Auto Tranny Gets Stuck in Gear

saturn
transmissions

#1

My wife and I drive a 2001 Saturn L200 with a 4-cylinder engine, an automatic transmission and about 100k miles on it. It has been the most dependable car we have ever owned. But the last few summers, when it gets hot (here in Oregon, that’s 90+ degrees), the automatic transmission will act up every once in a while. What happens is that the transmission seems to get “stuck” in a particular gear. For example, the first time it happened, we were running down the interstate, and pulled off at an exit and stoplight. When we tried to get going again, it bogged down and acted like a manual transmission that is in 5th gear instead of 1st. Similarly, if you are going along a mountain round at 20 mph, it will get stuck in a lower gear and you hit the highway and the car never down-shifts. The solution to the problem is very simple… put it in park, turn the car off and restart it. When you put the transmission in D again, it sort of “slams” into gear, but than all is fine. Unfortunately, it has never happened close enough to a mechanic fop us to baby it into the shop and there are no codes in the computer afterwards. So, it seems to be electronic, as restarting the car solves the problem and it also seems to be heat related. Any ideas? Thanks in advance.


#2

Transmissions are a complicated system of gears and unless you have the experience this all turns into a guessing game.

We have a trans specialist on this forum that could answer your problem correctly, but don’t be surprised if he doesn’t answer with some questions of his own first.

I could take a guess at the ‘slams’ problem but I won’t.

Lets see if Transman18 is around.


#3

Its would says its a computer system. The mechanic I use is Giddy-up Go Mobile Mechanic he will drive to you on the side of the road and scan the system and tell you what sensors acting up. tell him Marc’s Computer Solutions sent you.


#4

Alright, 2 years later, the problem has not shown up again. Car now has 125k miles on it and runs great. However, recently I noticed that the engine rpm drops to 1000 at highway speed when I take my foot off the accelerator. I then have to let the engine spool back up to about 2000 rpm (normal highway rpm) to get acceleration. It used to be that the engine rpm would stay elevated even while coasting and throttle response was much quicker. Is this a sign of an automatic transmission needing a rebuild or something like a solenoid needing repaired? I understand you can’t “diagnose” a problem on a forum, but guidance on the urgency of getting this looked at and general expectations to extent of damage would be greatly appreciated heading into the repair shop. Thanks.