Car always runs cool. Problem?

[MrWampus]

Since the day I bought "The Mistress" she has always run quite cool according to the temp gage. My first spider always ran right at the mid point except when it was overheating, which was frequently. The Mistress always runs just above the cold mark even in warm weather, except if I'm in really heavy stop and go traffic the needle will get up to the mid point. The fan cuts on and off in that circumstance as it should. I'm guessing either the thermostat is stuck open or the temp gage is faulty or the previous owner did something to keep it from overheating. My real question is does it do the engine harm to run that cool (if it really is) or should I address the issue?

[vandor]

Sounds like the t-stat is stuck open. The FI system will run richer if the engine is not up to full temp, so you are loosing mpg.
The heater will not work as well as it should, but this may not be an issue for you.

[MrWampus]

OK, that's what I was suspecting, stuck open t-stat. The mpg is a little lower than I would expect, something like 23-24. I thought I remembered getting somewhere between 25-28 with my last one. Asisde from the lower mpg and less efficient heater though, I'm not doing any long-term damage to the engine? I'll get around to fixing it one day, just trying to prioritize.

[124JOE]

one of our tricks is to drill a 1/8 hole in the stat
maybey they went a bit bigger

[4uall]

I found the reverse (overheating) however, there was an internal thermostat in the head that was stuck closed. So perhaps the reverse is happening for you? see photos on my sig

http://wwwe.fiatspider.com/f08/viewtopi ... =5&t=16398

[So Cal Mark]

engines like a constant temp and of course the oil needs to get warm enough to burn off any contaminents and moisture.

[zachmac]

Most likely is a stuck open Tstat as others have said. You should indeed fix it as FI cars like to run at full operating temp. but it shouldn't hurt anything if you wait.

There is also one other possibility, a PO might have installed the hose T connection at the block backwards. The T has a wide open side and a much smaller (orificed) side. The orificed side should be facing the t-stat, wide open toward the radiator. This is to promote fast heat up. But, even then they usually still heat up eventually. Sounds like stuck T-stat. I just replaced my stuck closed one with one of the less exepensive units several of the vendors offer and it works great!