Hi all, I have another small problem. Or maybe not. I finally got someone to tell me how to program my IPC to display the coolant temperature. What concerns me now is it runs 180 to 230, and I usually try to shut it off before it gets to 230 because I do not know what the normal operating temperature is. The cooling fans do come on, and I bought a thermostat, and the upper radiator hose is hot to touch, like you cannot just hold it. I have not put the new thermostat on yet, I just got it today but wonder what the normal operating temperature is anyway. Does anybody know? Its a 1995 Deville with the 4.9 V-8. I thought I read somewhere on one of these threads that the temp that the fans come on at is 200 degrees. Is that so? If it is then maybe my temp is just fine. Any comments or suggestions?

The factory thermostat for your engine is 195 degrees (opens at that temperature to let coolant flow, closes below that to keep coolant in the engine). Without looking I would guess that operating temp is about 210, with acceptable range between 190 and 230. BTW my 85 uses the same tstat and it is usually 190-200 on the highway.

I have a '96 DeVille..had it for about 2 years and it always runs at about those temperatures. Never thought much about it, but I'm assuming it's OK as mine has never overheated. Have to admit, I get a little panicky too when the temperature gets up over 220.

4.9? Anyway, modern engines are designed to run somewhat hotter than in the past in order to increase efficiency. My thermostat begins to open at 188 and is fully open at 206 (hot !) The fan(s) go to slow at 224 and high at 232-234. The engine runs at 210 (temporary remote electronic gauge, STS '02 has no digital readout) all day long on the road, no a/c (fan runs all the time in a/c), and will cycle up to 225 in heavy traffic, no a/c.

Sounds like you're OK. My F150, with a viscous fan clutch, runs about the same temp: 212.

The 16 lb. pressure cap prevents coolant boiling until about 264 degrees.

Alrighty, yeah I have never heard it boil, but just wasnt sure if it was getting too hot. Now I know. I might just put the new thermostat in anyway. Bought it, might as well put it in. Thank you much guys.

Hi all, I have another small problem. Or maybe not. I finally got someone to tell me how to program my IPC to display the coolant temperature. What concerns me now is it runs 180 to 230, and I usually try to shut it off before it gets to 230 because I do not know what the normal operating temperature is. The cooling fans do come on, and I bought a thermostat, and the upper radiator hose is hot to touch, like you cannot just hold it. I have not put the new thermostat on yet, I just got it today but wonder what the normal operating temperature is anyway. Does anybody know? Its a 1995 Deville with the 4.9 V-8. I thought I read somewhere on one of these threads that the temp that the fans come on at is 200 degrees. Is that so? If it is then maybe my temp is just fine. Any comments or suggestions?

Sounds normal to me--my 1995 Deville 4.9 litre runs between 180 to 230 in the summer,between 180 to 215 when i take it out of storage on nice days in the winter.Michigan winters are BRUTAL on any auto here.

my 95 4.9 runs 200 while driving and doesnt go past 223 sitting. ive got new t stat, new radiator, new water pump, and new radiator hoses