s13 sr20det overheating w/ new pump + thermostat

[s14kozenki]

Hey all thanks for the help with bleeding the lifters... but now I have an overheating issue...

Note: this is an s13 redtop in an 1995 s14.

after looking through various overheating threads here and elsewhere, I have attempted to bleed the coolant system several times, have installed a new OEM water pump, and a new OEM thermostat. Heater hoses are hooked up as follows:
hose from back of engine with the water outlet to turbo: hooked the U shape hose, to L shape hose, to heater controller module thing hanging inside engine bay. This is the HIGHER of the two firewall heater hose connectors.
hose from underneath throttle body: hooked up S shaped hose to the LOWER firewall heater hose connection. neither of these hoses have visible kinks.

The heater does NOT blow hot air when I run my engine. The car overheats in about 2 minutes of idling. The coolant in the radiator does not seem to be flowing, but is almost stationary, even after massaging the lower hose. Coolant reservoir tank is half fillled, and radiator is almost topped off, car is on jack stands pointed upwards at the front like I have read in other threads. I am afraid to let the car idle for so much longer since the temp gauge is practically over the H. I have used the bleeder screw on top of the outlet neck as well but the car overheats so fast I don't have a chance to let it idle for a long time. don't wanna warp anything.

I would replace the temp sensor for the interior gauge cluster, but that still wouldn't solve the coolant not flowing in my system or the heater not blowing hot air.

This is all the information I have, if you have any insight or need more info please let me know.

again note: the water pump and thermostat are brand new OEM nissan units, and there is only one real way to install them so I do not believe it was an installation error on those two particular parts. the chances of them going bad are slim to nill people tell me.

thanks!
kevin

[s14unimog]

Hey Kevin, nice description... people should take note when posting technical questions...

I would check a few things.

1. Make sure the bleed hole on the thermostat is at the top. With the car off you should actually be able to hear the check valve in that little hole "click" while you squeeze and release the bottom radiator hose. When you bleed the engine, you should have the lower line off the thermostat housing, but still connected to the radiator, and as high as the length will allow it. Fill the radiator up until you see water coming from the thermostat housing. After that happens, put the lower line back on but allow a little gap so that you can fill that little area; still spilling out and filling from the radiator. Once you are convinced that area is filled, shove the line back on and clamp it back down. Keeping the nose of the car in the air is a good idea too.

2. Since your car is a 95' you might have the valve in the engine bay for the heater core. Make sure that valve isn't closed.

3. Did you switch temp sensors on the SR20 for the interior gauge. If you use the SR one, the 240sx cluster will read high always.

GL and I hope this helps

[s14kozenki]

Thanks for the help s14uni. I have read about the temp sensors being "chassis specific" So i'm pretty sure I need to change that out (if that info is correct). The heater worked before the install, but of course maybe i hit it with the engine while swapping motors..will check the heater valve and make sure its not stuck and bleed the engine again using this method.
kevin


edit: alright took out the thermostat to see if that was the culprit.. and it seems like it was. I still want to get a new temp sensor for the interior gauge though (also getting an autometer water temp gauge). Anyone know how long I can run without the thermostat? or if it is even bad for the engine? cause clearly my engine has no problem getting to and beyond normal operating temps -__-

Without the thermostat the car runs at normal running temps as displayed by the cluster temp gauge, however the car does slowly overheat over a period of about 10-20 minutes of test driving around my neighborhood. My fan currently is only set up to run on low, so I'm gonna wire up the high setting now and see if that will finalize my cooling issues.

edit edit: BTW I have the hood off the car at the moment from the swap. could this have a negative effect on cooling efficiency of the fan/radiator? I would think "more air", but then again it might not be flowing correctly without the hood.

[s14unimog]

If you have the SR20 single wire temp gauge then you will always read high.

You need to go buy the single wire sensor for the KA and install it. Running around without a thermostat is never a good idea. The ECU makes changes based on the temperature of the engine.

[lilrusty]

you NEED the s14 ka temp sensor i believe they are different voltage (someone correct if im wrong) from red top to kade s14. at least thats what i always heard.

[s14kozenki]

Would it be possible to nab the sensor off my old KA and use that? Seems like it would be a direct fit, will attempt today haha. And yea I have heard about drilling holes in the thermostat, but since it's probably just the temp sensor that is fooling me into thinking the car is hotter than it is, perhaps it won't be needed after all.
kevin


edit: problems solved.. moving on to slipping clutch issue.. thanks for the help guys!