I live in AZ, where the ambient temperature is well over 100 degrees. Well, I was doing a flush and bleed to my coolent system and for some reason the thermastat didn't seem to want to go back in the car , so I just left it out and have been driving without one for a month or so now. All my friends were like but its summer in arizona, and before I start the car the engine is already 110! That's the coolest a block of metal is going to get chillin in the shade around here so I was like, well, I'll make sure I'll figure it out before winter, but right now no sweat right? right?

Rufus

I have drivin my GT without one for a while and had no problems. Its whats called a continuous loop basicley what happens is your engine is constantley getting cooled and might not hit its proper operating temp. This will effect your MPG and cause your engine to run more rich. I live by the saying its there for a reason. try cleaning out your thermostat neck sometimes it gets a little grime in there that will make putting it back in a pain in the neck. Than force it down a little with the cap.

I just tried it agian, and it went right back in, don't know what the problem was the first time. Thx

Rufus

Try a 180 degree thermostat. A lot of guys use them and they don't seem to bother the ECM. That will lower the engine bay heat alot. I have been using one for a long time.

Good luck with it

Arn

The stock Fiero ECM likes to see 195 water temperature for the car to run properly. In the old days prior to computer run cars, I'd run without a thermostat until winter. The thermostats do fit only one way and can be "tricky" to get them to sit right, in my experience.

Operating without a thermostat can cause the engine coolant not to reach temperatures that would put the ECM into closed loop. If this happens your engine will run way rich and your gas mileage will go down. While the 2.8L was designed for a 195*F thermostat it will go into closed loop with a 180*F unit. My turbo and supercharged Fieros both use them. I've done considerable scanning and everything looks good but they are primarily summer vehicles. In the dead of winter you won't have an effective heater with a 180*F thermostat so buy one and try it. In Winter you can always pop the 195* unit in as it only takes minutes to change them.

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quote Originally posted by pontiackid86: I have drivin my GT without one for a while and had no problems. Its whats called a continuous loop basicley what happens is your engine is constantley getting cooled and might not hit its proper operating temp. This will effect your MPG and cause your engine to run more rich. I live by the saying its there for a reason. try cleaning out your thermostat neck sometimes it gets a little grime in there that will make putting it back in a pain in the neck. Than force it down a little with the cap.

I agree shouldnt be a problem,because you live in a hot enviroment I would definatley leave it out.Other things you can do is buy a low temperature fan switch from Rodney Dickman allso you can add a manual fan switch, for those hot days.Leave a post,if you want to try that.Your fan will turn on and off normalley with the engine temperature,but with the aid of the manual fan switch,you can turn on the fan and leave it on for those hot days.If you have smog tests in your state turn the switch off and reinstall your thirmistat,so your car will get out of closed loop.

my old red GT had a perfectly functional heater even in harsh new england winters with a 180° stat and a 195/185 fan switch. the heat output was comparable to my black GT that had a 195° stat and a 210/210 fan switch.

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quote Originally posted by Dennis LaGrua: Operating without a thermostat can cause the engine coolant not to reach temperatures that would put the ECM into closed loop. If this happens your engine will run way rich and your gas mileage will go down.

Just so we're clear... that would be open loop, not closed. No O2 sensor feedback for fuel trims.

On another note... the thermostat sets the low operating temp in the motor, if you are overheating due to some other reason, (plugged radiator, crushed pipes, etc...) you can still overheat without any thermostat at all.

[This message has been edited by carbon (edited 08-11-2009).]

My cold weather heater works fine with the 180* and it even worked with the 160*, however, 160* is good for a track but not so good for fuel economy.

180* thermostats are common place with all 60degreev6's.

Arn

You need the thermostat no matter what the temp to 'restrict' water flow enough to make it circulate thru all the passages. Not running one and water will go the path of least resistance bypassing flow completely in some passages resulting in hot spots in the heads and block and can cause permanent damage.

My turboed Fiero would not run on any thermostat warmer than 160*. I drove it as a year round driver in Ohio and never had a problem in 7 years with heat or defrost even in 0* weather, in fact it warmed up pretty quickly.

My V8 SBC Fieros also ran 160* stats all year round. I also had 160* in both of my C4 Corvettes. Milage on those by gauge indicated 25-27 mpg highway.

quote Originally posted by rogergarrison: You need the thermostat no matter what the temp to 'restrict' water flow enough to make it circulate thru all the passages. Not running one and water will go the path of least resistance bypassing flow completely in some passages resulting in hot spots in the heads and block and can cause permanent damage. .

I agree.
Also since the water never stops in the radiator for the moving air and fan to cool it off (it just keep s flowing), it will likely get hotter.

quote Originally posted by carbon: Just so we're clear... that would be open loop, not closed. No O2 sensor feedback for fuel trims.

No, he said it right, you just read it wrong. Try it again, only slower.


Edit, to say, after reading your response again, I'm not sure if you are contradicting him, or slimplifying his answer....
The car would stay in open loop, until it reaches proper temp needed for the ECM to put it into closed loop is what he was saying. Sorry for the confusion.

Kevin

[This message has been edited by Lambo nut (edited 08-11-2009).]

quote Originally posted by Rufus88: Well, I was doing a flush and bleed to my coolent system and for some reason the thermastat didn't seem to want to go back in the car

You can make your thermostat much easier to insert if you grease the o-ring on it with a little faucet grease. It's normally used on the o-rings of washer-less faucets that most people have in their houses. You can get it at any hardware store.

quote Originally posted by James Bond 007: I agree shouldnt be a problem,because you live in a hot enviroment I would definatley leave it out.Other things you can do is buy a low temperature fan switch from Rodney Dickman allso you can add a manual fan switch, for those hot days.Leave a post,if you want to try that.Your fan will turn on and off normalley with the engine temperature,but with the aid of the manual fan switch,you can turn on the fan and leave it on for those hot days.If you have smog tests in your state turn the switch off and reinstall your thirmistat,so your car will get out of closed loop.

Will do!

Rufus

quote Originally posted by Dennis LaGrua: Operating without a thermostat can cause the engine coolant not to reach temperatures that would put the ECM into closed loop. If this happens your engine will run way rich and your gas mileage will go down. While the 2.8L was designed for a 195*F thermostat it will go into closed loop with a 180*F unit. My turbo and supercharged Fieros both use them. I've done considerable scanning and everything looks good but they are primarily summer vehicles. In the dead of winter you won't have an effective heater with a 180*F thermostat so buy one and try it. In Winter you can always pop the 195* unit in as it only takes minutes to change them.

Other than some sort of scanning tool is there any other physical way to determine if the car is in or out of closed loop operation??

quote Originally posted by Lambo nut: No, he said it right, you just read it wrong. Try it again, only slower. Edit, to say, after reading your response again, I'm not sure if you are contradicting him, or slimplifying his answer.... The car would stay in open loop, until it reaches proper temp needed for the ECM to put it into closed loop is what he was saying. Sorry for the confusion. Kevin

You sir, are correct, sir. Geez two F' ups in two different threads in one day... Sorry Dennis.

quote Originally posted by carbon: You sir, are correct, sir. Geez two F' ups in two different threads in one day... Sorry Dennis.

It's all good. I've had days like that too, trust me.

Kevin

Roger again hit the nail on the head. you can overheat the car running with no tstat. there is a designed restiction in all motors that is used to both slow the coolant velocity and cause proper flow. coolant flowing too fast is not going to transfer heat properly. if you insist on not running the tstat, at the very least remove the center part and run the outer disc. even that is not a sufficient flow, but it is better than no tstat.