I was wondering if any of you could give me some advice, my Bonneville will not shift into gear until I warm up the car. It usually takes two minutes of running the engine for it to shift into reverse or forward. It did not do this until I had the fluid changed about four months ago. I put some lucas transmission additive in it but it did not help.Also it wants to idle high enough to drive 70 down the road with out touching the pedal, I can turn the Ac on or sometimes the heater and it will idle back down.

do you park on a hill?
i do and in our cars it has something kinda like an parking-brake for our trannys... if you put on the parkin brake it might be a little easier, but it jus takes more force until it warms up... anyone else?

It is usually parked level and in a garage

i got nuthin then... i tried! sorry man, im pretty sure someone on here can help u tho... good luck

When does it idle high, when you just start the car, or anytime? How high is high (in rpms)?

Sorry to ask the obvious, but you didn't mention if you checked the fluid level. If it'* low and cold, you could have those symptoms. Be sure to follow the owner'* manual on how to check it. I had a Chrysler minivan that was doing that, and I had been checking the level incorrectly and it showed full, but when I read the manual, and did it correctly, I was seriously low on tranny fluid.

I did check the fluid level with the car running and level, it was full. This morning I cranked it up and waited the usual two minutes and it shifted into reverse. I was going down the road and there is no need to touch the gas pedal it will run about two thousand rpms which will get you going about 70. I shifted into neutral and it read 3600 rpms. After about twenty minutes ( the temp had reached 180 after ten minutes) I shifted down into drive from over drive and back into over drive and the RPMs dropped down to normal levels. When you first start the car it idles fine, it slowly creeps up the idle going down the road. When you get up to say fifty or so you can pull your foot off the gas and it will continue to accelerate.

What year and model is that? Put it in your signature. We really need to know this, and there'* too many cars to keep track of now!

Have you scanned for codes yet? It sounds like a sensor problem for the idle problems.

No I have not scanned for codes, I am taking it back by my mechanics today after work for him to do that. Any ideas on the transmission problem?

Believe it or not, my thoughts are that it'* somehow related to your high idle. This is a new one on me, so I'm gonna learn with you. With freaky unknown crap going on, first step is the codes. We'll get it from there. We always do.