I recently changed my TC fluid a week ago myself with diaqueen and noticed the next day that it was making a mechanical whining noise in the lower center of the car at over 2K rpm at speed. Been reading all the forums and came across lots of whining noises ranging from barely audible (but no real problems) to louder than radio at full blast (obvious TC death). You can hear mine but it only gets a lil louder as you go faster. You don't hear it when the clutch is depressed though. Should I get the dealer to do the TC fluid change again? Just how loud is the whining everyone is getting when they first notice the TC is going bad? I'm at the dealer right now and having them inspect the underside of the car.

 

it's like a whirling sound that gets louder the faster you go... the worst it gets, the louder it gets

 

hmm, mine sounds similar to turbo whine than a whirling noise.

 

possibly boost leak?

 

yeah sounds like the tc going... mine went like that... if it gets very loud at 80-100mph ... go to the dealership and have them listen to it.
make sure you use only Mitsubishi fluids on the tc.. They will give you a hard time otherwise.

 

according to boost gauge it holds steady but can you tell a leak just from boost gauge alone? i had dealer check it out and documented. worked order said they checked levels and they were ok and they found nothing wrong with anything. i put diaqueen in the tc but only thing was i changed the fluids myself.

 

The gears in these things make noise because of the cut. If the gear whine changes picth as you change gears, it is normal. If you hear a whirring noise, it's normal. If the whine gets louder when you go faster and sounds like a vacuum cleaner at highway speeds, then your tc is going.

 

kool. thanks for clearing that up. prolly is a boost leak then.

 

I hear a whirling noise as I'm slowing down in neutral. It's from about 45mph to stop. Been doing it for about 20,000 miles now.