I own a 96 accord ex coupe. Just recently had the water pump fall apart; replaced water pump and timing belts while i was at it. Then just last weekend, car starts running hot. I get it home and see that i have a pinhole leak in a heater hose. This was spewing antifreeze into the radiator fan which was splashing antifreeze around the engine bay. I had the hose replaced and refilled my antifreeze. Now the car runs good except for one thing. The engine temp guage on the dash cluster goes from cold to about mid-level quicker than usual. It will feather just above the mid-level line but doesnt run hot. Car used to take a good while to even get to about a quarter of the way on the guage. AND when i turn the car off, the radiator fan runs for a long long time. Alot longer than it used to. I just got home from work, about a 15 minute drive. When i turned off the car, i started a stopwatch. The radiator fan ran for over 15 minutes before it shut off. Something just doesnt seem right with this. I checked when the car was cooled down and my antifreeze level looks fine. Any help or ideas? Thanks in advance.

 

im having this same problem so i just bypassed my rad fan to stay on

 

Anyone else have any ideas on this?

 

How about the thermostat? Anyone think this could be a contributing factor? Are they relatively easy to replace on the F22B1?

 

1. What coolant mix ratio did you use (e.g., 50/50)?

2. I would recommend first to see if there is still some air that needs to be purged from the system. Open radiator cap, turn heat to high, warm up the car, rev the car as this may get any remaining air purged out, feel the bottom radiator hose to see if it is hot (if it is hot, the thermostat opened), then gentle squeeze the upper radiator hose to get any air out. Top off with coolant along the way/

3. The thermostat is not hard to replace; but, if it's been on there awhile, be careful when removing the bolts (might have to do a little gentle loosen/tighten sequence to help it come out without the bolt snapping).

If you did not have overheating problems prior to this, I wouldn't think it's your thermostat though. But coincidences do happen.

Good luck, I have to take off for now.

 

Thanks for the input. One more thing that I am worried about: the engine coolant temperature (ECT) sensor. Could this be a factor? It worries me because the hole in the heater hose spewed antifreeze and this sensor is placed almost directly in front of where the hole happened to be, so i'm pretty sure that the sensor wires/connector were probably sprayed. Wondering if this might be it.

 

I am willing to bet there is air in the system as well. Follow #2 and make sure all air is out of the system and top of with fluid.

The ECT sensor would not make the car overheat, it simply feeds readings to the ECU for fuel/ignition adjustments. If it was broken you would get a CEL.
There is a 1-wire coolant sensor that controls the gauge on your dash, if its broken then it could be giving a false reading, but not likely.

 

Thanks, that really makes me feel a bit easier, as I'm sure the ECT would not be cheap. I will try #2 to see about removing any air that is in the lines and let you know. I may not be able to get to it right away though. Do you forsee any problems or damage if i have to run the car a few more days before purging the air? I won't be driving more than 15 minutes at any time length of time.

 

probably not but if you needle is going past half way on the gauge that means the car is running hot and is still bad for the engine. just cause the needle isnt on H doesnt mean the car isnt overheating. it takes about 15-20 to bleed the system just run the car with no radiator cap until the fan cycles twice, top off as needed

 

well i went home after work yesterday and did just like you said, along with my neighbor who used to work at an autoparts store. Ran the car for 20 minutes with the cap off and the heater at full blast. I DID notice some bubbling as the car ran, which i figured was air being purged from the lines. I then topped off with coolant, as well as put some in the reserve resevoir and then drove the care up the street and back for a few minutes. Didnt seem to have much change on the temp needle: still about the midway point. But then this morning on the way to the gym, just a couple minutes before i got there, the needle was higher up than usual. So I'm wondering if i need to try doing the purge again, or if there is something else that could be wrong.

While purging, the upper radiator hose was hot, but the lower radiator hose was cool. That means the thermostat was open, correct?

 

That meant the thermostat was still closed. Once the thermostat opens, coolant can flow through the lower radiator hose and purge out any air.

Did you rev the car while trying to purge the air? Do this to help.

 

I'm beginning to think the thermostat is stuck closed and isnt opening for some reason. I'm thinking that the thermostat has never been replaced, and is about as old as the water pump i just had replaced. Could the thermostat have been affected by the car running hot for a short time when the water pump went out?

 

The thermostat has a bi-metallic spring that varies the opening of the valve in the thermostat according to temperature. Think about how many times that cycles. It can "wear" out. Replace it. Same for the radiator cap.

 

if the lower hose isnt getting equally as hot as the top then you should replace the thermostat

 

right. the lower hose is definitely not getting as hot as the upper hose. Does ALL the coolant need to be drained in order to change out the thermostat? My Haynes manual says to, but I'm wondering how much will spill out when i loosen the hose off.

Also, on the way to work this morning, i tried running the heater full blast while driving and it seemed to keep my temperature needle below the midway point. Do you think the car will be ok driving like this until i can change the thermostat out this weekend?

 

That's ok as long as the engine doesn't have to work too hard (high speed driving, trailer pulling...). Your heater is in fact a small radiator and coolant will flow through it even with the themostat closed. Years ago running the heater was a method to prevent overheating: in those days we did not have electric fans to drive air through the radiator...
Also you may want to open some window to improve cooling.

 

It sounds like a thermostat problem to me. I have a 94 EX, and within the past year, I've had to replace the thermostat, water pump, and radiator...so coincidences do happen. The thermostat is by far the easiest of the three to replace. However, if it is still the original thermostat (like mine was) some of the bolts holding the thermostat housing in place might be stuck on there pretty good.

I didn't drain any of the coolant when I changed mine...I just made sure to have a little tub under the car to catch anything that did come out (not too much), and as soon as you disconnect the hose just bend it upwards so nothing else comes out. Then once you get everything back together, bleed out the air and top off as needed.

 

Ok, today i replaced my thermostat and radiator cap. Bled the air from the system and then ran the car moderately hard for about 5 minutes. Temperature gauge needle stayed more consistent with the way it usually looks, somewhere between a quarter and halfway. Very pleased; i think that should have done the trick. Still have a problem though. Radiator fan is still running for a long time after engine shut off. I timed it last Monday and then again today after the service work. Both times, the radiator fan ran for about 15min 20 sec. I can't figure it out. A few "car guys" i know said the same thing. I'm worried about my battery draining now. I looked on tasauto and i see a Radiator Fan timer that says it limits the amount of time the fan will run. But my Haynes manual doesnt have any info on it. Could this be my problem? Anyone have an idea on this?

 

If the fan runs up to 15 minutes after you shut it off, the radiator fan timer is working correctly. Usually this will not drain your battery.

If it ran way longer, then yes, the fan timer may be bad and this can drain the battery.

When I used to have a 5th gen Accord, at around 200,000 miles, the fan use to run after I shut off the car more frequently than before. Later when the radiator cracked at the top (the OEM radiator is plastic and metal), I had the radiator replaced. After that, the fan didn't come on as frequently after I shut off the car. I felt maybe the coolant wasn't flowing as efficiently in the radiator due to age and possible blockage.

 

Ok, so it's been two weeks since I changed the thermostat and my car is running great again, engine temp is back where it should be. But I am still having the problem with the radiator fan running for long periods of time. And I'm beginning to see my almost brand new battery struggling to crank the car in the mornings. If the car has been sitting all day, I can turn the car on for two seconds, turn it back off, and the radiator fan immediately kicks on and runs for a while. This can't be normal. My neighbor believes there may be an engine temperature sensor or something that is bad and the ECU is in a "safe loop mode" or something to that extent. Any ideas?

Thanks!

 

I was thinking that if it would be a bad engine temperature sensor, that I would get a Check Engine Light, but I'm not getting one...