I have a 1999 Blazer 4.3 with a 195 thermostat with a small hole in it to try to keep it a tad cooler. Temp runs around 170-200 depends with traffic. Every other blazer i see with a stock 195 with a 4.3 engine temp is running around 145-150 or the first quarter mark. Im just wondering if theres something possibly wrong. My truck does seem to run a tad cooler in my opinion and ive always put a lower thermostat in all my cars and trucks but when i ordered my 180 I got sent a 195 and I had to work with it.

 

During the Oklahoma days of near 100 degrees I run about 190 give or take a few degrees. At night it runs solid at 165ish.

 

[quote=PaulO2288;230690]I have a 1999 Blazer 4.3 with a 195 thermostat with a small hole in it to try to keep it a tad cooler...quote]
How's that supposed to work?

 

my 91,im running 150 on a hot day,well at least thats what the gauge says..its got a 180 thermo in it.

 

Mine runs just under 210 at about 200. These engines need to see 200 degrees or the computer will not function properly. Your gas mileage will be in the hole and your cat will get clogged as well as others problems.

 

Hmmm thats weird, Usually almost every blazer ive ever seen has been in around 140-160

 

That's not hot enough for the computer to run the engine properly... you will get terrible gas mileage and there is no way it would ever pass an emission test. (not that alot of us have to worry about that)

 

Bandido what are your sources? I'm interested in learning more.

 

It keeps the engine in 'open loop' mode which is a condition found when the engine is cold (like at start-up) during which the computer, via its feed-back sensors, keeps the air/fuel mixture richer to aid cold engine driveability.

 

True 150 degrees, both gauge and independent thermometer...even on 100 degree days in Florida....

But Bandido is correct, your mileage will suffer and you cat will get clogged, and also my oxygen sensors got all crudded up too...