Rep Power: 0

I purchased a 93 Civic Ex 4 months ago. When I purchased it they put a new head and water pump and timing belt on it. I also put a new radiator in it and new thermostat and replaced the cooling fan and the fan relay. The promblem I am having is sometimes the temp will almost get to the red and then itwill cool back down. It only does it when it at idle and it does not do it every day it might go two or three day's sometimes even a week in between before it does it again. I took it to the Hoda dealer and they replaced the thermo switch in the thermostat housins and put in a new thermostat and said it was fine. I let the car run for a hour one day with the air on and it never run hot and the fan work fine. The only other thing i know to do is hook the fan up were it runs all the time when the car is running but I really dont wont to do that. I would appreciate any help I could get with this matter.

Thanks

 
Rep Power: 0

First off it sounds like an obstruction in the thermostat almost like the stat is hanging shut forcing the temp spike before it opens. Second you can put an override switch on the electric fan and switch it elmanuel style when you notice its getting hot. Also its not real good to get any alum head engine hot so be careful maybe even put a real temp guage on it so you can see just how hot red is! Good luck!

 
Rep Power: 0

I replaced the thermostat twice.

 
Rep Power: 302

Make sure you bleed all the air out of the system. There should be a bleeder screw right at the top where the thermostat is. Put the heater on high, and open the bleeder just a little. If airbubbles come out, keep adding coolant to the radiator until only a steady stream of coolant comes out of the bleeder. The bleeder is there for a reason, but most people overlook it.