Where should I start in diagnosing the problem.

When I'm in traffic the temp gauge goes up, sometimes all the way to hot. but nothing relaly looks wrong, doesn't smoke open the hood, the over flow tank on the radiator is at a normal level.

As soon as I start driving, and i mean within a few seconds, and theres some air flow, the gauge drops down to normal.

When I last took it to the dealer I know the servce managaer well beacuse he works on my S2000, I had him look at it, and he said that they let it sit there running for a half hour and they didn't notice it move.

But on my way home, I saw it go back up again in traffic. Something's not right, any help?

 

wait....do you have an oil temp gauge? Or are you talking about your water temp gauge in the car?

 

If it's the water temp gauge you might need to bleed the coolant, this has happened to me before.

 

I second on water temp... Unless you installed one, I don't think it will be an oil temp.

Anyway, if the temp fluctuates after the engine is warmed up, make sure the radiator water level isn't low. If it looks ok, grab a $10 thermostat and replace it. Pretty easy to do and cheap. Frequently, the thermostat will develop a "catch" spot in it as it wears. This causes it to stick or be sluggish to react.

Easy to do and it will build self-confidence in your mechanic skills.

 

Oh - There are two electric fans. One should cycle on/off as you are driving. It should especially be on if the temp is above the mark to the right of center on the guage (about 195 deg F). You will easily be able to hear it running.

The second fan will come on when the airconditioner is on. If the fan is dead or the fuse blown, you will definately have cooling problems when moving slowly or in stop/go traffic.

 

yeah, if its fine while driving but hot in traffic i'd have to say a fan. thermo won't allow the fluid to flow, and when its stopped its not getting hot enough to heat up. but when driving at low speed, not enough air flow across the radiator to cool it, but enough load from the engine to heat the coolant

 

sorry, yes i do mean water temp gauge

 

I'm going to dobule check the fan. if that seems to be working fine then I'm going to go after changing that thermostat.

Is that something i can pick up from like autozone? and if so how much should it run? was that the $10 bucks or so as quoted above?

Also does anyone know if theres a write up anywhere online on how to change it? Hopefully the service manual at least explains it a little.

 

It is pretty easy to do, service manual explains it all... don't get the cheap theromo ( i think autozone has two options). On the same topic if ur fans are coming on when they should, what would u diagnose first? thermo sensor?