grinding sound then ABS light

I attempted to post this the other day, but the post is old hat now and we have new information. Here goes:
'98 Windstar -- we start the car, everything's fine. Put it in drive, everything's fine, press on accelerator, then a loud grinding sound that lasts about a second coming from the bottom front-left of the car (maybe next to the tire), then the ABS light immediately comes on. The ABS light is not on when starting the engine. What's going on? We thought brake pads, but the grinding sound is not occurring when braking. It is occurring upon the first acceleration after starting engine. The ABS light stays on until we turn the engine off. HELP!!!!!

Hello

I would look for metal shavings/a shinny spot. Pull the wheel off and check it out. When you pull the wheel off you might find the reason for the ABS problem too.

Regards

Dan

Hi.
I had a similar problem on my Windstar. Rust had formed between the ABS sensor and it's mounting pad, which pushed it into the rotating magnets causing a clicking sound, and caused the ABS light to come on.
I removed the sensor, cleaned the rust and remounted it, problem solved.

Hope this helps.
J

Thanks to both of you for the ideas. We are about to do what both of you recommended. A quick question regarding the ABS sensor: what does it look like and where is it found? We've never worked on it before.

Hi.
You can't miss it. You will something that looks like a gear that rotates when you turn the rotor or rear hub. There is a little square piece of steel very close to the gear with a wire leading to it, follow the wire and you will see how it mounts.

J

Another thing to check is that metal shield that covers the inside, bottom, surface of the rotor. I bumped mine while doing my front brakes, and it made a nasty sound once in a while as it touched the rotor surface.

I would do as advised, use a lot of brake cleaner to clean the big gear and magnetic pickup that are the "wheel sensor". They collect a LOT of brake pad dust.
Do NOT use any other type of cleaner than the brake cleaner, as you do not want to get any residue onto the braking surfaces.

Thanks for all of the ideas!! Here's what we've tried: we looked for metal shavings and rust, etc. on the ABS sensor and found nothing unusual. We did, however, find the same metal plate (that Wiswind mentioned in his email) bent out of shape but we took that piece out and hammered it back into its proper shape (as the one on the other side of the van looked) and put it back (Note: All this has taken place only on the left front wheel where it seems the initial sound is coming from - it is hard though to pinpoint the sound). We went out for a test-drive and there was still the same sound followed immediately by the ABS light coming on -- right after acceleration.

We checked the manual regarding the ABS system, and it says the ABS system does a self-check at 4 mph. It also said that a mechanical sound will be heard when the system does this self-check. If the self-check detects any problems with the ABS system, the ABS light will come on. However, the sound we are hearing is a new unusual sound that has developed but it occurs at the same time that the "normal" mechanical sound is supposed to occur at the self-check.

We jacked up the front of the van and accelerated beyond 4 mph in an attempt to more accurately locate the sound. Interestingly, the van did not make the sound while up on the jack. Why would that be?

In the mean time I probablly need to check the sensor on the right front wheel as well and possibly the back wheels too. Could it be that a sensor just needs to be replaced? I just do not know why this would make any unusual sounds upon initial acceleration prior to the ABS light coming on. Can any of you think of anything else?

Another though, may be that your front left wheel bearings have gone bad. This would explain the noise and ABS