Never heating up to operating temp

[X1Nightmare]

Hello all, got a quick question about the engines in these cars, its for the 95 3.8L. I have noticed whenever I drive this car that it never gets up to operating temp. Honestly it barely ever gets up past the bracket range for normal. If I let it idle, it will raise up to normal operating temp, the fans will still kick on and it will circulate like normal. My thinking for this is that one of the owners in the past put a 160 degree thermostat in it, and with as cold as its been it isnt allowing it to heat up enough before it starts circulating the coolant. Just kinda wondering what your alls opinions on this may be?

 

[white95]

Its possible the thermostat is stuck open and doesn't allow it to heat up. Just open it up and investigate.

 

[RichV]

^+1

Thermostats typicaly have the rated temp stamped on them. Yank it out and check, maybe get the correct one just so you could swap it if necessary. If you're by chance in CO, LMK, I have like 5 good ones in my garage from various builds.

 

[chrisv_10]

Yeah it's probably a lower temp thermo or like mentioned above it could be stuck open. Pretty easy to remove and install. Gasket and thermo are pretty cheap.

 

[MustangChris]

throw a pot of water ont he stove and throw your theromstat in it. Watch the temp of the water and make sure it opens when its supposed to.

 

[99GreenStang]

New thermostat for sure . and a hotter one .

 

[CC'S95GT]

you guys are missing the point that the fans ARE kicking on.
Are you getting heat out of the vents?
YES- then the thermostat is working and the temp sensor for the guage or guage itself is outa whack
NO- Thermostat is stuck open or a lower temp or missing and the engine temp sensor is is faulty and telling the fans to turn on early

 

[joekd]

Can you hear the fans turn on? Just want to be sure they are not running all the time.

I wouldn't bother testing the thermostat, if you are going through the hassle to remove it just buy a new one and put it in. Also buy all new coolant so you know everything has been done.

 

[DeepList]

Thermostat stuck open is the most common cause of this.

I wouldn't bother testing the thermostat, if you are going through the hassle to remove it just buy a new one and put it in. Also buy all new coolant so you know everything has been done.

^ I agree with this. If you go through the hassle of taking it out, just replace it. They're pretty cheap.

 

[99GreenStang]

You guys missed the point I made in my post .. I said a new thermostat and a HOTTER ONE!! < KEY WORD ! The thermo is too low of a temp this is causing the coolant to circuilate to soon and thus keeping it too cool .. put a 180 or 190 in it and this will fix your problem . SOURCES : PAST EXPERIENCE HOW MUCH : PLENTY OF IT

also the reason it is running hotter at idle like anything when your moving its sucking the air in thats coming through the radiator and the fans pulling it .. while idling its just pulling air in like anything at idle it will run a little hotter than if you were moving . hope i help .

 

[CC'S95GT]

Stock thermo is 180*.. There is absolutely no reason he should need to go hotter.
Most everyone is saying it's the thermostat and hopefully it is but I doubt it.
BUT. as he said in the first post " If I let it idle, it will raise up to normal operating temp, the fans will still kick on and it will circulate like normal." that tells me the thermo is operating correctly and the temp sensor for the guage in the car is not reading correctly.
Remember, there are 2 temp sensore for our cars. 1 for the computer and 1 for the guage.

 

[Buicknick72]

Stock thermo is 180*.. There is absolutely no reason he should need to go hotter.
Most everyone is saying it's the thermostat and hopefully it is but I doubt it.
BUT. as he said in the first post " If I let it idle, it will raise up to normal operating temp, the fans will still kick on and it will circulate like normal." that tells me the thermo is operating correctly and the temp sensor for the guage in the car is not reading correctly.
Remember, there are 2 temp sensore for our cars. 1 for the computer and 1 for the guage.

That's how a car acts if the T-stat is stuck open. Idling and even low speed city driving will allow the engine to get up to operating temps- with none or little air moving past the radiator, it has little cooling effect allowing the car to warm up. Once you start driving the radiator is cooling the coolant, and with a stuck open t-stat the cooling system is working at 100% and will bring the temp down as much as it could. With older cars that have mechanical fans a stuck t-stat never allows the engine to warm up, even at idle since the radiator has cooling effect.

I've had plenty of stuck t-stats, and that is stuck. Or installed backwards, install the new one how it says to regardless of how the old one in installed.

Also if it had a 160 in there and it was working properly at 160, the engine would reach 160 just as quick as it would reach 160 with a 180 tstat. Only difference is it would stay at 160, but would never go below 160. So the needle on the gauge would just be on the low side, but would be relatively consistent.

 

[99GreenStang]

Thermostat is too cold! ! Change it there only like 4 bucks !! Make sure as mentioned its not installed backwards very easy to do .. Even new thermostats can be bad and he said the previous owner changed it for a 160 that's why I said hotter which I believe he still needs to do . That's the reason it heats up at idle , cars get hotter at idle and cooler when moving that's why it works perfect at idle , but when he gets moving and it starts drawing in extra air it cools it down so much that it goes way below operating temperature and he loses performance and heat by it doing this . Buy a new 180 if there's a 160 in it and throw it in there job done . Bada bing bada boom