lawman2391

I have a 1998 Civic EX with a little over 200,000 miles on it. I live in Minnesota and the past 6-8 months I have been having various problems with temps in my Civic.

This past summer I was overheating and so I checked and replaced all fuses, replaced relay switch, checked cooling fan motor, replaced thermostat sensor switch, and replaced the thermostat itself (with a fail safe one that stays open all the time if it fails). None of that worked and so (stupidly) I checked the coolant level and it was very low. Once I did this the temp did not run hot anymore...chalk it up to experience and doing the easy thing first, right?

Anyway, being that I am in Minnesota and it has turned cold now I am experiencing a different issue. First of all, when driving, my temp gauge never rises above "C" on the gauge and the heater blows mildly warm, but not hot (as it used to - it used to be like a dragon in the dash). When at idle for a time (5-10 min or more), the temp will rise and it will blow warmer air. If I leave the heater off and let the temp rise, it will go above normal and get close to "H" on the gauge. Turning on the heater full blast, brings this down to normal range quickly. After extended idle and getting back to road driving, the temp drops back down to below "C" and heater is back to mildly warm again.

I have checked the coolant level once again and it is fine (not low). I have not checked anything else at this point and figured I would field suggestions from the forum as to where to start on this, as to not repeat my inefficient efforts this last summer. I have received a couple of suggestions from friends/neighbors on this, but figured this is a better place to get advice before diving in...THANKS!