Questions and Answers

Sluggish Toyota Previa Q. Hello Vincent, I would love your advice on a problem I have been experiencing with my van for almost a year. We have a 1995 Toyota Previa LE/SC with approximately 98,000 miles. When the motor is warm, it runs great. However, during cold weather the motor is extremely sluggish and has little to no power just before the thermometer reaches "operating temperature" on my dash.

It runs fine just until that point and then again once I pass that point. The dealership and an independent mechanic said the cylinder walls have developed a "ring" that is retarding the timing. I have had the knock sensor replaced. This solved the problem for about two days.

I have had all systems checked and everything seems to be normal. Compression, okay, fuel and oil consumption, okay. The exhaust is not too dark or light. There are no electrical shorts. Both the dealership and independent mechanic claim to have checked everything that could cause this.

I was quoted approximately $3,000.00 to repair this. Do you have any suggestions? Again, I would appreciate your advice.

Thanks,
Dave

A. Since this is temperature related and it happens under the same circumstances it should be fairly easy to track down. Now my first instinct would be to suspect the Engine Coolant Temperature (ECT) sensor. A bad ECT would cause the same symptoms you describe.

As far as the possibility of the timing being retarded, I would suspect a bad Crankshaft Position Sensor before a "ring" around the cylinder walls.