On one hot summer day the tranny stopped shifting into OD. When I arrived at home I checked the fluid and it looked like it had boiled because it was way up on the dipstick.

I changed the fluid and filter to no avail.

Also the torque converter decided to unlock at about 2200 RPM.

It only has 150k on it.

Advice, please.

Thx.

Do you have any slipping or hesitating 1-2 shifts?

Can you put your year and trim level in your signature before we go any further?

There are distinct differences in transmissions from year to year.

The transmission doesn't have any hesitant shifting. Under a hard acceleration it does shift a bit rough. Under normal acceleration it shifts just fine.

It is the SE model. Not sure about the trim level but it is all black (even the Pontiac emblem on the front), has a spoiler and ground affects.

We need to know what YEAR. 19__ SE.

At the top of this screen, click on profile. goto the bottom where it says Signature. Please put your year and trim in the box. This will let everyone know what kind you have. As Will has already said, different years have different transmissions. It helps us figure out what is wrong with your car.

It is a 98 SE. L36 engine.

Did you use synthetic fluid?

What does it look like NOW? Color, smell, level?

Does it ever shift into OD, or was it just that 'one hot summer day'?

Do you have a check engine light? If so have you had it scanned?

What RPM do you run with the shifter in OD, running 65mph on the freeway with cruise?

If it NEVER shifts into OD, I'd be getting a scantool on the car to determine if the PCM is even requesting TC lockup. There may be a non-trans related sensor or condition preventing it.

Any speedometer problems?

Willren:
I use syn blend oil
No unusual smells
Has never shifted into OD since that hot summer day
No codes
I always leave it in OD, and run it at freeway speeds (70+) and it never shifts to OD

Mike1995:
No speedometer problems