overheating. countless hours searching...

[whoareu]

i know this topic has been exhausted but i am haveing overheating issues. My cooling setup is a godspeed radiator with dual fal220 fans. i also made cooling panels to keep air from escapeing between the fans and radiator. i do have a huge fmic that takes up most of the front. but i cant for the life of me keep the car from under 3/4 of the temp gauge. i will be getting a autometer temp gauge soon but dont have one yet. the car idle's at 1200-1500 according to the safc and i know it needs a tune and an adjustable fpr. my fpr is 40 w/o vacuum. when im high up in the rpm band the temps go down but if im not revving im overheating. and i have bleed the coolant numerous times. i am really beginning to think it is the water pump, but the guy i bought the motor from replaced the pump himself. when i try to burp the coolant system i cant really see it flowing through the radiator, but it will go down a little and then just starts overflowing at the cap. does that mean its the thermostat? im freaking at wits end here. and i have seriously searched this forum and others to find answeres to my questions but cant really find anything like what i stated.

[Joe]

change the tstat for cheap insurance but it wouldnt be the first pump to grenade itself in a Rb.

[whoareu]

so it sounds more like the pump to you? reason i ask is because it will run at normal operating temp and then after say 10-15 minutes the temps start creeping up if i dont keep her up i the rpm's

[Joe]

could definitely be a pump, or a blockage.

[streeteg]

From the sound of it it looks like you do have blockage or your thermo might be sticking.

I have a nismo thermo if youre interested--shoot me an email if your interested.

[email protected]

[s14_sport]

before making any changes to your setup....try bleeding the coolant system again.

It took me a good 45minutes to an hour to completely bleed my system the first time I got the motor running.

car jacked up in the front, rad cap off, motor on....keep refilling coolant as necessary

[Initial_R90]

pressurized coolant flush , thermo, take the pump off and check it out

[whoareu]

when i try bleeding the system it always overflows. then when i turn the car off it eventually settles and i refill it. it has a greddy IM if that makes a difference.

[whoareu]

pressurized coolant flush , thermo, take the pump off and check it out

cant you check the pump out with the thermo removed?

[gawdzilla]

might be a dumb question but i'm surprised no one has asked this.

What sender are you using to your water temp gauge cluster? If you are using the RB sender the gauge cluster will read wrong (show hot when it really isnt)

[jrb92se]

i have a rb25 it took me about an hour to bleed my system you have to go get the kit from discount auto with the big yellow funnell. it never worked for me just jacking the car up i had to use the funnell and then jack it up . but other then that i think your thermo is stuck, just my opinion. did the previous owner replace the stat with the pump? ive heard and read a few times that the rb series of engines can be bad with having bubbles n the coolant. also i use the rb25 temp send with the oem 240 gauge it reads accurately.

[jrb92se]

mod delete please it posted twice.

[95RB20S14]

I had an overheating issue so I replaced the thermostat with one from a 300ZX and it fit fine but it was not opening. I removed the thermostat and it cooled fine. You have to put the thermostat in just right or I think its easy to bind it up. Check your bottom hose and see if it ever gets warm. If it stays cold when the temp is up then I'd say that's your problem.

[whoareu]

it gets hot. im thinking my thermo may be stuck open.