Transmission Stops Shifting with heat
I've just read through every thread with a tranny problem here and didn't see this here.
On my way back from Raleigh, NC over Memorial Day, my girlfriend was driving through the first stage of the mountains. The SES light came on as the engines surged a little bit.
We stopped at the next rest area to see what happened and to give the engine a short rest. A half hour later, we pulled out of the parking space (R) just fine, but shifting to drive (O) made the engine struggle at pushing the car until it got up to speed. The Rest Area has a slanted road area, so I didn't think anything of it. The light was off.
Over the next six hours on the way home, the transmision was running 3-3.5k at speeds of anywhere from 60-85mph. (It was NASCAR Traffic, after all.) Going 85mph at one point I was passed by a motorcycle going at least 95 who would slow down in the area between lanes, since there were cars on both side, to yell at the vehicles on the left about moving to the right lane... He almost got run down by a construction truck...
Anyway, when we stopped at for lunch 3 hours into this 6 hour drive, my temperature guage showed about 200°. We tried to park in as much shade as possible. Transmission fluid level was fine when we took her over to the cas station. Color was red, too. I had a fluid exchange last spring and then a seal and filter replacement only a couple months ago, so I didn't expect a problem. I also replaced the Cat just 6 weeks ago, so engine cooling hasn't been a problem since.
Ever since, when the car gets to operating temperature, I can mostly expect that once I get up to a speed around 40mph, the transmission won't shift down. I can shift it to 2nd (D2) and move fine, shifting when I hit the right speed/tach. When I let it cool down, it starts fine.
I am going to take it to the store that can read my codes in a few minutes, but I thought I'd check in here to see what might be. I suspect that I have something gunking up my transmission cooling lines, causing the fluid to get too hot and lowering the vicsocity so that the automatic transmission doesn't know when to shift due to expansion or something. Or something I could never guess is happening. I suppose the PCM (which I replaced the same weekend as the Ignition module) could be overheating, too.
One note that I don't believe to matter... I had to replace my Ignition Module in Mossy, WV on the way down when my ignition stopped going uphill on Rt 77. I pushed it about a half mile to within 100 yards of the service station before I couldn't push anymore. That'* my second replacement. I don't know if that has any relevance, but it was only a couple days earlier, so who knows.
If you have any suspicions, post them. I'll have the code(*) in a couple hours.
It figures that all these problems would come just shy of 195,000 miles. I really want to get those 5k out of it.