My car is having an issue at stop lights... The temp go's from 180° to around 220° at stop lights.. it instantly go's back to 180° when I start moving... What could be the cause ? Its a belt driven fan 180° t-stat 302ci ... My thought is t-stat is stuck open... What's your opinion ?
Do u have a fan shroud? 40 degree increase at a stop light is a bit much by my standards. I'd be more inclined to expect that in 95+ temps w/ ac running.
Yes factory fan shroud, no ac... This just started happening, before a couple days ago it never went over 190° no matter how long I sat in traffic... Also a aluminum rad and 50/50 coolant... No leaks and coolant level stays just above the fins...
Do you have an electric temp gauge? If your idle is too slow, the alternator doesn't put out the same volts, so your gauge will read incorrectly! See if speeding up the engine slightly helps. If this is what it is and the gauge is electric, the reading will change almost instantly.
I would try a thermostat..... and I would get a decent quality one not the elcheapo deluxo, I have seen a couple problems with the cheap ones recently.....
Could be the water pump impeller is either slipping on the shaft a bit or corrosion has eaten part of it away. At low RPM's, not enough flow to cool, then at higher RPM's, it cools fine.
My water pump has a lifetime warranty, I bought it in 2006 ... I'm going to replace the water pump,t-stat and fan belt and see if that helps...
You could idle it with the radiator cap off and check the coolant flow on idle. Your fan isn't on backwards, is it?
If you are running a clutch type fan, a worn out clutch could cause higher temps when the car isn't moving.
No fan is on the right way... It was perfect for over 11 months even through the florida summer... this just started last week....
I would speculate the temp guage first before the water pump or the thermostat. As stated earlier, check the radiator to see if the coolant is flowing while the motor idles. I really doubt it is the water pump.
