theoldsouthern

This is my first post to the forum and I have spent some considerable time searching through past posts to find an answer to this problem so I apologize if it has been covered.

I have a '98 4Runner Limited 4x4 Auto with the 3.4 and close to 150k miles. On a cold start or after the truck has been sitting for a while, there is a grinding noise that seems to be coming from the front left. It only happens when I pull forward (out of a parking spot). I cannot seem to replicate it when it is in park. I have tried turning the wheel back and forth. Also, if I put the truck in D and inch forward it does not happen. It only occurs when I go ahead and pull out.

Now the sound:

It only lasts about 1 second and it almost sounds like a ratchet tightening up. It is definitely in the front of the truck and possibly higher up in the engine bay.

My first thought was power steering and when I checked the fluid it was a little low. I topped it off but the sound still happens. The odd thing is that it only happens when you are in D AND pulling forward. You can be in P or in D and sitting still and it will not happen.

Any thoughts?

Thanks for the help.

UKrunner

CV joint?
Diff low on oil?
Exhaust manifold expanding?
Engine mount creaking under torsion?
Trans fluid low?
Brakes binding?
Top hat on shock worn?
ABS pump?

theoldsouthern

It is definitely not a creaking noise. Tranny fluid is fine. Could be differential or ABS pump.

The sound is mechanical like a pump or gears.

theoldsouthern

It appears that is was the ABS Pump. I pulled the fuse and the noise has stopped.

j2the-e

No ABS lights? This is probably normal. The pump is pressurizing the accumulator

theoldsouthern

ABS light is on, but that was expected. The ABS actually kicked in when I was going over a patch of small, rapid bumps. I could really hear the pump and it did not sound normal. It spooked me enough that I think I will leave it disabled until I can have the pump checked out.