Grinding Noise On First Accelerate at 2-3K RPMS

Post by **velorider** » 28 Mar 2009, 23:11

I need some advice about a grinding noise when first accelerating. If the car has sat for 15 or more minutes, when I first accelerate there is a quick grinding/thunk noise. Happens only once and drives fine there afterward. The noise sounds like something releasing, like something is stuck. The noise seems to come from the front-end, at or around 2-3K rpms. I recently replaced the TCV, with ipdusa version. The noise seems to have started around the same time. The old one was bad, preventing the turbo from kicking in. Maybe something in the turbo is stuck and releasing...

I'm wondering if anyone has experienced similar noise and what was the cause or advice as to what to look at to identify the cause. I've jacked up the car in neutral and spun the tires. Nothing seems to grind or induce resistant.

I'm at a loss. I'm hoping I could get some advice to help pin point the problem. I'm hoping the answer doesn't start with "trans".

2002 S60 Volvo 2.4T, 86K miles.

Thanks
John

billr99 · Post by **billr99** » 30 Mar 2009, 05:05

Note the speed when it occurs. Could be your ABS going thru its "boot test" which occurs at 25 mph (if I recall correctly) and only does it once in a driving cycle. On mine, it always seems to come from somewhere underneath but central to the car.

Cheers,

Bill

Post by **velorider** » 30 Mar 2009, 20:22

Thanks for the reply. The noise does occur around that speed. Maybe a few mph slower. The faster the acceleration the loader the noise. Sounds very much like the cause of the noise.

Update:

With the additional information about the abs "self test" I found a another post:

http://www.volvoforums.org.uk/showthread.php?p=196756

Sounds like the sound is normal and nothing to worry about but I never noticed the noise previously, would this be an indication that of something wearing out?

Thanks
John

billr99 · Post by **billr99** » 31 Mar 2009, 05:44

For me, the sound kind of comes and goes. I'm sure it is there all the time, I am just either more or less aware. Ambient noise probably plays a factor as well. In any case, I wouldn't worry about it if all other aspects of the braking system are up to snuff.

Cheers,

Bill