Does something "engage" after taking off and getting up to 5-10 mph or so?

[rawbutt]

I've got a 1992 Deville with 74K. Just trying to diagnose something that very well may be normal....it's been doing for as long as I can remember. I get in the car, start it, and take off normally and within a few seconds, it sounds like something "engages"...almost like something that turns with the engine "kicks in". I'm having difficulty finding words to describe it, but being an anal kind of guy...I've always been curious about what it was and if it was normal. It's not horribly loud or anything and someone riding in the car with me may not even notice it, but now that I know it does it every time, I hear it every time.

Thanks in advance!

[2000snowflakedeville]

what your describing might be traction control or it simply shifting gears. also might be a bad motor mount.

[revdowrong]

It might be the air pump coming on for the rear air struts.

[2000snowflakedeville]

thats true my 90 deville usally raised back up about 30 after i got in the car. but you could hear the suspension rise.

[submariner409]

Start the car, after an overnight period, and just sit. After 6 seconds does something behind your right ear go "Hmmmmmmm" for 3 seconds and quit ?

It's the rear level control compressor proving out.

Open the trunk, start the car. You and a friend sit on the trunk lip. Does the compressor start and level the car ? OK, now y'all hop off and quickly listen under the right rear fenderwell. Air bleeding down ? Good to go.

[David Jenison]

Does the noise continue until you turn the motor off?



DAVE
'97 Concours

[rawbutt]

Thanks for the prompt replies guys...

My noise only lasts for about 1 second...always exactly the same sound and same duration. Sounds to me like it's coming from somewhere up front but not sure. I haven't really tried narrowing it down and troubleshooting exactly when it happens, such as whether it's only after taking off from a cold start vs. every time i take off, even when it's warm, etc.

I don't believe it's the sound of shifting gears, but guess traction control could be a possibility. I wasn't aware of the 1992 Deville having traction control?

[JK2402]

Its the ABS pump doing its self check. Happens every time you start the car around 5-10 mph. That just lets you know its working!

[submariner409]

I'll buy that, now that we know what end of the car the noise is coming from.

[rawbutt]

What a relief !! It's a relief knowing that the sound is normal

Thanks again for all the helpful input.

Robert