Thread: Running hot where to start?????

Ok guys need some help here. I've done a 180 therm a while back while I was doing wires and plugs. I noticed the my gf's car is running a litte to hot for comfort IMO but I'm not sure where to start. I probably didn't bleed the air properly when changing the the therm so I'm might start there. The cooling fans work but only when the computer tells them to when the temp is high. Also it climbs quickly at a stand still like a red light, drive through, etc. But once your up and moving and you get air flow across the rad it starts to cool down. Where do I need to start? Thanks in advance.

Everything I can find tells me you should be running a 195' Thermostat as OEM on the 2003 ?

So why the 180' ?

Found this info very interesting, thought I'd share.

The thermostat is much maligned, often misunderstood, and seldom credited for its mostly reliable service.

Thermostats in proper working order, control only the minimum operating temperature at which engine coolant is allowed to heat. A properly operating thermostat has absolutely nothing to do with how hot the engine becomes. If you are experiencing an over heating engine, changing to a colder thermostat will not correct the condition, it only allows the coolant more time to over heat. A thermostat once fully open can do no more to control temperature. The overheating cause lays somewhere else.

Some believe that removing the thermostat completely can remedy over heating concerns. This can be deceiving, with out some flow control coolant can pass through the radiator without slowing enough to cool, returning to the engine hotter with each circuit of the liquid.

The temperature stamped or marked on the thermostat is the "start to open" rating. This is often referred to as when the thermostat just "cracks open" and allows some coolant to flow. This is in contrast to the popular belief that the temperature specification identifies when the thermostat is fully open. Most applications have a thermostat that is designed to "crack" at about 180 to 195 degrees F. If the thermostat opening is set too low or too high engine damage can be the result. High coolant temperatures can cause abnormal combustion, loss of power, damage to bearings and other moving parts, etc. Low engine operating temperatures lead to excessive fuel consumption, dilution of lubricating oil by the addition of unburned fuel, the formation of sludge from the condensation of water in the crankcase along with a host of other concerns.

Thermostats are designed to be fully open 20' degrees F after cracking.

So 215'+ on a 195' would be considered "Normal" as on my 2006, and the fans dont even come on till 230'

Don't know how hot would be considered Too Hot, seen other post asking that, Maybe someone more knowlegable will chime in on that. So long as the pressure is holding the temp can go pretty high before there is a real problem.

I had a 180* in mine, and in 100degree + weather I would run 185 all day long. Comming to a stop light, I might get up to 200* at most.

One instance after flushing the system, I didnt bleed it properly, and it wasnt totally full, so I would hit close to 215* when I came to stops, and like you said, would cool back down when you started driving..

I'd crack the valve and see if you cant bleed it a little better, and add some more fluid, and see if that helps.

Could also just be a fault CTS. Have you hooked it up for diagnostic and see what the actual running temperature is? And put the 195* back in, all your doing is wasting money on fuel. You can get a tuned PCM that turns the fans on earlier, and offers more than that.

And the answer to the problem is.. "it's normal"

Low speed fan is programmed on at ~216F
High speed fan is programmed on at ~228F

Unless your pcm has been changed for a lower thermostat, the minute you get off the highway or stop in traffic. Expect temps to rise.

I had a similar problem like this when I did my LIM. Just try bleeding the coolant through the thermostat again. Fixed my problem.

Bleed the radiator the old school way with the car jacked up and the rad cap off.
If there is air pockets in your heater core the goofy bleeder on the thermostat won't get it.
Usually people with the 180Tstats have the fans tuned to come on earlier, so if you're running one with the stock 195 fan settings that is probably why your temp spiking a little.

you always burp the system of big air pockets with the radiator cap off.....or at least i do...