Thread: "Clunk" on initial rolloff

My 97 GTP has been making a single clunk sound each time I start rolling after starting the engine. It's been doing it for years, but it used to only do it the first startup each day. Now it does it if I park the car any longer than 10 minutes. If I "park" it and leave it running, nothing happens. Also, when it makes the noise the headlights and dash lights (if they're on) dim for that split second. If I happen to have my foot on the brake, it softens up and the brakes cease to function for that split second (kind of scary when backing down a steep driveway!).

on my car, the ABS tests itself, and almost sounds like a grinding noise, If you gently rest your foot on the pedal it will feel like a slight vibration, could this be what your experiencing?

Pull the abs fuse and see if it still does it?

Check your cradle bolts.

Originally Posted by 02BlueGT

on my car, the ABS tests itself, and almost sounds like a grinding noise, If you gently rest your foot on the pedal it will feel like a slight vibration, could this be what your experiencing?

Pull the abs fuse and see if it still does it?

Sounds like this is the problem. Mine does the same thing. Lights dim a bit. Makes a grinding like sound. Everything is normal.

I'll try the ABS fuse and see what I get from that tomorrow.

Also, it used to turn on the ABS and Parking Brake lights sometimes when it did it. That has since ceased with the replacement of both front wheel hubs. Should I check out the rear ABS sensors?

^^^ that makes sense, it was finding the errors in the hubs and setting off the system...... Tell us what happens when you pull the fuse, the abs light should be on(otherwise you pulled the wrong fuse :P )

^^^ did you go GM or cheap, I've heard of the cheap ones going out after a few days....

I pulled the ABS fuse this morning, and have been driving it around all day like that. No noise now. The whining from (I'm assuming) the power steering pump also seems a bit quieter, but that may just be my imagination. So, what do I do now? Drive around without ABS, or is there something more specific I can tinker with?

That means that you are hearing the normal ABS self-test, It is just something we all live with, I would suggest putting the fuse back in now that you know what the noise is

Originally Posted by ranman

I had a "clunk" as well so I replaced the front DS wheel hub assy about 3 months ago and am now starting to run into the same problem. There's more symptoms. Car pulls a little to the left, theres a metal scraping sound (kinda like the break pads are worn, but they're not) when turning left, and occasionally when breaking I feel/hear a metalic grinding sound. I hate to think the wheel hub is bad again, but I heard that it is not uncommon to get a bad one.

Does anyone know if there is something I'm missing? Could there be something else causing the wheel bearing to go bad?

Sounds like a bad wheel bearing to me. But then again, its hard for me to tell sitting here in my chair at work.

That means that you are hearing the normal ABS self-test, It is just something we all live with, I would suggest putting the fuse back in now that you know what the noise is

I agree. The noise is normal ABS operation. Just a self test to make sure everything is working ok. No need to disable your ABS because of this normal sound. I would suggest putting the fuse back in and be assured that everything is normal.

Originally Posted by Tengis

Check your cradle bolts.

After I installed my front sway bar, my car does the similar grind/clunk/rubbing noise on any takeoff. It almost feels like something is rubbing when I quickly accelerate from a stop.

Where would the rubbing come from on the cradle bolts? I suppose I can check the bolts this weekend, but I'd rather get a heads up before hand.

Thanks

If the bolts are loose, the whole cradle could be moving a little, and anything attached to it (control arms, steering, sway, engine, tranny, etc).

Shiza - I'll have to check it out this weekend when Jacob (URLosn) shows me how to do the LIM gasket...

I'll go easy on 'er until then.