heater issue

[B18B-SC]

well ive been in phoenix for the last 3 years, so i never really had to use it. i just recently moved back to colorado, and now have to use the heater. well it blows nice and hot when im driving. but when i come to a stop it cools down a lot. as soon as i start moving again it gets really hot, like it should.

its not a huge deal yet, because its not too cold yet. but in the dead of the winter this will start to piss me off.

anyone have any idea what it could be? the only changes ive made in the heating department, would be replacing my full size radiator with a half sized fluidyne. i also replaced both of the fans with slim fans one 12" and one 14"
would this have anything to do with anything?


this is all in a 2001 integra

[Martian]

How long has it been since you've put a new water pump in? With the other mods you've mentioned I would expect your temps to stay fairly low and regulated. But if the pump is going out, it won't be able to push the water through the block quick enough to disapate the increased heat that you have with higher rpms and the varying loads.

[B18B-SC]

still on the original water pump. but i only have 94k miles, its a 2001. i will be changing the timing belt soon. so i will change the water pump when i do that.

[B18B-SC]

i think its now the water pump. my motor is making some awful noise right now. almost sounds like a rod knock. but it is not rpm consistant. and it sounds like its coming from the timing belt area almost sounds like its on the back side too, right near the water pump. so im praying its just the pump. i really dont wanna buy a new motor right now.

i just tested the compresson all 4 cylinders were at 140 across the board, that seems about right to me for the elevation we are at.

[nicklk]

I have had the same issue with every integra I have driven....

My 94 did it with a brand new water pump, and my 91 does it now...and its got some miles on the water pump....I havent really found a resolution to it tho:(

[boostedEG]

well you get your heat because a fan pulls/blows air over the heater core, which is filled with hot water/coolant. so if your getting heat while driving but not when sitting still then you are gettin flow through the heater core at higher RPMS but not at idle. there is only 2 things i could think of that would cause this...


a water pump thats moving considerably less volume than it should be (almost no volume at idle) causing the water in the heater core to quickly cool... this is fairly unlikely, and the car would most likely overheat.

or the more likely cause... a partially plugged heater core that is not allowing much volume through it. pull the two heater core hoses off at the motor, not the firewall, and put a garden hose to one hose (either one) and just check how much water flows out the other one. then put water through the other hose to flow in the opposite direction. it is possible that the hose will unplug whatever is in there, but if that doesnt work you will need to replace the heater core.

an air pocket in the heater core might be able to cause your problem too, but i kinda doubt it.

if your dont feel like doing any of this work yourself PM me, i will do it for cheap.

[B18B-SC]

well, i am replacing my water pump, oil pump and timing belt tommorrow. so i will see if that cures the problem. the heater is not my huge concern right now, just because i have some funky noises coming from my engine right now. which im hoping is the water pump. but thanks for the offer.

[boostedEG]

also check that the heater core flow valve is operating properly.

[QuarterMile]

I can replace your heater core if u need me too.
I can do it in a reasonable time and for cheap .Let me know