intekragsr

This is really strange. My temp needle rises slowly past half way mark everytime I come to a stop even though I have a manual fan switch. It will only go down if I blast my heater.

WTH could be causing this? I changed out my thermostat and though that would fix it.

TurboR1391

Could be air in your coolant or a blown headgasket.

intekragsr

hmm...

Its not a blown headgasket because when I rev my engine with my radiator cap off, the coolant doesnt shoot out.

I really dont think its air in the coolant because I left my car idle for like 20 minutes with the cap off and the bubbles ceased to exist.

Im confused.........

RyanAutry

You know, this same thing happened to me with my old Datsun. I had a lot of corrosion inside the Radiator and engine. I got the engine and radiator flushed and it worked great...

Just a thought.

intekragsr

how do you flush the motor? Flushing the coolant is going to suck Have to take off the turbo to get to the drain bolt on the block.

Any other ideas or solutions?

drift

sounds like your thermostat is stuck closed.

the heater core is circulating from movement caused by the water pump and is providing for cooling, whereas the rest of the system is backed up by the thermostat.

g2turbo

my car did the same thing. But only in very humid hot weather. The cooling system wasnt efficient enough and the one stock fan couldnt pull enough heat out. I finally broke down and bought a full size fluidyne. You'd be suprised at how well these work. Then i mounted two slimline fans on the front. My fans hardly even have to turn on and when they do its for a few seconds.
but check all your systems before getting a new radiator. CHRIS


[Modified by g2turbo, 1:07 PM 11/30/2002]

Wes V

Back flushing the engine isn't all that hard and you don't have to remove the block drain plug! Disconnect the radiator hoses from the radiator and then rotate the upper radiator hose so it points upward. Remove the thermostat. Then just run a hose into the upper radiator hose. This is the opposite directiion of normal water flow through the engine.

As for your problem, I have a similar problem that occurs when the water lever gets low (of course, I still don't understand why it gets low in the first place). Here are a couple comments and ideas that may help.

The water pump on Hondas sits fairly high in relationship to the radiator and I wonder if it tends to go dry when at low RPM. This gets back to prior comments on "air in the system".

At low RPM, maybe the volume of the (old) water pump just isn't up to job.

Is it possible that your thermostat (ya, I know that you replaced it) is sticking? While doing that back-flushing, I'd recommend buying a factory replacement.

When the engine indicates that it's hot, is the upper radiator hose also very hot. If not, then it's not circulating water.

Have you done anything that may cause the water to go through the radiator too fast? Some people think that removing the thermostat will help, but it can hurt!! The reason is that the water has to stay in the radiator long enough to transfer the heat from the water to the metal of the radiator. This is why you may see "restrictors" sold for replacing the thermostat.

One last thought, you could pull out the radiator and have a shop "rod-it-out". What they do is remove one of the caps and run a rod through the cores. The cost shouldn't be that much if you bring the radiator to them.

Wes.

BoostedH23a1

ya he is right... check: thermostat, water pump, headgasket, hoses, also make sure u have close to 50:50 mixture antifreeze and water. water boils faster when there is no antifreeze.. just like tap water vs. salt water.

earl

Stock Honda radiators cannot be cored out because of the plastic top. Assuming you don't have a blown head gasket, you are full of coolant, the thermostat is working properly, the impellers on your water pump are not rusted away and your fans are coming on in a timely manner, it's time for a new radiator.