94 olds problems with transmission, losing 4th gear in hot weather

[fatbob]

I have owned and driven a 94 olds cultlass supreme for the last 6 years. I have about 108,000 miles on the car and it has the V6 3.1L engine.

 

During the last couple weeks the outside temps have been very high (90's to 100's) and I've been on the road a lot. When the outside temp is hot, if I drive over 65 to 70 mph, I will lose the 4th gear. The transmission will drop to 3rd gear while driving for no apparent reason and will not go into 4th until I pull over and let the car cool off. I do not have this problem at night at all (or if the outside temperature is otherwise cooler). Also, I've noticed a soft but high pitched noise coming from the transmission when coasting recently. (I'm not sure if this is new or not, I may have just noticed it now that I'm paying attention with the radio turned down).

 

Two years ago the engine was starting to overheat and the transmission did the same thing - switched into 3rd gear unexpectedly and worked fine after letting the engine cool. The engine overheating and transmission issue was fixed with a new radiator. The engine is not overheating this time around according to the temp gauge which seems to be working fine.

 

I've been reading these formus and seen some people mention similar problems but none exactly the same so I thought I'd throw this one out here. Is there anything I can do to try and keep the transmission cooler? Will changing the fluid and filter help? I've not changed them since I've owned the car. The original owner was a mechanic, but I'm not sure if he ever changed the fluid. I did check the fluid level and it seems to be fine. Is this just an omen of impending transmission failure?

 

thanks,

Steve

 

[Crazy K]

I seem to recall reading in the factory service manual that the tranny will drop to a lower gear to prevent damage if it gets too hot, probably because it would be less stress on the transmission, and would generate less heat. thats what came to mind with reading this. but I'm not sure if thats where I read that.

 

whens the last time you changed the trans fluid?

 

May i recommend adding a tranny cooler?

[Mach 5]

Id say do a trans fluid change and maybe adding or checking for clogs on the original.

 

Don't just do a change. Actually flush the entire system just to make sure.

[fatbob]

Thank you both for the reply.

 

I can't remember if I changed the fluid. I think I did when I first purchased the car 6 years ago at 66,000 miles. I haven't recently. I plan to have that done soon - if I keep the car.

 

I'm a bit reluctant to do a flush only because I keep reading that can cause problems on a tranny with high mileage. You think it would be okay at 109,000 miles?

 

thanks again,

Steve

[Crazy K]

I would change the filter and replace only the fluid that comes out when you do that. I would not do a full system flush like aamco advertises on tv. Some of that crud that might be floating in older fluid is part of the reaon the tranny works at all!

 

now, that said, a 94 cs has the electronic transmission, it could be a seloniod failing, or a bad wire..... meaning one of the selonoids is worn out, shorting out or just plum loosing power.

 

try removing the connector that is located on the front of the tranny, near it's top by the radiator/air intake hose area... clean it, grease it with dielectic grease and hope that fixes the problem.

 

 

[Dark Ride]

is it switching to 3rd or is it in OD just that the TC unlocks?

 

Next time it does that shift to "D" and see if your engine revs up higher.

 

If It does then its your TC lockup solenoid,

it could be going bad:

Or:

Your transmission could be overheating. I just fixed this problem by installing a transmission cooler. The transmission cooler thats built into the side of the radiator gets plugged (sort of) and doesn't cool therefore the trans temp soars.

 

Check out my updated thread to see if thats your problem

 

Mitch

[ns87]

fatbob: When I bought my car at 107,000ish I had the fluid flushed. Twice actually and it was fine. But its acted better when I changed the filter and fluid several times myself

[19Cutlass94]

How does the fluid look? Its not going to hurt to change the fluid and filter. Id deff get a reading of what the tranny temp is operating at because if its too hot, youll need an aux tranny cooler.