very well be what your hearing?

 

There are 49k miles on the car, I'm taking the car into Acura on Monday before my warranty expires.

 

WOW....

yes i would take it to the dealer and see what they say....since you are under warranty it should be covered....

 

It could possibly be mounts.

You can try going from drive to reverse fairly quickly and see if you can recreate the sound.

While driving, stick it first gear, get the rpms to 3-4,000 and floor it and let off abruptly and see if it makes the sound. If it's the mounts, you should be able to recreate it but it probably won't be as bad as in the garage.

Another test, rev it to 2,000rpm and shut the ignition off. See if it only makes the noise right before the engine completely stops or if it does it right when you turn the key off.

The other thing, it almost sounds like the throttle body is slamming shut. Probably not but it's hard to tell by the video. I normally would not recommend this but when starting, hold the gas pedal at about 1/4 throttle and note any changes. If you hold it too close to full throttle it will shut the injectors off and not start.

 

Thanks I hate cars, I'll those things a try!

 

Did you ever resolve this issue? I have the exact same problem.

 

possibly motor mounts.

 

Stupid question but you do use premium fuel right?

 

I took it to the dealership and they said all the noises are normal.

I only use Chervron 91 gas.

 

It's not normal. The sounds themselves sound normal but much louder. Have you ever checked the stock intake system to make sure everything is connected securely? Starting from the throttlebody and working your way past the filter.

The startup sounds like when the timing switches over from crank to run. The turn off noise sounds like the normal noise it makes but amplified.