Problem going into Drive or Reverse from Park when cold..

[alkemist]

Hello,

One of our Buicks, a 1993 Lesabre is going over 150k now without any previous problems. But unfortunately a transmission related issue recently came up.

When I cold-start the car in the morning without letting the tranny warm up before going, transmission simple fails to switch into Drive or Reverse.

Once again, the vehicle Im describing had not had any previous conflicts, despite its high mileage. Probably due to very calm style of driving this car was used for.

Any help for resolution of this issue would be great.
Appreciate it.

[Racincc85]

Have you checked the fluid level? It may just be low. Also, how is the color of the fluid?

[alkemist]

Tranny fluid - OK
Transmission filter and 7 Qts of fluid from the pan was changed less than 15,000 miles ago. Id like to point out I purposly did not flush the system to avoid any future problems.

Now I noticed what seems as a coincidence to me, but maybe you can help me out.

The problem described occured at the same time with a strange noise from cylinders, when I filled the car up with 87 instead of 89, which I always used. The "strange noise" I am talking about came from cylinders as if one one them was being misfired. Not sure about that.

But what bothers me is that transmission issue happed when I filled up the car with 87.

Following the problems, I mixed 87 with 93, to sort of correct gasoline mixture in the tank toward the normal one I always used.

Ever since I added that 93 and went back to 89, problem seemed to subside.

Can ocaine # make such a great difference on the transmission behavior. Or is it the sensors messing around with it?

[TheSilentChamber]

You should be able to run 87 in that car with no problems, and that should not effect the transmission. Does it simply not go into gear, or is the shifter very hard to move? I had a 96 regal once that when cold outside the shifter was very dificult to move down into gear- never did figure out what it was.

[UncleBob]

octane and the tranny have about as much to do with each other as the tranny and the cars color.

If you were only complaining about hard shifting, for example, then it might make some sense....a misfire can cause odd problems because the computer gets bad readings from many things when that happens. But the tranny should still engage no matter how badly it runs, I would think.

[alkemist]

Got it. Well just as I thought this is one big coinsidense Im trying to resolve before it gets cold outside. Working tranny is #1 priority.

The column shifter moves just fine, but tranny simply fails to drop into gear. Maybe some sensor is going?