When I idle in hot weather for longer than a few minutes, the temp gauge goes to 220, and the car gets lazy, not really losing power just slowed reactions, annoying but not serious. It did this last summer too, except in that case, by the late fall it was going over 220 and staying there. I changed the stat to a 180, which *seemed* to fix the problem instantly (and the temps were glued at the nice-behaving, cool 1/4 mark.) Could the stat have gone bad already? The problem's not bad *yet* because it will not go over 220 and it also seems to 'cool' or improve, when the car is moving. I think the car has *always* done this when idling hot and talking to some people it seems like it's normal and other people say it is *not* normal and there is another reason for the car to heat up and get 'lazy.' What are some usual suspects? Just visually, there's nothing with the air dam, or on the radiator, no leaks, burning stuff, etc.

 

It's normal for a TG with electric cooling fans. At idle with no airflow from the deflector the ECM kicks the primary fan on at 220-225 degrees, aux fan at 234 assuming you have dual fans. Single fan will still come on around 225 or so. You can lower the fan turn on but in hot weather all it or they do is cycle constantly eventually frying the alternator. Some people claim a different "feel" when the engine gets over 200 and I believe there is some truth to that, but it's probably more from a change in oil viscosity than anything else. A good synthetic oil makes more sense in hot weather since it retains viscosity over a wider range of temps. Since you are out in CA you may want to also try more water/coolant, instead of say a 50/50 mix use a 70% water, 30% coolant ratio. Coolant does very little at the high end of the temp, water is the primary agent.

 

Cool, I was just wondering if there was a real reason for it. I get bored sometimes on those rare occasions when there is nothing broken on the car, and I start to imagine things too. I wondered about the oil because I change it often and always use different brands and types and it sometimes I imagine there is a difference and now I know why.

 

It ended up not being a coincidence. The temps (indicated by the gauge) kept going up until today, when they were well over 220, and finally noticed the driver's side fan wasn't working properly, (it was trying but barely moving. )

 

Hey Julie where in OC are you? Come check out the So Cal board. I'm always happy to bump into fellow So Cal thirdgenners.