SR20 overheating just when idling

[HoosierDrifter]

i have a 92 240sx with the redtop sr20det and i took it out for the first time in a couple months today. while i was sitting at the bank drive through, i noticed my temp gauage was almost spiked. the electric fan was on. as soon as i would take off driving, the temp would almost immediately go down to normal... any ideas?

[Tuner]

Flush your coolant, change your Tstat

[sdtouge]

bleed coolant, check water pump hole for leakage. thermostat wouldnt be a bad idea go to nissan for thermostat you want oem not kragen 4$ special that never works right.
also check coolant temp sendor? it could be bad making your gauge wrong. also if it really is overheating youll want to do a compression test as alluminum head can warp somewhat easily.

[Tapethejunkie]

did it feel like you were runnin outa gas? cause i had the same prob and my fuel filter was in parts inside, my tstat was old, and my modulator (sp) was fukced and that was the biggest prob

[s13/350z]

i agree with the above 'burp' your coolant and check the thermostat and also flush the radiator I have seen alot of cars that need a simple flush to keep from overheating because mineral deposits and what not in the lines keep the coolant from cooling off fast enough to help the engine...if not it could be a problem with your wiring harness sending impoper signal to the computer then the dash with the sr harness and the 240 dash.

[HoosierDrifter]

im thinking it was a major air bubble. i loosened the cap while it was at running temp, and a whole bunch of air spewed out. so... how do i "burp" or bleed the coolant system?... i think im just gonna go with sdtogue and just flush the whole thing.. i need to make sure theres a 50/50 mix anyway

[HoosierDrifter]

k... its now either a blown headgasket or the head is warped.. i have a feeling its warped cause i hydro locked it once.. fantastic...

[mk3mann]

You have a BHG if you hydrolocked it. Head will always be out of true if you have a BHG....

Ask me how I know about BHG's...

Wow thats pretty rare for an SR20 though....

[aristo]

There's a little screw on the upper water neck that can be used to bleed air from the system. It should have a yellow label next to it.

[HoosierDrifter]

yea... it was a major air bubble, but there has to be a reason that air bubble got there

[aristo]

yea... it was a major air bubble, but there has to be a reason that air bubble got there

maybe the water level just went down or something. Lots of things can happen when a car just sits around for a while.

Check your oil for coolant, then you'll know if it's a bhg or not.