1998 Honda Civic Overheating when running A/C or cool outsi

In reply to:

Does the radiator fan comes on when the A/C is turned ON?

When engine is cold, is the coolant level in radiator correct?

That's something I have to confirm but I'm pretty sure both fans operate when I turn on the A/C - matter of fact, the radiator fan is new.

The coolant level in the radiator is correct. I bled the system and ensured it was filled to capacity.

I checked it out over the weekend. Both cooling fans are coming on and the blades are rotating in the proper direction.

As far as I can tell, there's no blockage at the radiator or condenser fins, but to be able to get a better look, perhaps I should take them out?

Coolant does go to the recovery tank, however, in order to see what happens, I put in my no spill funnel again and ran the a/c with the temp. Selection switch in blue (cool), and then ran outside air with my temp. Selection switch in blue (cool). At both times, after some running, the coolant began to boil wildly from the funnel, and the level was rising within the funnel, whereas if I had the temp. Selection switch in red (hot) and had the a/c off, the bubbling wouldn't be as wild and the level wouldn't rise. It's like I was pulling a vacuum on the fluid making it rise, but I wasn't.

I have to feel the air again because it was hot underhood as expected, although the air from the fans wasn't as hot as the engine compartment - but we had some hot days out where I live so I have to wait until it cools down in order to feel the incoming air.

The lower hose is way cooler than the upper hose. The upper hose is hot to the touch whereas the lower hose, I could relax my hand on all day.

I have to purchase a reader.

Thank you very much!

Ok will do - quick question -

I've changed the thermostat about 3-4 times now. The first 2 times I got a thermostat that was higher temperature, then I learned to go with the OEM spec thermostat. Is this a case where I may have to get my thermostat from the dealer rather than my local autoparts store because they don't seem to work? Thanks!

Try running the engine without the thermostatic valve. Be sure to install the rubber surrounding the valve which serves as your gasket. If the overheating stops, check for the coolant pressure in the system. If pressure is good, check for restriction. If pressure is low, check the water pump.

I ran the system with the thermostat removed. There was no overheating and when I finished driving, the lower radiator hose was a lot hotter than usual (usually it's warm enough to grab). I'm leaning towards there being a restriction somewhere in the cooling system. I was going to buy all new hoses for my cooling system, and do a flush and refill. Does this seem like the proper course of action? What do you think about the flush/cleaners that you mix in before doing the flush or would you recommend flushing the system out just with water? Thanks!

Most probably you have a water pump problem.your thermostat was changed several times, however the pressure of the pump in not enough to open the thermostat fully. when whas the last time it was changed? before you replace more parts,have it checked,replace if the blades are badly corroded.

Before you spend more, have the water pump tested/checked.

I changed the water pump in the middle of june of this year. Before that, the water pump that was in the car was the original water pump and finally died. The problem existed though before that water pump died. When I replaced the water pump, I also replaced the timing belt, tensioner, and pulley belts. I replaced the original water pump with a gmb water pump and a contitech timing belt. Thanks!

Hello all: I finally got aroudn to changing out all my cooling system hoses and doing a complete flush and refill on the system, as well as install a new thermostat to factory spec (unfortunately I wasn't able to get an oem thermostat but I didn't skimp on the costs and got the best one possible that had the oem specs). When I removed the water bypass hose, I found the cause of my problem. The passage to the thermostat housing was blocked. The old hose was also blocked up the midpoint of the hose where it bended. I had to drill the blockage out and clean out the chamber on the thermostat hosuing and when I looked in the hose, it appeared to be putty. Now, I never used radiator stop leak nor put anything detrimental into my cooling system however, I did have a fallout with a tech. In the past who could've done it, although I'm not blaming him for it. It was a funny thing to see though and I didn't get furious over it - if anything, I got kind of mad at myself because when I was squeezing the hoses to check for blockages, I squeezed this hose countless times and never felt any resistance but when I took it off, the material inside was solid. Nevertheless, that was the cause. I put on new silicone hoses with the original stock spring clamps (any opinions with this setup). So far so good - I'll try the ac and outside air later but I'm betting that this was the cause. Thank you very much for all your help and have a good day!