Recently bought this car and fixed a bunch of electrical issues, with help from this forum. Thought I would give this a try for a new issue.

The upper radiator hose was leaking and I noticed the radiator was pretty clogged up in the front. I replaced the upper hose, radiator and threw a thermostat/radiator cap in at the same time.

Thermostat will not open, took it back out and boiled it and it opened right up. Also the upper hose is hot, lower hose is cold when car is warmed up to operating temperature. The fan never kicks on unless I turn the A/c on and both fans will kick on.

The car doesn't get hot but I am still concerned with no fan or the thermostat not opening. I took the cap off and looked down the neck of the radiator, with the car running. It doesn't look like there is any flow of the coolant.

I took the thermostat out and ran the car without it. In the radiator neck it looked like there was a little flow but there were a bunch of bubbles.

I then did a compression test. Cylinder 4-180 psi, 3-170 psi, 2 150 psi and 1 180 psi.

I am leaning toward the water pump not working???

 

That would be my next guess. Is the car overheating?

 

The car does not overheat it will get about half way up the gauge and just stay there.

 

Going halfway up the gauge then staying there sounds to me like the thermostat IS opening.

Don't know where you live, but around here it's cold enough so I don't expect the fan to run anyway.

Have you bled all the air out of the cooling system? Hondas don't like to have any air in there.

 

I agree with Jim about the thermostat opening. If the coolant was circulating though the system, the lower hose should not be cool. That is why I agreed that the water pump may be the culprit.

If your timing belt is due for a change, I would change out the water pump.

 

I bet water pump and thermostat are fine. If car doesn't overheat and temp comes up to middle range (w/ thermostat) in place, the water pump and thermostat are likely working correctly.

Only evidence to suggest water pump might not be working is you can't see water movement through radiator cap and lower hose is cool. It's supposed to be warm, perhaps < 120F depending on coolant temp.

The cooling fans not engaging is not evidence of no water pump circulation. This happens w/ cold start engine and cool air temps. Cooling system will circulate enough by convection to maintain acceptable temps for quite some time at idle. If you drive, the fans will eventually engage. I've noticed this on both my older hondas; 90 and 94 Accords.

Before replacing a good water pump, I would pinch off the upper radiaotor hose (to simulate zero coolant flow) and see if it begins to overheat (don't let overheating occur).

good luck

 

I live in Oregon so it is has been in the 40's.

One of the times that I was checking things, the thermostat was out and I was running the car and it was warm, I had the radiator cap off. I opened the bleeder valve and coolant looked like it was pumping out of the radiator, until I tightened the bleeder back up. I made me think that the water pump was working. But I am not sure.

 

With temps in the 40s, I'd expect it to be difficult to get the fans to run, since the radiator is new (you said..). Even in summer, I sometimes have to cover up the grille to allow it to get hot enough.

 

So should I just drive it and keep an eye on the temp.? I just seems weird that water pump would go out without any leakage.

 

I've heard of the impeller blades corroding down to nothing, but it's kinda unusual. If that happens, the temperature should climb high when you're driving.

1 - Make sure there's no air pockets in the cooling system. Use the bleed screw at the T-stat and check the actual radiator (not just the overflow tank). That way you can have more trust in your dashboard temperature gauge.

2 - Watch the gauge to make sure it's not going much over 1/2-scale.