Engine temps
Thread Starter
Burning Brakes
Joined: Nov 2016
Posts: 761
Likes: 79
From: Buchanan GA
Engine temps
1985 coupe. All stock car. Fan programmed to come on at 205 and off at 195.
Last year I had a water pump failure and went ahead and replaced the t-stat and radiator cap along with it. I ordered a 185 degree stat but was shipped a 160 degree stat. I didn't realize this until after I installed it and put the car back on the road. (Pulled it back out and saw 160 stamped on it.)
My question is how cold is too cold and why? My oil temp (according to the dash) runs about 15-20 degrees above coolant temp in the 185 to 200 range. Am I doing harm here? I still have all of my emissions hardware intact and functioning so I would assume my fuel trim is being regulated based on what the 02 sensor sees?
Last year I had a water pump failure and went ahead and replaced the t-stat and radiator cap along with it. I ordered a 185 degree stat but was shipped a 160 degree stat. I didn't realize this until after I installed it and put the car back on the road. (Pulled it back out and saw 160 stamped on it.)
My question is how cold is too cold and why? My oil temp (according to the dash) runs about 15-20 degrees above coolant temp in the 185 to 200 range. Am I doing harm here? I still have all of my emissions hardware intact and functioning so I would assume my fuel trim is being regulated based on what the 02 sensor sees?
Drifting
Joined: Apr 2014
Posts: 1,699
Likes: 231
From: Hawthorne CA
1985 coupe. All stock car. Fan programmed to come on at 205 and off at 195.
Last year I had a water pump failure and went ahead and replaced the t-stat and radiator cap along with it. I ordered a 185 degree stat but was shipped a 160 degree stat. I didn't realize this until after I installed it and put the car back on the road. (Pulled it back out and saw 160 stamped on it.)
My question is how cold is too cold and why? My oil temp (according to the dash) runs about 15-20 degrees above coolant temp in the 185 to 200 range. Am I doing harm here? I still have all of my emissions hardware intact and functioning so I would assume my fuel trim is being regulated based on what the 02 sensor sees?
Last year I had a water pump failure and went ahead and replaced the t-stat and radiator cap along with it. I ordered a 185 degree stat but was shipped a 160 degree stat. I didn't realize this until after I installed it and put the car back on the road. (Pulled it back out and saw 160 stamped on it.)
My question is how cold is too cold and why? My oil temp (according to the dash) runs about 15-20 degrees above coolant temp in the 185 to 200 range. Am I doing harm here? I still have all of my emissions hardware intact and functioning so I would assume my fuel trim is being regulated based on what the 02 sensor sees?
Hopefully some of these c4 encyclopedias will come around and give some good insight.
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,218
Likes: 1,174
From: Southlake, TX
You have opened a can of worms as everyone will have a different opinion what is "too hot or too cool."
Blasphemy yes, but if you want to be certain, put your cooling minimums to factory specs. GM paid a boat load of money to figure out what works. This is especially true if you are a "cruiser" with the occasional "spirited" driving.
So, I'd run the factory 195 thermostats or ever so slightly lower (180) and you will be good for minimums.
Blasphemy yes, but if you want to be certain, put your cooling minimums to factory specs. GM paid a boat load of money to figure out what works. This is especially true if you are a "cruiser" with the occasional "spirited" driving.
So, I'd run the factory 195 thermostats or ever so slightly lower (180) and you will be good for minimums.
Burning Brakes
Joined: Jan 2017
Posts: 961
Likes: 237
From: Diamondhead Mississippi
St. Jude Donor '17-'18-'19-'20-'21-'22
If the higher temps were done by the factory for emission control would the people living in states like California have a problem passing emission checks if running the low temp stat like the 160?
Team Owner
Joined: Jul 2004
Posts: 28,432
Likes: 3,285
From: Hartford WI
Define "works"? The question is what criteria needs to be satisfied before they stamp "it works". That way, you can tell what works for YOU and not necessarily what works for GM. According to GM, my car doesn't get "it works" because of their criteria. It works per MY definitions which reflect what I, not GM, I seek in the car. They have to meet EPA rules. I could care less.
Thread Starter
Burning Brakes
Joined: Nov 2016
Posts: 761
Likes: 79
From: Buchanan GA
Define "works"? The question is what criteria needs to be satisfied before they stamp "it works". That way, you can tell what works for YOU and not necessarily what works for GM. According to GM, my car doesn't get "it works" because of their criteria. It works per MY definitions which reflect what I, not GM, I seek in the car. They have to meet EPA rules. I could care less.
Thread Starter
Burning Brakes
Joined: Nov 2016
Posts: 761
Likes: 79
From: Buchanan GA
Technology has come a long way since 1985. Back in the day they needed all the help they could get to burn clean.
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Le Mans Master
Joined: Aug 2017
Posts: 6,940
Likes: 1,490
From: New Jersey
The only way you'd cause damage is if the piston and rings never get warm enough to clearance right. That being said it happens at a low enough temperature that even at 160 you'll be fine. Being honest I'd be surprised if you run lower than 170 when its warm outside.
Now if it were a newer vehicle where it won't command closed loop until a certain temperature then you'd have a problem. When the thermostat in my truck goes bad it'll run rich and dump excess fuel and kill the cat. I believe these don't require that temp or it is set really low. Again you'll be fine.
Now if it were a newer vehicle where it won't command closed loop until a certain temperature then you'd have a problem. When the thermostat in my truck goes bad it'll run rich and dump excess fuel and kill the cat. I believe these don't require that temp or it is set really low. Again you'll be fine.
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,218
Likes: 1,174
From: Southlake, TX
Aklin/Silver 85... You are both correct and both "proved" my comment about that everyone has a different opinion about hot or cold and the individual choice that are made.
If I understood the original question correctly it was about "causing harm or doing damage." Since GM had warranty issues to mitigate, I'd think it logical that the factory specs are (should be??) considered the "baseline" and that you make decisions on your tolerance for risk.
Frankly I don't think you are doing any damage running a 160 and the oils manufactured today are of much better lube quality.
If I understood the original question correctly it was about "causing harm or doing damage." Since GM had warranty issues to mitigate, I'd think it logical that the factory specs are (should be??) considered the "baseline" and that you make decisions on your tolerance for risk.
Frankly I don't think you are doing any damage running a 160 and the oils manufactured today are of much better lube quality.
Last edited by billschroeder5842; May 1, 2018 at 09:43 PM.
Team Owner
Joined: Dec 2007
Posts: 20,974
Likes: 261
If you drive in "cold" weather, leave it. It is sold as an off the line "sports"car for "consumers" so it has to be able to start run and function no different than a Chevy van it shares parts with. Driving in snow is at your own risk.
If you drive in "normal" weather, I would do the 160° and I do.
If you drive it like a sports car 160° is best.
HEAT = more wear in ALMOST every scenario.
If you drive in "normal" weather, I would do the 160° and I do.
If you drive it like a sports car 160° is best.
HEAT = more wear in ALMOST every scenario.
Team Owner
Joined: Jul 2004
Posts: 28,432
Likes: 3,285
From: Hartford WI
Team Owner
Joined: Jul 2004
Posts: 28,432
Likes: 3,285
From: Hartford WI
Le Mans Master
Joined: Aug 2017
Posts: 6,940
Likes: 1,490
From: New Jersey
The quality control over those I would speculate is significantly higher. And the understanding of how it all works together should be better too but does that really count... That being said, S.S.D.D.