86V6 auto, the car tends to run warm with a 195 that even has a little hole drilled in it so i removed it, now the car only warms up to about 1/8th on the gauge (just Peachy) i DO have some reason to belive that the threnostat MAY be bad, but havent relly checked into it i just removed it,
does it relly make a differance in gas mileage with out it? i think i only get about 120miles to a tank, the most i can ever put in is 8.2 gal. my tank is dented in a little so im loosing a little cap.

should i try a new stat. or possibly a 185*
i know that V6 auto's suck at MPG but i was just curious as to if running W/O a thermostat relly makes any noticable differance?

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Rich AIM: ONE FAST 2M8

white-- 86se V6 daily driver
Gold--- 86se 355 SBC

With out the thirmistat it will take longer to kick down because the moter will run cooler for longer periods of time.The moter should kick down at 160 degrees.

The fuel maps in the ECM are controlled by, among other factors, the temperature as reported by the coolant temperature sensor. The mixture will be richer the cooler the engine is, and this reduces gas mileage accordingly.

JazzMan

In hot weather the missing thermostat will not make it run cooler, the top end of the engine temp is controled by the fan sensor. The bottom end is set by the thermostat. The main differance with no thermostat will be that you will run richer than it should on cool days and it will take longer to reach the proper opperating temp all the time.

Yes, engine temps do affect MPG. Once the engine goes closed loop (around 116F CTS), it's down to the efficiency of the engine. The engine is substantially more efficent at 200F than it is at 160 or lower. Even at 230F, your nerves are at more risk than the engine.

250F is where the problems start to come in. You are getting close to the limit of the coolant to not boil. The engine can handle it but you're going to lose coolant very soon (around 265-ish).

There is no reason to run the engine under 180F and many reasons not to do it (mentioned ad nauseum). The fan temp switch is high for a reason. The efficiency is good and the engine can easily handle it.

If your cooling system is bad, then going to a lower temp stat is just a bandaid.

quote Originally posted by $Rich$: 86V6 auto, the car tends to run warm with a 195 that even has a little hole drilled in it so i removed it, now the car only warms up to about 1/8th on the gauge (just Peachy) i DO have some reason to belive that the threnostat MAY be bad, but havent relly checked into it i just removed it, does it relly make a differance in gas mileage with out it? i think i only get about 120miles to a tank, the most i can ever put in is 8.2 gal. my tank is dented in a little so im loosing a little cap. should i try a new stat. or possibly a 185* i know that V6 auto's suck at MPG but i was just curious as to if running W/O a thermostat relly makes any noticable differance?

not in your case. your already getting the crappy milage. you should be getting at least 150 miles, up to 180 miles per ~8 gallon fill-ups.

I take the past comments as questionable.Read (how big is my gas tank?) I have a thermastat in my GT,but there is no thermostat in the lime green coupe,because it was allways over heating and blowing antifreeze into the overflow tank.So we got a LOW temp. fan switch from Rodney and never did put in the low temp.thermostat.IF this all that bad to lower the temp.of the engine,why would Rodney be selling the low temp. stuff?

its not BAD to run a low temp thermostat, it just wrecks the milage. It raises the HP's. So, its not bad, its a trade-off - HP's for Milage.

Like TK said, I would not run any colder engine temps than 180. With a 160 stat or no stat the engine is going to run too cold, besides the fuel being rich many other factors start to come into play.

-Accellerated piston ring, piston, and cylinder wear due to engine oil not at operating temp and fuel mixture being too rich and washing down the cylinder walls

Keep in mind that many things in your engine depend on oil splash for lubrication. Couple this with the fact that your engine oil needs to be at a certain temp for it to work properly and burn off moisture and impurities. If you are not running a stat, or running too cold of a stat then chances are your engine is going to wear out much quicker. This fact was reinforced to me when a friend put a 160 stat in his LT1 camaro at the beginning of one season and by the end of the season the blowby (cylinder leakdown) was blowing his breather tube off and his dipstick out on WOT excursions.

Ultimately the choice is yours what you do with your engine but I have experience and training that says don't run anything colder than a 180. Again, this pertains to a durability concern and if you want that extra 5-10hp a 160 stat can offer and don't care if the engine wears out then by all means use it.

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power corrupts. absolute power corrupts absolutely.

Custom Chip Burning | Fiero Engine Conversions | Turbocharging | www.gmtuners.com

You said it bro. It make people feel better but does little for the engine.

I believe in 160* stats myself. My V8 Fiero GT, the Ferraro, and both vettes run fine on them even in winter. NOT running any at all will give your engine hot spots internally as the water will flow more freely in easy ports and tend to not circulate in the rest. It may hurt the gas mileage a little, but I regard that as an acceptable loss with my engines running a lot longer without wearing out.

I'm sure thermostats have an effect on fuel mileage....to what degree varies on the person you talk to. I bought my 87 from Wisconsin and drove it back here to Indiana in the middle of winter...it never warmed up. It had no stat (cold drive home) and after 4 hours of highway driving I was getting 26mpg at 80mph (V6 5spd Isuzu). It now has a 195 stat, warms up nicely, and highway mileage is still about 26mpg at 80mph.
So, for me it didn't seem to have an effect. It makes sense that it would burn more gas without one though....at least based on how the ECM works

Dave

well an update, i took my 195* one and boiled it tonight in a pan on the stove and it barley opened, too bad because it was only a year old, ah well, so i went and bought a 180* one tonight and boiled it right away ouof curiosity as to how far they opened and it worked as it should, so i installed it so well see how it works
thanks for all the advice as always ++'s to all

quote Originally posted by 87V6GT: I take the past comments as questionable.Read (how big is my gas tank?) I have a thermastat in my GT,but there is no thermostat in the lime green coupe,because it was allways over heating and blowing antifreeze into the overflow tank.So we got a LOW temp. fan switch from Rodney and never did put in the low temp.thermostat.IF this all that bad to lower the temp.of the engine,why would Rodney be selling the low temp. stuff?

Rodney sells them because people want to buy them.

JazzMan

hi, not to disagree i recently did a check with scanner and aftermarket gauge on my v6 se, the thermo is 160 and 176 fan switch, at @145 it goes into closed loop , the fan switch goes up to 181.2 and runs until 171.4, and i let it idle for 1/2 hour while i checked other things on car, i wanted to see how it would fiar, the fan came on at least 8 times in 1/2 hour and the temps stayed about the same, never went back to 160 after thermostat opened, the lowest was 171.4 like i said, i have to admit i have not ckecked milage yet, but as far a open/closed loop it stays closed,.....i will however, in several weeks check the plugs to see if i have carbon buildup, milage and horsepower fell about the same, until i can somehow scan it while driving, i wont be able to tell for sure............

ps stock chip, i have not decided if the hypertech thermomaster ($119)is worth it yet..........

[This message has been edited by silver86se (edited 06-03-2004).]