My '92 Paseo....

[Fuel]

it has always done this, ever since i got it with 83k miles, now 133k.

at cold start up, it does not heat up very quickly. (it probably doesn’t have a thermostat.) in very cold weather sometimes it doesn’t heat up at all.

in normal weather at cold start, it usually takes about 4 minutes of driving to heat up. during this time, it does not shift into overdrive/4th gear (auto). it will drive at really high RPM’s before a certain point on the heat guage, then it shifts. i can remember one day driving in about 30 degree weather and driving on an interstate at about 70 mph in 3rd gear at like 5.5k RPMs, the thing would not shift no matter how fast/long i drove!!!

also, when i floor it before this point it will not go to redline. the car only has about 75% of it’s power before heat-up.

what’s going on? is this it’s way of protecting itself? is it programmed to do this, or is this an phenomenon of some sort. does every car who doesn’t have a thermostat do this? the car is in good condition.

[MadScientistMatt]

It should use a thermostat. They’ve been used on virtually all water cooled cars since the '30s. However, it sounds like the thermostat may be defective, letting some of the coolant seep by and keeping it from warming up quickly. I would replace the thermostat. The other effects could very well be some sort of computer setting to protect the engine from being driven hard before it’s warmed up.

[Chris_Luongo]

I’ve never thought about the overdrive gear being locked out during cold operation, but it has made me think of something. On most automatic cars, there’s a special compartment in the radiator that the transmission fluid pumps through…this basically serves to cool the transmission fluid during high-temperature operation. But, like anything else, you don’t want stuff to be TOO cold.

Like MadScientistMatt says, your car surely uses a thermostat. It most likely has failed and stuck open. Or, a previous owner may have removed the thermostat for some reason, but that would cause all manner of problems. Since thermostats are so dirt cheap, I wouldn’t even bother trying to diagnose the problem—just go ahead and replace the thermostat.

Thermostats are rated for certain temperatures—195F is a common one. When cold, the thermostat locks shut, meaning that engine coolant (antifreeze) isn’t allowed to be pumped around. When 195 is reached, the thermostat opens, and coolant starts flowing. When your thermostat is stuck open, the coolant is flowing around all the time----which is why the car takes forever to warm up.

And on cold mornings, your hot coolant, flowing through the radiator, is actually going to serve to WARM your transmission fluid----this will likely cause your transmission to shift into overdrive sooner, and lead a healthier life overall.

So you have four incentives to fix this easy problem. 1. Longer engine life. 2. Longer transmission life. 3. Better performance at the beginning of your trip 4. Heat for your body on cold mornings.

If you’re handy with tools, the thermostat is easily accessed on most Japanese cars. The thermostat and gasket are usually sold separately; don’t forget to buy both. Figure on spending $10 or less. While you’re at the auto parts store, spend another $15 on one of those Haynes or Chilton manuals for your car----they’re a little skimply but they’ll certainly include instructions on changing the thermostat.

And if you’ve never changed the coolant, you probably should. So you might as well buy a gallon or two of antifreeze while you’re there, and take care of the whole thing at one time----you’re likely to spill some of the old coolant while changing the thermostat anyway.

[racer72]

I am going to guess the car has a thermostat installed, but not the right temperature setting. Your car should have a 192 degree thermostat installed. If your car did not have a thermostat installed it would overheat, not run too cool. The thermostat is designed to regulate the coolant flow through your radiator. If there was no thermostat, the cooland would pass through the radiator too fast to cool. As suggest previously, check and/or change your thermstat as required. Something I have to do with my 66 GTO when I drive it in cold weather so it will warm up is block of part of the radiator with a piece of cardboard. Never cover more than half and keep an eye on the temperature gauge so you can adjust the air flow through the radiator of optimal operating temperature.

[Tuckerfan]

It’s possible that someone removed the car’s thermostat due to the engine overheating in the summer. The shifting problem sounds more serious, however. If you haven’t had the transmission fluid and filter changed, I suggest you do so immediately. If you’re lucky, you just have dirty fluid that’s causing the problem, if you’re not lucky, you’re going to need to have the transmission replaced.

The power loss problem is caused by the engine not warming up. The carburator (or fuel injection system) is designed to run the car with a rich fuel mixture until the engine heats up. So if your car doesn’t have a thermostat (or if you’re low on coolant), the car is going to run on a richer fuel mixture (with not enough air to support full combustion) until the carb or fuel injection system detects that the engine’s warm enough to run on a leaner mixture.