1993 Toyota Corolla Engine Temp

1993 TOYOTA COROLLA
85,000 MILES • 4 CYL • FWD • AUTOMATIC
Avatar
JUSTME3040
  • MEMBER
  • 3 POSTS
Hi, I just had the thermometer in my car replaced because it was faulty and the temp gauge was not moving. This was a problem because the computer in my car prevents it from shifting into overdrive unless the car is warm enough. As you can imagine, driving on the highway in 3rd gear is a HUGE waste of gas (5-6k RPM). The problem I am having now is that if I leave the car in the driveway for a while it warms right up, but then as soon as I start moving (mostly on cold days), the gauge drops to cold very quickly. The highway is down the street from my house and if the gauge is halfway up its about a 50/50 shot whether the car will stay warm enough by the time I get to the highway for the O/D to engage. Is there something else malfunctioning in my car, and if not, how can I get my car to think it is warm enough...I'm getting like 15mpg on the highway when it doesnt shift which is terrible for my car.
Thanks,
Justin
Jan 17, 2008 at 5:39 PM
Advertisement
Avatar
RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
In Toyota's the coolant temperature sensor has to reach a certain temperature in order to tell the computer to engage the overdrive.-try replacing it.
Jan 17, 2008 at 6:04 PM
Avatar
JUSTME3040
  • MEMBER
  • 3 POSTS
Sorry to bring this back so long after the original question, but I had my temperature sensor replaced, and now my temp gauge will heat up when the car is on, but only when it is sitting still. Shifting into overdrive happens now, although it is very sporadic. Is the coolant temperature sensor a different sensor? Were they both broken?
Mar 11, 2008 at 8:35 AM
Avatar
RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
The computer uses the coolant temperature sensor for fuel enrichment and overdrive purposes- this sensor is located at the thermostat housing and also send the engine temperature to the gauge.
Mar 11, 2008 at 3:56 PM
Avatar
JUSTME3040
  • MEMBER
  • 3 POSTS
The fact that the car warms up in the driveway normally, but cools down when it is moving leads me to believe this is a problem with the thermostat and not the coolant temperature sensor. If my thermostat is stuck open, then that would explain why the car warms up when it is sitting still, but when it is moving it cools back down (the cold air is moving over the radiator). This would also explain why on warm days the effect is much less pronounced. Does this sound plausible? Just want to make sure I'm not on a fool's errand here.
Mar 12, 2008 at 9:20 AM
Avatar
RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
The thermostat controls the engine temperature-the CTS senses it and reports to the computer the actual temperature of the engine.

Plausible-Yes
Mar 12, 2008 at 9:59 AM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.