hydraulic pump sound when in 2nd gear

[LJRuddy]

Ever since I can remember, I've noticed an odd sound coming from the engine bay when I am accelerating around a turn or when using moderate throttle in 2nd gear below 3500 rpm. The sound is hard to describe but if I had to pick, I'd say its a cross between metal on metal rubbing and a hydraulic pump that is trying to push 10 degree fluid through a hose. The sound is not constant. Its more of a pulsating sound and it all but goes away when I either straighten out the wheel or exceed 3-3500rpms in 2nd gear.

Tranny fluid was flushed about a thousand miles ago and is at the proper fill level. Power steering fluid is clean and the pump itself makes no noise that I can tell. Seems like the sound is loudest on the driver's side and for some reason I keep thinking its transaxle related. However, I have absolutely zero driveability issues and the trans works flawlessly. I'll try to get a sound clip up if I can find the charger for my camera.

 

[SHORANGERBIRD]

Liberty. is ur car still doing this??? my daughters '97 had a like similar noise. it sounded like a popping or a slapping of metal to metal sound. one tech said CV axle joint. put a LH axle in it, and it was better for a time, but again got worse. right now, car sits out back at work. trans quit.....

 

[93rev2sev]

Sounds like a wheel bearing in both instances.

 

[LJRuddy]

Yea it still does it. Its definitely not an axle issue as I just replaced the driver's side CV and the passenger is in great shape. Its not a slapping sound at all. Have you ever maxed out a hydraulic piston and heard the "screaming" sound of the fluid being forced back through the pump? Take that noise and add in some thing sheet metal flapping around and thats the sound it makes.

I hope the trans isnt making its death yell... It works flawlessly and I'd die if it pooped out out of the blue.

This wasnt a huge issue until recently when the weather allowed me to roll the windows down. Now the sound is unberable.

 

[LJRuddy]

Sounds like a wheel bearing in both instances.

I have zero play in both front wheels fwiw. If it were a wheel bearing, why would it only make the sound in second gear below 3500 rpm? I could see it making noise around a corner but wouldnt I hear the same noise if I were accelerating just as fast in 1st gear and 2nd gear?

 

[93rev2sev]

I dunno...I suppose it could depend on the amount of torque being applied. I do know that a wheel bearing can be tight and still make noise in certain circumstances.

 

[LJRuddy]

Wish there was a way I could eliminate that as a cause without having to just replace them. Thats a lot of work that I dont feel like doing

 

[SHORANGERBIRD]

Sounds like a wheel bearing in both instances.

hmm. dont know on that one, lol. it came from the left side. only under a light load, as starting to go up a hill, right before it shifted down out of OD. when it did that, the noise stopped, until it shifted back into OD. even sounded like broken motor mount that was letting the engine shift, but all of them are fine. about 2 months ago, she stopped at wally world. went in and when she came out trans wouldnt pull. i just put her in another car for now, as i just dont have time to tear into it. so it sits.....

 

[Mr Anonymous]

Tranny pump may be sucking air. Drop your tranny pan and see if the filter is dirty or has popped out of place. When you refill the tranny, add 1 extra quart after reaching the top of the crosshatches on the dipstick.

 

[venom]

Ever since I can remember, I've noticed an odd sound coming from the engine bay when I am accelerating around a turn or when using moderate throttle in 2nd gear below 3500 rpm. The sound is hard to describe but if I had to pick, I'd say its a cross between metal on metal rubbing and a hydraulic pump that is trying to push 10 degree fluid through a hose. The sound is not constant. Its more of a pulsating sound and it all but goes away when I either straighten out the wheel or exceed 3-3500rpms in 2nd gear.

Tranny fluid was flushed about a thousand miles ago and is at the proper fill level. Power steering fluid is clean and the pump itself makes no noise that I can tell. Seems like the sound is loudest on the driver's side and for some reason I keep thinking its transaxle related. However, I have absolutely zero driveability issues and the trans works flawlessly. I'll try to get a sound clip up if I can find the charger for my camera.

You said moderate but what about hard throttle? If it does it under both I would check the PS line for clearance as the stock motor mounts let the motor move around way too much IMO. You could also brake torque while sitting still to see if you can get it to do it, turning the wheel also causes the motor to shift around side to side some as well. If you can get it to do it sitting still you just ruled out the axles and wheel bearings..

 

[LJRuddy]

Sorry for the late update... I took Mr A's advice and put in 1 quart extra into the tranny. The level now sits about a 1/2 quart above the 'full' level and the sound has all but gone away. Now to figure out why I need to overfill my tranny to prevent it from sucking air...

Perhaps the filter isnt on 100%? But that wouldnt make much sense as its not exactly easy to screw up the installation of a new filter and the sound was around before I did the fluid/filter flush.