Overheating! Water Pump?

[Chicagos13]

Have had my swap for almost three years and have never had this problem. My intuition is the water pump, but here's the story. When driving the car normal/hard the car does fine. Temps get no higher than the third hash mark on the temp gauge (factory). However, when you stop the car and let it idle for more than I'd say a minute or two, you can watch the temp begin to rise up to around the fifth hash mark. I do have an SR radiator and my mods are limited to your basic bolt ons. What do you guys think?

[Silvia007]

probably thermostat.

[JJ240]

Check for low coolant, and see if there is any coolant residue under the water pump. Usually water pumps have a drip valve that will leak coolant when the bearings go in them.

[Chicagos13]

Coolant level is a little low (just under the minimum mark). I did not see any residue under the water pump, but I only took a quick glance. I'll have to get under the car to really see. Any other ideas or explainations?

[180fan]

have you checked under your radiator cap when the the motor is cold?

[Chicagos13]

Took off the cap and it would seem there is no fluid to be found! Fluid level should be to the top, yes? I don't think there is a coolant leak anywhere. Headgasket is in tact (as far as I know) so I'm not burning any fluid. Not sure if this is entirely the problem, but I feel like an idiot for not looking there first. I was researching a bit and I did think of another symptom. Lately (past week or so) if I turned on the heat it would either blow cool air or blow hot just for a minute then go back to cold - a symptom of a bad water pump. I don't know, sorry for the rambling. I appreciate the help and I know you guys won't let me down. More input? Thanks.

Jon

[Luke]

Fill your radiator up and watch the coolant level over the next few days. If it begins to get lower, you most likely have a leak. I'd go through and check radiator hoses/clamps, radiator drain plug, water pump, and heater hoses.

Check for leaks at the firewall where the heater hoses connect. Make sure they're not leaking from there, which is common after swaps.

An easy way to find coolant leaks is look for a white residue left from the coolant drying up.

[Chicagos13]

Thanks, will do. I'll keep you all posted.

[spider_slayer]

sounds to me like you probally jsut got some air in your cooling system. there is a bleeder screw on the exaust mani....fill the radiator all the way up and un screw that bleeder screw till a little bit of fluid bribbles out.

[Chicagos13]

Haha...

[Tx-Sx-FS]

not to thread jack..but my car seems to overheat way to much and goes too high...at first my car would run fine, at the second mark on jdm gauge cluster..but recently it goes up, drops back down, goes all the way up and stays up. im changing the thermostat tomorrow. But what else could cause this if not the thermo..also, im using the stock ka radiator so the top hose gets pinched some (from cold pipe) when i close the hood. Ill be getting a koyo tomorrow too hopefully.

[Nismo_Freak]

Doubt both of you have an issue with the water pump.

Chicago - I would be willing to bet your issue is a leak under the dash if your heater core is not working properly. If you turn on the heater and the engine starts to cool below normal opertating temp then look first at the thermostat as it's stuck open. Overheating at a standstill typically is due to low coolant, or low airflow through the radiator. If you are using the stock mech. fan make sure the fan clutch itself is still good.

Do not rule out you have two issues though, check the fan clutch and the coolant leak. Don't forget to check the radiator overflow res. for leaks, they are prone to doing that on S13s.

Tx-Sx-FS - Changing the thermostat might be a good idea but that doesn't sound like a fix. Can you explain further how your car overheats and what temp sensor you are using (SR / KA). It almost sounds like a sender unit failure to me.

[Chicagos13]

Thanks for the info Nismo_Freak. Much appreciated. I will definately check the heater core. I probably wouldn't have checked had you not said anything. Good suggestion.