Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

1993 Toyota Corolla runs cool and doesn't shift into O/D

I just picked up a Toyota Corolla with a 4 cylinder and auto tranny with O/D. The car runs well but the temperature guage only slightly moves (maybe goes up about 5% from a cold start).

I’ve never had a Toyota before so I don’t know where the temp guage should be but I would think it should be somewhere in the middle. When I shut the car off, the needle falls just a little to get pegged out at the bottom.

I’m pretty sure it’s either a missing or stuck open thermostat but I haven’t looked at it yet. The heater works, but it only is warm, not hot.

When I bought the car (days ago, of course), it was warm and it shifted easily between all four gears.

Last night, I noticed it stayed in third gear when I drove a short distance on the highway. I stopped at a gas station and left it running. When got back on the highway, it shifted through all four gears.

Today, it’s about 2 degrees and it won’t go into fourth gear again.

Does the temperature of the vehicle prevent the car from shifting into 4th/OD?

Thanks. Any info would be great.

I’m not familiar with the Toyotas but in a Buick anyway, if the car has not reached operating temperature, the trans will not go into the overdrive gear. The first thing to do would be to take care of the cool engine temp. Most likely need a new thermostat, and go from there. If an engine doesn’t reach normal temps (195 or so), it will be running far too rich and cause other problems.

So good to find out O/D is also caused by temperature.

Plan on changing Thermostat when it’s above 10 degrees out.


Bing means that when the engine isn’t up to the proper operating temp (195 deg, if that is the spec of the t-stat) the tranny cooler temp won’t be equal resulting in a sluggish shift.

NOTE: this is not to say the OD doesn’t have another fault causing the no-shift.

I have an '04 Toyota Matrix XR with the 1.8L and it has a 195 deg t-stat but I sometimes have the car up to 50 mpg before full operating temp and it has no problem shifting into OD.

I don’t know if your '93 has an OD shut-off button or not.

Mine does and I have found that if I’m not careful when shifting the (side mounted shift release button) shift lever that I press the OD shut-off (immediately below the shift release button) and leave the tranny in third until I realize what happened and press to release the lock-out button again.

When the car is in its half warmed up state feel the hose to the top of the radiator. If it’s anything but ice cold then the thermostat is missing or not closing.

I think Bing is 100% correct. replace the thermostat!

Yes, your 1993 Corolla will not shift into 4th until the engine reaches a certain minimum temperature. If the thermostat is bad and the engine stays cold then the transmission will stay in 3rd on the highway. My 1995 Toyota Previa was like this too but I never had a thermostat problem so once it warmed up it shifted fine in the winter. In the summer it shifted fine right away.

Thanks all.

It had a faulty thermostat stuck open. Replaced thermostat (why, in God’s name did they have to put it right under the distributor?) and the temp went to normal and no more o/d problems.

Thank again.

Thanks for letting us know the result.