Vehicle:'99 Merc. Mountaineer Monterey
5.0L V8 auto, o/d , 2WD

Summary:
Being resonably mechanically inclined(I have replaced numerous engines, transmissions, clutches, etc... in my RX-7, only because I drive it way too hard), I would like to know if the TCC solenoid in a '99 mountaineer is very easy to replace.

Symptoms:
Driving home from work the other day, I noticed the 'o/d off' light blinking, and also noticed that the TC did not seem to be locking up when I reached crusing speed, so the first thing I did was a quick search on the web. I found this link:

http://groups.google.com/groups?q=o/d+off+light+blinking+mountaineer&hl=en&lr=&ie=UTF-8&selm=8jvneo%24ev3%241%40nnrp1.deja.com&rnum=1

and this seems like it might be the problem. I spoke with a friend of mine that is a full time mechanic(but not a transmission guy), and he said alot of times the TCC solenoid is easily accessed by removing the transmission fluid pan. Is this the case with the Mountaineer?

Thanks,

Jimmy

 

I would pull the codes first. You may be barking up the wrong tree. You can either buy a code scanner, or get it read at a dealer/repair shop. Also, If you have an Autozone nearby, they will read them for free.

 

I had the same problem on my 95 EB.

I also noticed that the engine RPMs were jumping around a few hundred when the O/D started to flash.

I took it to the dealer and they found the the Throttle Position Sensor (TPS) was bad. The sensor fails in a way that simulates intermittent full throttle to the transmission. This was causing the torque converter to unlock/lock repeatedly.

The sensor is $50 and it is aboslutely the simplest component to replace. It is right on top of the engine and one of the first things you see when you open the hood. There is a test procedure for the TPS if you are unsure.

 

 

Well the light stopped flashing the other day, and the TC is locking up properly again, I will go ahead and get the codes read though.

Thanks,
Jimmy