'97 850 NT Automatic: Drives quite normally for up to two minutes, then trans starts to slip and soon disengages. Turning off engine for approximately a min or more seems to reset whatever is causing this and the scenario repeats itself. Seems to shift normally through all gears. I've heard of a "limp home mode" but I'm soon unable to even limp!

Just idling in the driveway, everything sounds normal for a couple min. then a whirring sound develops at trans. end of engine. I've drained and changed fluid, filling slightly under, at, & over the full mark but this affects no change.

Could this be a faulty shift solenoid, or PNP switch? Sure seems to be related to either temperature, pressure, or some intermittent electrical supply thing.

This whole problem developed completely out of the blue while driving to work.
TD

 

Do you have a check engine light ??

Do you have the dreaded transmission "up arrow" flashing ??

 

Thanks for the response. No check engine light, no code show with my code reader. Had the flashing arrow only during one episode. Trans shifts too normally for that couple mins for me to think its a serious internal problem. TD

 

Have you checked the level of your ATF, hot and cold.
Also is it a cleanish red color or burnt brown looking?

 

Transmission fluid is OK. I did drain and refill as my first plan of attack but it made no difference. TD