1994 Grand Prix Tranny problem

[Chief Wiggim]

I few days ago my tranny started acting up. I'm not sure if its slipping or its starting out in second gear,it acts like I'm in second gear start. The speed odmeter has jump a couple times around 25mph. It doesnt shift into passing gear either. I havent ever changed the tranny oil and filter and the car has 144,000 miles. The oil is full and doesnt smell. It does seem alittle thin. Could it be the speed sensor?? or just need to change the oil and filter?? The heat gauge will climb realy high like the tranny is getting hot and after I get rolling down the road it drops to normal temp. Any Ideas??

[GTP Dad]

Unfortunately, I think you may be beyond the fluid change and refill stage. You can try it but I think you are probably not going to have good results. As for the heat issue, the transmission could be causing this issue because the engine is having to work so hard to get the car up to speed then once you get there the engine workload decreases and the temperature drops back. You may want to check the coolant as you may also have a leak in the trans cooler inside the radiator may have gone bad and you are getting coolant in the transmission or transmission fluid in the coolant. Neither is a good thing.

[Chief Wiggim]

I went out today and drove it around the yard and it seems fine now. I only work about 2 miles from home and I think i'll try it again tomorrow and see if it happens again. If it doesnt act up on shot rides than I will drive it til it doesnt go no more. I'm still going to change the oil and filter in the tranny this weekend.