Hi..this is my first post, though I read this forum almost daily.

I need help diagnosing a resonating whining noise on my 95.5 Rodeo with an automatic transmission and 68k miles on the odometer. It occurs around the 2000 rpm mark (where the transmission normally shifts to the next gear). There is no whine before it reaches this mark and the noise disappears beyond this point. The whining occurs in any gear and even when the car isn't moving (sitting in neutral or park and revving engine). It is a high pitched sound that has some resonance and a slight vibration.

this problem occurred after I brought my truck in to the dealer for some work. The starter, timing belt, waterpump, tensioner, valve cover gasket were replace. Also a 60k mile service was done. This includes a transmission flush, among other things. I'm worried that the transmission flush may have done some damage here. (I know I should bring it back to them to let them deal with it, but it is hard to prove that they did something wrong)

I've since had a mechanic drop the transmission pan and replace the filter, but this didn't help. I tried adding lubegard red to no avail. Is this whine most likely from the transmission or the torque convertor? Could it be something in the engine instead? Suggestions?

BTW, I tend to baby my vehicles so the car is well maintained from birth. The transmission was flushed before at 30k miles. The fluid always looked good between flushes.

I doubt it has anything to do with your transmission (especially since you state that it happens when in park)

Could be a loose heat shield vibrating.

Anthonyn, it sounds engine related instead of trans related. Look at your tach. At what rpm does it start whining at? Does it whine from that rpm upward to the rev limiter or is it just over a few hundred rpm? Does it always occur at the same rpm?

My initial thought is that it's a partially plugged convertor. You mechanic has tools to check for that. I've had that happen to me once and it made a nasty whining noise at higher revs. If the noise always happens at the same rpm and it only occurs for a few hundred rpm, then it sounds like a loose heat shield. If it always happens at the same rpm, then something is loose(probably in the exhaust hence the heat shield theory) and the vibrations come into resonance at that rpm. Depending on what's loose, it could vibrate at a high enough frequency to sound like a whine. Good luck.

Alin

As per the feedback I recieved, I climbed under my rodeo and tried to bang on the heatshields, exhaust and just about everything I could see, and did not find anything obviously loose or rattling around. My exhaust seems to be rock solid.

Here is another thought though. This whine always occurs at the shift point which is around 2000 rpm plus or minus 100 rpm, regardless of what gear I am in. Once it moves below or above this shift point, the whine ceases. I would think that if it were something loose, It shouldn't be only at this one point regardless of whether I'm in 1st, 2nd or 3rd gear.

If this is something internal, does the fact that it occurs in 'driving' gears as well as PARK and NEUTRAL rule out the torque convertor, or implicates the torque convertor? Can I rule anything out based on this observation?

Well take her out more often <img src="/forums/images/graemlins/notooth.gif" alt="" />

OK, couldn't resist and (unfortunately) I have nothing to offer (no auto experience) except for a friendly BTT ...

I'll tell you what. Pop you hood..and use the throttel control on the throttle body to listen from under the hood. If you hear it clearly there, get a fiend to help you. Get a broom sitck, thats made out of wood, and ithout the broom. Have your buddy rev the engine to where it makes the noise, and hold it there. You will use the broom stick the touch various parts of the engine, i.e. water pump, alternator etc. Place the stick on your head, like behind you ear while the other end is on the accsory you are checking. I know it sounds funny, but it works, the wood actually tramsmits the sound (and vibration) to your head, which you will hear clear as day when you find the part the is making the noise. I suggest starting at the front because, with a new belt tensioner and water pump, it is possible that there are loads on something that wasnt replaced adn should have been, or what ever, causing the earing to start singing, letting you know that its time to replace them(or accessory). I can describe more clearly if you want...BY THE WAY...be carefull where you put the stick, you know, hte other end will be around your head, dont let it hit a pully, or something, because, let me tell you, it will hurt. Hope this helps....

Chase

I know this doesnt sound to inteligent, but carefully done, is very effective at finding noises..Ever heard of a mechanics stethascope?....

Chase is right about that.. I had a whine I could'nt locate & used the old stick to ear. Turned out to be a belt pulley w/a bearing going bad. I admit that before doing this I pulled my Rodeo into my garage & shut the door! <img src="/forums/images/graemlins/coolg.gif" alt="" />

Ok. I did the wooden stick stethoscope technique and now I am pretty convinced it is not the transmission (whew!), but rather something in the engine. I couldn't find a broom, so I used a closet dowel. It was about 6 feet long, so I looked like a Jedi knight sparring with gremlins in my engine. Given how long the dowel was and the lack of space in the engine compartment, I could not pin-point the exact location of the whine. But, with the dowel, I could hear that the whine is actually made up of distinct "voon, voon" sounds, which leads me to think it is something rotating (timing belt tensioner, pulley etc).

I have an appt with the dealer to have them check it out. Thanks for all the tips. I somehow had it in my head that this was a transmission/torque convertor issue, but you folks steered me to a better direction.

OK, someone else started it.
"Leave the kids at home when you drive it." <img src="/forums/images/graemlins/wink.gif" alt="" />