Odd Noise

**tdaye** · 06-16-2009

Hi Guys. i have a 2002 GTP. The problem I have is an odd one. I start my car and put it into ANY gear, once I hit 5kph I feel/hear a grunt sound. It's only for a second and it's only after starting the car and putting it in gear the first time. I feel it on my feet. I never hear or feel it at any other time. It makes no difference if my TCS is on or off, it also makes no difference which gear I am in. I have had it to a transmission place and they don't think it has anything to do with the transmission.

Start my car, put it in any gear, drive 5+kph, grunt sound, very quick vibration on floor. never hear it again untill I restart the car.
It sounds like something is engaging ?

**BIGTMANE** · 06-16-2009

I have an 04 same exact problem. I hope someone replies to this

**CTKGP09** · 06-16-2009

does the car jerk? or do u just feel the vibration? and can u hear it really well or if u r listening for it?

**tdaye** · 06-16-2009

There is no jirking or slipping. You can feel it and hear it, it's loud enough to make you think something is wrong. You don't have to listen for it to hear it.

**CTKGP09** · 06-16-2009

ok i know wut u are talkin about then mine does that too but its quiet and i really cant feel it in the pedals...i can hear it tho...my aunts 2002 aurora does the same thing when the cars on but not in gear and its pretty loud and i was told that that sound is the loadleveler...like the cars computer automattically ajusting the ride hight...but idk if GPs have that?

**tdaye** · 06-16-2009

It does the same sound and it feels the same every time. It's for a split second when the speedo hits 5kph for the first time after starting up. It will never do it under any other condition.

**J GTP** · 06-16-2009

Same here. Kinda wierd, I was just wondering about it this morning when I went to work.

I remember my mothers Buick Century did it for a while too.

**tdaye** · 06-16-2009

It's like something is engaging right ?

**GMPUNK** · 06-16-2009

Mine does the same thing, awalys wondered what is was, but I guess everyone does it. It sounds like something rubs for a split second when you first take off after starting the car, and won't do it again until the car is shut off and started again.

**tdaye** · 06-16-2009

Exactly! You can start and stop the car over and over and it will do the same thing each time. I guess if many of them do it, it's not a big deal.

**CTKGP09** · 06-16-2009

must b a thing of our cars?!?

**BIGTMANE** · 06-16-2009

I guess it must be. Mine does it all the time and I'm like what gives. Doesn't seem to be hurting anything tho

**blueguy** · 06-17-2009

Don't worry about it until it breaks something. I have no idea what you guys are talking about...sounded like a mount issue until you said it doesn't do it all the time.

**CompCam21** · 06-17-2009

i could be way wrong but it could be the torque converter locking or unlocking...my buddy has a diesel truck that he can manually lock/unlock the torque converter and it makes a sound and shake like that...but idk i have never noticed it in my car but now i will pay attention

**tdaye** · 06-17-2009

I'm told by someone on a different site : The abs system does a check i believe at around 4mph only the first time you start the car. It sounds like that is what you guys are describing because i wondered the same thing when i first bought the GP. If it only does it once and is when you hit around 4mph right after turning the car on its probably that.

Is there a fuse or a way to disable the ABS ? It would be cool to know one way or the other if it is the ABS doing a check.

**tdaye** · 06-17-2009

I've also found this :
The EBCM performs the ABS initialization test once each ignition cycle when the vehicle speed reaches 4 mph and the EBTCM does not see a brake switch input. If the EBTCM sees a brake switch input, the initialization test runs when the vehicle speed reaches 9 mph. The initialization sequence cycles each valve solenoid and the pump motor, as well as the needed relays, to check component operation. If any error is detected, the EBCM will set a DTC. The initialization sequence may be heard and felt while it is taking place, and is considered part of normal operation.

Your brake system is acting normal.

**BIGTMANE** · 06-17-2009

Yea, at a slow crawl it does it. And for me it only does this once the car has been cut off for at least 2-3 hours. So maybe thats what it is.

**QUICKSILVER462** · 06-17-2009

My 2000 Blazer, and my 2000 GTP do the exact same thing, that is described above. When I park the one I am driving in the driveway and drive it for the first time of the day, they both make the same noise at near the same spot and speed in the driveway, it's gotta be the ABS system check.

Dean