New Engine running too cool

[white_97_GT]

hey guys, i just finished building a 331 for my 90 lx, it doesnt want to get up to opperating temp. guage reads no higher then 140-150 degrees even after long city drives. i already tried replacing the thermostat (tested both the new one and the old one, both work fine and didnt fix the problem) i also replaced the rad cap, thinking if its not getting enough pressure buildup it could be causing the cold readings, it now gets to 140 quicker, but no higher. i dont think its just the guage as i can put my finger in the coolant when its up to temp and not get burned. its got a stock replacement water pump and a stock clutch fan aswell.
any ideas?

 

[mustangmutt]

Borrow your wife's of mom's baking thermometer and measure the temp with the engine at it's hottest reading. I'm asuming you have been able to get the rad cap off without spewing coolant everywhere if you can stick your finger in it. What T-stat are you running?

 

[white_97_GT]

I havnt tried to take the cap off after running it since I changed it. The t stat is a 180

 

[HISSIN50]

You might wanna interpolate the ECT if you don't have an aftermarket gauge.

If your engine is cold and you remove the rad cap, when the car starts, do you see coolant moving from the passenger side towards the driver's side of the radiator? If it is, the stat might not be fully closed. Of course, be careful of spraying coolant, moving parts and other safety concerns.

 

[Gearbanger 101]

I havnt tried to take the cap off after running it since I changed it. The t stat is a 180

There's part of your problem. Put the stock 195 back in there and don't look back. Dropping to a 180-thermostat really isn't gaining you anything but longer warm ups, higher emissions, shorter oil change durations and higher fuel consumption.

People are under the mistaken impression that the lower the coolant temperature, the more power your engine will make. Unless your engine is overheating because of large horsepower or displacement gains, there should be no reason for you to change your T-stat at all. Obviously your 331 isn't creating enough additional heat to warrant it.

The previous owner if my car had a 180 in there and I could barely get any heat out of the car. The gauge barely got into the normal ranges, mileage suffered and I could always smell raw fuel coming out of the tailpipes. Swapped it out for a stock 195 when I did my electric fan swap and haven't had an issue since. Car runs better, more heat, cleaner exhaust.

 

[white_97_GT]

There's part of your problem. Put the stock 195 back in there and don't look back. Dropping to a 180-thermostat really isn't gaining you anything but longer warm ups, higher emissions, shorter oil change durations and higher fuel consumption.

People are under the mistaken impression that the lower the coolant temperature, the more power your engine will make. Unless your engine is overheating because of large horsepower or displacement gains, there should be no reason for you to change your T-stat at all. Obviously your 331 isn't creating enough additional heat to warrant it.

The previous owner if my car had a 180 in there and I could barely get any heat out of the car. The gauge barely got into the normal ranges, mileage suffered and I could always smell raw fuel coming out of the tailpipes. Swapped it out for a stock 195 when I did my electric fan swap and haven't had an issue since. Car runs better, more heat, cleaner exhaust.

i dont see how having a thermostat that opens at a hotter temp will help my car run warmer. it doesnt even get warm enough to open the thermostat

 

[white_97_GT]

You might wanna interpolate the ECT if you don't have an aftermarket gauge.

If your engine is cold and you remove the rad cap, when the car starts, do you see coolant moving from the passenger side towards the driver's side of the radiator? If it is, the stat might not be fully closed. Of course, be careful of spraying coolant, moving parts and other safety concerns.

when i tested the thermostat before putting it in it was closing and opening properly. and this might be a stupid question, but what does interpolate the ECT mean?

 

[HISSIN50]

Measure the voltage of the ECT when your car is warm [as warm as it gets].

Does the t-stat have a lot of bleed holes?

 

[Gearbanger 101]

i dont see how having a thermostat that opens at a hotter temp will help my car run warmer. it doesnt even get warm enough to open the thermostat

Assuming of course your gauge is measuring correctly. For $10, what have you got to lose?

 

[white_97_GT]

Measure the voltage of the ECT when your car is warm [as warm as it gets].

Does the t-stat have a lot of bleed holes?

No, just one

 

[jdb3rd]

Borrow your wife's of mom's baking thermometer and measure the temp with the engine at it's hottest reading. I'm asuming you have been able to get the rad cap off without spewing coolant everywhere if you can stick your finger in it. What T-stat are you running?

Are you saying his mom or his wife are gay or both?

 

[Rick 91GT]

Sounds like a very efficent cooling system.... your lucky.

How much antifreeze is in the car? Try running a higher mix of distilled water....less antifreeze. Is this an aftermarket Alum rad, if so you need a cap that has around 20psi. Is the A/C still on the car?

 

[white_97_GT]

No a/c. Stock replacement rad. Tried a 13 psi cap and a 16 psi cap aswell
Coolant to water ratio is about 1/3