ongiong overheating

cattywompus · Post by **cattywompus** » February 2nd, 2005, 1:52 pm

I have the same overheating probs on my 93 DOHC MX-3 I've read so much about- after 20 mins of driving the temp shoots up. I replaced the water pump, thermostat, and flushed radiator. Fan works. But what helped the most was replacing the radiator cap. Now it runs much better but the temp still starts to climb after running 20-30 mins. I turn the heater on for a minute and temp drops and I'm good for another 15-20 mins. Any suggestions?

Flashpoint2 · Post by **Flashpoint2** » February 2nd, 2005, 3:07 pm

Only thing I can think of is the Thermostat. I know you replaced it, but I had the same issue, and it was fixed with one of those "fail-safe" thermos from crappy tire.. cost like 13 bucks.

Typhoonk · Post by **Typhoonk** » February 2nd, 2005, 3:18 pm

how bought the temperature sensor that triggers the fan?

Tunes67 · Post by **Tunes67** » February 2nd, 2005, 4:42 pm

Have you checked with a mechanical water temp gauge? Sometimes the electronic sensors & gauges can give false readings.. also.. if you or a previous owner ever used any kind of Stop Leak in the cooling system.. this stuff will hose sensors bad. Another thing that could cause this might be a air bubble trapped in the system.. preventing proper flow of water.. This might sound weird.. but park your car on a hill (front end uphill).. take off the radiator cap.. start it up and watch for air bubbles.. also.. grab a meat thermometer and keep track of the temperature of your coolant in the radiator.. this will also help you determine if your thermostat is opening at the proper temp.. (temp will stay cool and then jump rapidly when the thermostat opens) Just a couple of things to check..

Tunes67

cattywompus · Post by **cattywompus** » February 2nd, 2005, 5:00 pm

i'm going to replace the thermostat this weekend with a dealer part, but the hose is hot indicating the thermostat is opening?????? The fan turns on and off. I don't know where the sensor is for the fan or the water temp, but if I did I would replace them both. Also I just noticed after driving for 15 minutes that my new radiator cap is leaking. Is a 13 lb cap right or is something causing the caps to go bad?

Yoda · Post by **Yoda** » February 2nd, 2005, 10:38 pm

I have seen the so called name brand parts bought from some the big retail automotive chains be not any better that the original defective thermostat. Using a factory original parts solved the problem.

Flashpoint2 wrote:Only thing I can think of is the Thermostat. I know you replaced it, but I had the same issue, and it was fixed with one of those "fail-safe" thermos from crappy tire.. cost like 13 bucks.

93_4Banger · Post by **93_4Banger** » February 2nd, 2005, 11:29 pm

the same thing happened to me and it was because of rotten portions of my radiator right close to the end tanks so i got a new rad and it works perfect now.