Overheating!?!

[blanchardkeith]

I have a 75 spider. Driving is fine, temp is right in the middle. When I stop at lights or traffic jams it does not take long for the needle to start climbing. When it is truly warmed up after driving in houston heat for 1/2 hour it probably doesn't take more than 5-7 minutes before I get failry worried of overheating? My fan comes on, have replaced the temp. sending unit. Could it just be the water pump or whole radiator?!? All thoughts are appreciated.
Keith

[mbouse]

well, if the fan is kicking on, my first thought is NOT air in the system.

could use a good radiator flushing, cleaning or replacement. The pump should be working fine, unless you hear unbearable screeching like a banshee, or gushing leaking from the pump.

[racydave]

Id probably start off with a good flush of the system. Its possible someone has not properly maintained it. Also if the ignition timing is over advanced itll run hot. Is the belt slipping? Is the cooling fan runnin in the correct direction? Is there dirt in the rad fins? Do you have the correct rad cap ( pressure wise )? Does the heater blow hot air? Is the coolant mixed at 50%?

[So Cal Mark]

overheating at idle is not a water flow problem, it's lack of air cooling the radiator. Daves' suggestion to check the fan is a good one. With it idling, wait until the fan comes on, then feel the air coming through it. It should be hot and blowing back towards the rad. The next step is to get an infrared heat gun and test the actual temperature; inaccurate gauges are common

[mbouse]

It should be hot and blowing back towards the rad.

Mark,

this statement has been bothering me for quite a while. Perhaps i am just reading it wrong, but every radiator fan that i recall watching in action sucks air thru the radiator and blows the air away from the radiator... otherwise it is working against the natural flow of the air around and thru the radiator while the car is in motion.

exceptions are radiators not in the nose of the car, and fans in front of the radiator.

i specifically looked at the directional arrow of a Fiat Spider radiator fan. if you look at the nose of the fan, the arrow points clockwise...and the fan blades rotating in that direction will pull air thru the radiator, not push air back towards the rad.

[So Cal Mark]

Hmm, my brain and hands didn't quite communicate very well on that statement. What I meant was the the hot air should be blowing back from the radiator, which would be towards the engine. That's what I get for typing while eating lunch

[mbouse]

musta been that possum pie.

[rlux4]

Possum pie!! I share my tater salad with you Mark, and you don't call me when you have Possum pie?
Ron