Okay, so about 2-3 weeks ago I had a tranny put into my Neon. Up until a few days ago the car was running perfect,no weird issues, noises, or leaks. Now the car has developed a very subtle noise, not exactly grinding (as I remember hearing it from the old tranny), more of a whirring or whine. The past 2 days or so I could only hear the noise in park or neutral. I tested to see if the noise would increase if someone else pressed the gas a bit but it stayed at the same level. However last night I was sitting in a drive thru and noticed the noise was there in drive and sounded like it was slowly going away and it did after about a minute, but throwing it in park brought it back immediately. Jump to today and the noise is present in all gears, at least after driving awhile, didn't really check before leaving as I was in a hurry.

I've checked the fluid which is topped off, red, and doesn't smell burnt. No engine codes have popped up since we put it in either.

The tranny is used but only has around 35k miles on it. This has me thinking is probably a bearing of some type, especially since the sound doesn't increase with acceleration like my old trans did. That being said I am no mechanic but I'm trying to get one to check it out today or tomorrow. Figured I'd give it a shot here because it never hurts to have a second opinion.

 

Did you check for codes with a scanner, or just in the cluster? I ask to double check because transmission codes don't show up in the cluster. A whining noise could be from a wide range of problems. Just making sure there isn't a code that could help narrow it down.

 

Both pulled nothing. I've been driving around and the car shifts smooth for the most part. It can be a little rough under hard acceleration but nothing worrying. Haven't encountered any slipping either.

If I had a floor jack I'd check underneath for noises, but all I can get is its definitely on the driver side. Under the hood all its loudest near the airbox/tranny.

I did read online that starters can make these kinds of noises but there haven't been any signs of it going bad, always starts up right away and I never hear any excess clicking noises.