Thermostat:180 deg. vs. 190/192 deg.

[blazer94]

Any opinions on temp rating for the following application: short ( 5-10 min) drives, low speed (25-35 mph) in a 4.3 l cpi 1994. I am currently running 180 deg., yet I am wondering if my engine is gettting warmed up enough. The temps outside are warming, yet my temp gauge (100, 210 300) seems to hover around approx. 160-170 deg. Any input would be appreciated.

[Rick Norwood]

Originally Posted by blazer94

Any opinions on temp rating for the following application: short ( 5-10 min) drives, low speed (25-35 mph) in a 4.3 l cpi 1994. I am currently running 180 deg., yet I am wondering if my engine is gettting warmed up enough. The temps outside are warming, yet my temp gauge (100, 210 300) seems to hover around approx. 160-170 deg. Any input would be appreciated.

If my information is correct, these trucks are designed to run with a 195° T-Stat in them. If you are running a 180° T-Stat and only getting 160°-170° your T-Stat might be stuck open, but in any case, you are running too cold.

There is a theory that in places where the temperature is extreme like in Arizona and southern California that the 195° T-Stat is not needed. But even though I live in Arizona, I have learned my lesson about trying to out smart the Boys in Detroit. Install a 195° T-Stat in your truck. If you have over heating issues, don't blame the T-Stat, this would indicate it is time for a reverse power flush or some other type of cooling system maintenance.

[BlazerBoyLT98]

You engine definitely is not getting hot enough and you will be losing gas mileage without a doubt.

[TonyMazz]

I had a T-stat stuck open and temp was way too low...160 range. The close loop for emissions I believe is 158 so things barely hint the close loop. Hence my MPG dropped like rock to 13-15...installed new 195-degree and the MPG rose back to 18-21mpg.

[blazee]

I suggest you change the stat to a 192/195 and start letting you engine warm up a little before you leave. Those driving conditions can actually double your engine wear:

1. Today's engines operate at high temperatures to fight combustion by-products and pollution. Lowering the temp below 175-180 won't accomplish this.

2. Engine oils are designed to work over a specific temperature range with optimum performance starting at temperatures that require the coolant to be the very same 175ish range.

3.Your engine forms moisture inside when it cools and condensates on the walls of the inside. This moisture then is washed down into the oil when started and then awaits vaporization by internal temperatures rising enough to bring the moisture to the appropriate corrected vapor point (boiling). If enough moisture is left behind it combines with combustion byproducts to form acids that become dissolved in the oil itself. The oil becomes more acidic as the age of the oil progresses and picks on certain parts eventually. Also moisture will corrode other surfaces. So, it's important to get these engines to a satisfying operating temperature as soon as possible. Usually oil pooling temps are about 30 to 40 degrees higher than the coolant temps. This is a generalised statement and can vary with load and engine design but you can see why you want your oil over 212 degrees to boil out the moiture immediately!

[blazer94]

Originally Posted by Rick Norwood

If my information is correct, these trucks are designed to run with a 195° T-Stat in them. If you are running a 180° T-Stat and only getting 160°-170° your T-Stat might be stuck open, but in any case, you are running too cold.

There is a theory that in places where the temperature is extreme like in Arizona and southern California that the 195° T-Stat is not needed. But even though I live in Arizona, I have learned my lesson about trying to out smart the Boys in Detroit. Install a 195° T-Stat in your truck. If you have over heating issues, don't blame the T-Stat, this would indicate it is time for a reverse power flush or some other type of cooling system maintenance.

Thanks everyone for your input, I had a feeling that it would be the case to go back to the 195 T-stat. I replaced the heater core and radiator back in 10/94, and when i did the motor I put in new water pump w/ 180 t-stat. Changing back to ac-delco 195 this afternoon. Thanks again everyone.

Thought I'd tell why I put 180 deg. in the first place. On a sunday, when I changed the water pump (ac/delco), I'd forgotten to get a t-stat. Went to Murrays (they sell ac/delco parts) to get replacement, had to be ordered. In stock was prestone 180, so I figured , eh, I'll run a little cooler, and idiot that I am, and knowing in the back of my mind that 15 deg. does make a difference, (and figuring it was winter, shouldn't make a difference) went ahead and used it. Moral of the story: never take a fools ( my own ) advice without consulting others!

[excheezhead]

Originally Posted by blazer94

Thanks everyone for your input, I had a feeling that it would be the case to go back to the 195 T-stat. I replaced the heater core and radiator back in 10/94, and when i did the motor I put in new water pump w/ 180 t-stat. Changing back to ac-delco 195 this afternoon. Thanks again everyone.

Thought I'd tell why I put 180 deg. in the first place. On a sunday, when I changed the water pump (ac/delco), I'd forgotten to get a t-stat. Went to Murrays (they sell ac/delco parts) to get replacement, had to be ordered. In stock was prestone 180, so I figured , eh, I'll run a little cooler, and idiot that I am, and knowing in the back of my mind that 15 deg. does make a difference, (and figuring it was winter, shouldn't make a difference) went ahead and used it. Moral of the story: never take a fools ( my own ) advice without consulting others!

i put a "JET PERFORMANCE 180 TYPE" t-stat in my 01 4.3l, and it works fine, but i must justify. i eliminated the hp sucking drag monster of a fan/clutch driven off water pump for a "will not be FLEX able about endorcing products" dual fan with thermostatic controls. this way, living in the capital of south america, miami, i can run 3-5 deg less and get the ponies back without fan/clutch drag. i can adjust it to keep in the same temp band when the winter, way down to 40's, hits, and i can find my manual on heater operations.
just my 2 cents.

[blazee]

Check the dates before posting. This thread is nearly a year old.