Water Temperature Gauge

[Mustangbelle306]

Hey guys! This may sound like a REALLY stupid question, but here goes!

We just installed my phantom water temperature gauge, and I was surprised to see that my engine was running at ~200 F, even though on the stock gauge it was sitting around the "O" in normal. So after installing 160 F thermostat, it still idles around 195-200 F, but at highway speeds it sits comfortably between 170-180.

I understand that at higher speeds the incoming air will cool the engine, but shouldn't it be running at 160 at that point? And is a 20-30 degree difference between idle and cruising normal?

Ah, all the questions a more accurate gauge creates!!

Thanks in advance for the help!

Belle

So after installing 160 F thermostat, it still idles around 195-200 F

try switching to a 180 thermostat,the 160 never keeps the coolant in the radiator long enough for it to cool down.

[drudis]

Stock, I believe, is 195'F thermostat.

Depending on where you mounted your gauge too... I mount mine on the driver's side front of engine. I get consistent temps there. I have a 180'F (wouldnt recommend lower as it screws up your computer into rich...). At idle its a little warm (underdrive pulleys), but on the street its rock solid 182'F. At the track I never go over 205'F with the big Griffin radiator.

[lx mike]

I have a 180 thermostat in my car and on my autometer gauge it is almost always between 178-182 degree's. even at idle never goes over 182 and soon as car starts to move it drop down belwo 180.


I had an late 60's camaro and on the highway or just sitting it would run around 190-195 with a 170 thermostat, around town at lower speeds would run 170-180.


here's my .02 on the matter. no matter what thermostat you have in the car the cooling system can only get rid of so much heat from your engine.

[Mustangbelle306]

Runs rich? I was actually shocked to notice that my car is running LESS rich, seemingly after the thermostat install

I've been having recent trouble with gas fumes and TERRIBLE gas mileage, and for the first time since installing the new engine, I got decent MPG driving back to school this weekend (like stock engine numbers). Truthfully, I had NO idea why but was hoping it had something to do with the thermostat...

Or maybe the hamster under the hood finally got **** straightened out

[lx mike]

Or maybe the hamster under the hood finally got **** straightened out

just one? that your problem then, the little guy is having to do too much work on his own! the more you can squeeze under there the less workload each has to do. put a male and female under there and soon that car will be flying from hampster power!!

[Mr 5 0]

Originally posted by Mustangbelle306

...after installing 160 F thermostat, it still idles around 195-200 F, but at highway speeds it sits comfortably between 170-180.

I understand that at higher speeds the incoming air will cool the engine, but shouldn't it be running at 160 at that point? And is a 20-30 degree difference between idle and cruising normal?

The thermostat opens at 160 but it won't close up again on a normally running engine. When you idle - and have no airflow - the temperature will naturally rise, then drop when the airflow increases. As you have a modified engine, it will run somewhat hotter than 'normal' at idle.

Just as when you drive normally and shut the engine off for five minutes then re-start, you'll see the temperature somewhat higher than normal as the remaining engine heat is trapped in the cooling system with nowhere to go until it can just naturally cool down.

An electric fan would give you lower idle temperatures, if this is a real concern.

[Mustangbelle306]

My car came stock with an electric fan...I can upgrade to a Black Magic for $200 though.

I think I might just go back to a 180 stat...that's what it had stock, and I think it runs about the same at cruising speeds anyways. The shop said exactly what Mustanguy did, so I guess I should have just left well enough alone!!

I guess I'm just mod-happy

[Green9550]

The reason why your car is getting hot just idling is because the fan does not come on till a little over 200 degrees. When you are going down the road there is air going through your radiator. A thermostat just makes the water enter the engine at a lower temp. If you want your car to stay at 180 degrees then you will have to buy a chip that makes the fan come on sooner or hard wire your fan so you can turn it on and off at your discretion. The stock fan is very good on our cars, don't waste your money on another one. Hope this helps.

-Billy

[Mustangbelle306]

Thanks for the explanation, I knew that and I agree about the fan too. I'm currently looking for the switch panel that installs in our stock ashtray so I can turn that bad boy on at MY discretion

The shop said exactly what Mustanguy did

The thermostat I put in my Holley equipped 85GT was a 160
neva overheated

[PKRWUD]

Times change. A year ago I was getting ripped by people who refused to believe that a lower temp t-stat can cause an engine to run hotter. I'm so proud.

Install a 180.

Take care,
-Chris