Was high reving first gear on a main road then stopped at some lights, took off a again and noticed my water temp was slightly above mid way point, so i ran my heater on level 1 and it immedietely went down to normal operating temperature.

Then when coming home i decided to just sit in the middle of the road and there we go, the temp begins to rise again, start driving and the temp goes back down to normal level.

Got home and let the car idle in my drive way and yep it begins to rise again but stays at 3/4 and just seems happy to sit there. Pop the hood and the radiator fan is working it's **** off (sounds louder than usual), then the fan turns off (temp still at 3/4) and it immeditely drops to normal operating temperature.

Is it possible the fan isnt working hard enough? What else could the problem be? This happened a few months ago (both on really hot days) and i burrped the system but there wasnt much air in there at all. The car also has no problems reaching normal operating temp on cold start.

Thanks

92 civic with GSR motor I/H/E. Not running aircon.

 

Bad thermostat?

Kev

 

Bad T-stat and you may have a bubble in your cooling system as well.

 

i would try bleed air out of the system. I had the same problem with an overheat and it was so bad smoke would come out the coolant reservoir! Fill the radiator to the complete max.. and make sure its to the max. all i had to do was let it idle for 30 mins with the heater on, but fan off.. radiator and reservoir cap off. works 100% everytime
i would check this before replacing the T stat.

 

If it was a bad T stat, wouldnt it have problems heating up on cold starts? I only replaced the t stat about 40 000 km ago, genuine honda too!

 

Will do, thanks! My radiator and over flow tank are both max with coolant already. When you say fan off, do you mean heater fan or radiator fan?

 

well i bled the system with the heater on full blast until in the middle, but the radiator fan didnt come on. It didnt bubble at all, the coolant just stayed level with the top of the neck and stayed there. See how it goes from here on in!

 

your supposed to bleed the system with the heat turned to full red, but without the blower motor on, this makes it so the heater core is open as it can trap air. also make sure the car is on a level surface.

any smoke? check your oil for water or coolant, itll look like chocolate milk if this is the case, headgasket

 

i did put the heater on full red but i also had the blower motor on, damn guess i will no for next time...No smoke and oil looks fine!

 

Sometimes it takes awhile for the fan to kick on.

Try it again, if you can have the front raised a little that helps.

Put heater to hot setting, leave fan off.

Let it run for about 25 mins, fan should come on at least one time, two times is ideal.

 

when was the last time the water pump was replaced?

 

same time as the tstat, so 40000 km ago.

 

Does the fan actually work?

 

its spins, if that is what you mean't, as to its effiecency im not sure. Is it suppose to PUSH or PULL ?

 

Missed that and it was right int he first post. Possibly the rad is clogged/needing replaced?

 

i had that same issue in my gsr it was a blown headgasket

 

i hope its just air in the system. i know have nerve wrecking it could be cause your always worrying if its a bad head gasket.

 

Yea pretty much. Im not blowing any smoke nor is my oil milky. It has been alright since i gave it a quick bleed so see how it goes.

By the way, if i wanted to do a flush, i need to let coolant out of the block aswell through that big bolt in front of the block? Any idea how much coolant is left inside the block?

Thanks

 

TO let you know, you don't have to have milky oil or blow smoke to have a blown headgasket.

 

i drain my coolant with the pin thats under the radiator. disconnected the lower radiator house(one that goes near/into themostat) sprayed water into the hose so it would cycle through the block and come through the upper radiator hose back into the radiator and exit out the radiator pin on the bottom. Coolant is mostly water so im pretty sure it wont hurt anything. This might be a problem if you have a bad head gasket. and there will be a decent amount of coolant still left in the block & hoses so have paper towels on hand.
Also a tip is to not let a big amount of coolant to puddle on the drive way and make sure not to dump the coolant responsibly. Pets will be attracted the the sweetness and it can potentially harm them.

 

If you notice the overflow tank filling up on longer drives, it's most likely your headgasket. My CRX is doing this right now

Also feel the lower radiator hose, if the thermostat is stuck closed causing you to overheat the bottom hose should generally be cold, even when temp gauge says it's warmed up.

 

It was a blocked radiator!

 

How did you find out it was a blocked rad?

 

Noticed the radiator hosed had collapsed. Took it to a radiator place who did a flow test which it failed. Replaced and problem fixed!