Re: Lifespan of a thermostat
There are two sensors on the thermostat, one goes to the ECU to tell the engine whether it needs to inject more fuel(as far as I can make out) to assist warming up as it'll run rich(like using choke on an old carb car) and the other sensor tells the dash what's going on that you can see on the gauge. Just because the dash says XX degree's, it doesn't mean that's what the ECU is seeing. The only accurate way to tell is using a temp probe or hooking the car up to the diagnostics machine to see what the ECU is seeing the temp as being.
The car should normally warm up within 10 minutes or 5 miles or so, but I would guess the ambiant temperature plays a big part in this. I've been driving to work in the morning at around 6 o'clock when the temp outside is freezing and it'll take up to 15 miles to get up to temp, then when the stat opens it drops back to about 70 or just over. When I come home from work the car gets up to temp after about 10 mins or so as the ambiant temp is higher and therefore the car warms up quicker. I think the thermostat opens at something like 87 or 92 degree's depending on which engine you have.
If you put your hand on the coolant hose going to the radiator when the car is just started, it shouldn't get hot for a while as the thermostat will remain closed not letting the coolant get to the radiator. If the pipe to the radiator starts getting warm quickly, the thermostat is open and letting the coolant go around the whole circuit(including radiator) which means the car takes longer to warm up. This means you need a new thermostat.
Last edited by Mark_JTD; 09-12-08 at 11:57.