Just a brief history: I replaced the Engine and trans in my 95 SE with a unit I got from the Yard. After it was back together I had a whining type noise which sounded to be coming from the trans side pan area when the trans was in Park. The noise seemed to go away when in drive or reverse.

I decided to replace the transmission with another unit that was rebuilt (gm cert) sticker. After putting it all back together the noise remaind .. Maybe a bit less then the other unit but it is the same whining type noise and only in Park or neutural.

I replaced the side pan, filter, and three seals on both transmissions before putting them in the car. The motor seems to run fine (50K) miles on it ... I did replace the rear seal and oil pan gasket on it before installing it.

I checked all the vacume lines, replaced most of the fittings and lines. The car has no error codes and the transmission seems to run fine ... Just have this whining sound when I put it in park. I did check the O-ring on the PCV valve and it is in place.

Anyone have any ideas??? Anything I should look at? Any ideas on how to find the problem??? Please help!!!

I retightened all the bolts and checked for exhaust leaks but everything seems fine.

Tell us about the torque converter. Is it from your original trans?

I replaced the Torque Converter with the transmission. Both replacement transmissions came with torque converters ... I had this same noise twice after replacing the transmission.

My best discription of the noise is sort of a whineing , medium to high pitch ... It seems to follow the engine rpms until they hit around 2k then it goes away. Also, it is only present in park and neutural ....

I'm stumped.

could it be the intake noise? i hear a sorta squealing(?) noise on mine...i only notice it when i accelerate from a stop...just an idea

doesnt sound like its coming from the trans if both did it although the change in engine rpm in neutral could cause it to become louder.
This is very hard to diagnose without hearing it. Try getting a mechanics stethascope and listen under the hood in different locations until your hear it get louder.
A guess would be a vacuum leak or something with the airbox.

That'* what I thought also about the vacume leak ... I checked all the hoses and fittings and they all seem tight. I agree with you that it probably isn't the transmission. I will take a better listen again tonight ... possibly with a stethescope if I can find one.

Could it be anything with the engine itself ... it is a replacement engine from the junkyard??? It seems to run fine though.

I took the serp belt off and it still has the noise so it isn't anything with the pullys.

Help .. I'm stumped and neeed some ideas!!!!!

If you suspect a vacuum leak, then spray the hoses down with carb cleaner, surges/stalls indicate leaks...

It sounds like a pulley issue to me. I had the same noise on my 94. It was constant to the engine rpm but never went away. It ended up being the inner pulley where the two pulleys are. I want to say idler pulley???

I purchased the stethescope today at Sears and from what I can tell the noise is coming from the area where the drivers side axle comes out. Actually when I put the scope on the trans case in that area I only hear something faint ... when I put the scope on the axle itself I hear it 100 times louder.

As I said before this is my second transmission that I put in with the same noise. Could it possibly be the snap ring on the axle spinning or something stupid like that ???? I did replace that axle seal when I installed the transmission.

Any thoughts???

Thanks to everyone in advance ...