ericch23

Hey everyone Im new here and Im wondering if someone can help me out. About 2 weeks ago my 99tahoe started vibrating when I come to a complete stop or if I am going under 5 mph. It kinda sounds like a motorbike engine but not as loud coming from under the hood. It does this when I completely stop or coasting to park and also going in reverse. WhenI put it in neutral or park the noise completely stops so Im thinking it might bea transmissionproblem (hope not).Has anyone experienced something similar or have any advice? Thanks.

Throttle

Some things to try:
Leave it in park and rev the motor then let it idle down... if it is smooth your engine functionis ok and is time for the next step.

Drive around your neighborhood, find an out of the way place (like a quiet intersection) and get going about 15-20 mph then slip the truck into neutral and use the brakes to stop....see if you still have a vibration when your coming to a stop. If you do it is probably your brakes.

If it doesnt vibrate then speed up to 15-20 mph, leave it in Drive but dont touch the brakes... let the truck slow down on its own... try to notice at what speed it starts to vibrate.

The object is to isolate each part of the truck to see what is causing it to vibrate.

ericch23

Thanks for the reply I tried what you said and I still couldnt figure out anything. See its fine when Im coming to a stop, its once I come to a complete stop and im sitting there with my foot on the brake pedal a noise will start, I noticedI dont feel much of a vibration but it sounds like one likea "trrrrrrrrrrrrrrrrrr". And again it only happens once I am at a complete stop (like a red light) and only in gear, the noise stops in neutral and park.

RonH

Maybe you can have someone standnear the front wheelwith the hood open while you duplicate the situation to see if they can tell where the noise is coming from.

73shark

While you are stopped and it's making the noise, try turning the steering wheel lock-to-lock and see if that has any influence on the noise. If it does, then try it again w/ it in Park and see if the noise comes back. If it comes back, then it might be P/S pump or the engine.

loulblades

Kinda sounds like a torque converter to me.

Throttle

Alright so its less of a vibrate you can feel and more of a noise... check the fluid level in the transmission.

Are any of the shifts rough? like from 1st to 2nd or from 2nd to 1st?

Do you have what feels like a loss of power or a slipping that occurs if you step on the gas real hard?

While your stopped if you put your foot on the brake real hard and then step on the gas a little does the noise get worse or go away?

Trans problems usually have rough or non-shifting gears or a loss of power under heavy acceleration.

Check the P/S unit like 73shark suggested.

If all that works out alright, the only thing I would do is check all the fluid levels to make sure things are ok and just keep driving it. You could spend forever chasing every littlethingbut ifa part going out its going to die anyway, might as well drive it in themean time so your not spending a bunch of money on things that are not the problem.

One more thing... does the noise happen when you first start the engine or does it have to warm up first?