Shifting problems-1990-Celica ST 1.6-4A-FE, Automatic

[fistofmeat]

The car shifts great from 1st to 2nd.
When it try's to shift into 3rd is where the problem starts.

It will get to 50 MPH then start to rev real high and the thermostat needle will drop to the top of the last three bars and stay there.

This happens intermittently some days I can drive it all around the city and not have the problem. When at a red light the thermostat needle goes back to it's proper place to the center needle o the gauge?!?!

I have been told that it all looks like a sign of a bad transmission. Specifically a torque converter. Or a stuck valve inside the transmission.

I recently have changed the starter (not symptom related). Changed the spark plugs from crappy autolites to E3's.

New OEM spark plug wires, caps and rotor. New air filter, new transmission filter and fluid. Have the OEM fuel filter just have not got around to installing it.

New Mobile 1 oil filter and top o' the line Mobile one oil. End result the car now starts every time I need it to (another story from earlier this last summer) and runs a little bit better, however the shift from 2nd to 3rd and the high revving off and on still persist.

When it does decide to work (shift) normally the cars still seems like it could have more power as well. In any case it just turned 100K and maybe needs to be put out to pasture as I do not enjoy getting nickle and dimed to death.

Any feedback, suggestions or possible solutions is greatly appreciated. By the way this is my 1st post to any online forum ever so I apologize up front if I missed any formal online chat/forum etiquette's.

Have a great day and Happy Easter.

[Bitter]

change the thermostat.

[93celicaconv]

I think Bitter is right. Your Celica has an shift interlock based on coolant temp. It sounds like, at times, your thermostat gets stuck in the open position, overcooling the engine, the coolant temperature drops, and when it gets too cold, it engages your automatic transmission shift interlock, preventing it from shifting into higher gears and locking the torque converter, as it should.

I guess I don't know what your mean when you say your temperature gauge "drops to the top of the last 3 bars" means. Does it drop far enough that the needle is pointing to the "C" (or cold) mark when being driven?

Get an OEM Toyota thermostat and replace your old one and let us know if this solves your problem. I think it will.

I would recommend a thermostat change.

[fistofmeat]

Hey Bitter and 93celicaonv thank you both for your quick responses I truly appreciate it. : )

I will change the thermostat and keep you posted. To 93celicaconv "drops to the top of the last 3 bars" I should have been more specific.

I mean the needle does not drop all the way down to the bottom of the gauge. It just hovers over the top of the third ticker bar on the gauge. I hope that is clearer...again thank you both sooooo much and have a good Sunday.

[Bitter]

yea, what happens is the A series engines/automatic transmissions will lockout 4th gear until the engine coolant reaches a certain temp. this is to get the engine hot faster by keeping the revs up and also reduces emissions and wear on the engine.

thermostat sticking open means the engine is getting over cooled at high way speeds due to airflow through the radiator. around town its not as much of an issue and you never notice the symptom of weak heat because of where you live.

engine gets to temp, 4th gear is allowed, engine gets cold again and 4th gear is turned off again. you'd have bought a transmission and had the same problem, whomever told you that you needed a trans either doesn't know alot about imports (or cars) or didn't have all the information we have here (like the engine temp stuff).