93 Civic, 1.5 SOHC. Wife had the water pump replaced while I was in the desert. Ran fine for awhile after I got back. Started running hot on the interstate one day and I noticed that the water was low but did not see any leaks. Changed thermostat, topped off coolant and while I was checking it out in the driveway, noticed that the fan was coming on a little later than it used to judging from the temp gauge. Changed radiator fan switch (at least I think I did. I changed the sensor/switch that is mounted on the thermostat housing). Ran hot again. This time, I could see where the radiator was leaking from a cracked top tank. R&R radiator. Ran fine about 2 weeks. Sitting at a stop light after running for awhile, the temp got up almost to hot. Limped a mile to the house and noticed that the cooling fan was not running. Changed fan relay and coolant temp sensor. Has only crept up very slightly from normal a couple of time since then. The problem now is that the coolant gets pumped over to the overflow bottle, but never gets sucked back into the radiator. Also, the radiator still has pressure on it after sitting for 15 hours or more. I have put 2 new radiator caps on it and the problem remains. I hope that this is a simple problem and I am just an idiot as evidenced by all of the "good" parts that I have replaced.
I read in one post about bleeding the air from the system. I don't recall seeing this in my Haynes manual but if that could be the problem, I could use some guidance here. Also, someone mentioned a temp related sensor/switch located near the oil filter. Does this apply to my car?


Modified by sloride at 10:08 PM 7/3/2003

 

Really could use some experienced insight into this problem

 

Bleeding the system is a MAJOR priority when replacing any cooling system part.
e-mail me if you actually want the whole process. You can probably search the internet or honda-tech to find the procedure.
A unbled cooling system in any car spells D-I-S-A-S-T-E-R. You have the symptoms but since it is a necessity to bleed the system, you might as well do it.

 

restriction some where in the cooling system

 

just try one morning (when car is cold):

-Make sure the overflow tank is on the Max position.
-Take the rad cap off.
-Turn on the car and let it warm up
-Wait till the fans start to work at least twice then go and open quickly the bleed valve on the thermostat housing, open it a couple off times and wait till it squirts coolant out, but just a bit.
-Put the cap back and on go out for a ride to see if it worked.

BTW, just out of curiosity, are you sure you're using the proper coolant/water mixture? Honda Coolant?

if you did all of this, i would say the pump is faulty.

 

I will have to drive the car for awhile to insure that it is fixed but there WAS a lot of air in the cooling system. I've changed radiators in other cars before and never had to go through any extra bleeding procedures. With this Honda, it sure seems that you do.
Thanks to all who replied. Great forum.