i thought it was my car overheating lately and i do some searching before i post up a new thread and i see its not just me..
my fans wont kick in till way past 220. my question is should i get the 220* and stay with the 195 thermostat. or get the 180 fan switch and the 180 thermostat.

which is better for the car.????

please let me know i plan on ordering them asap .... also if i do change those two out is there a need to change the coolant temp sensor or not ..

im worried about the summer time and sitting in traffic. will 220 be suffice

87 gt v6 auto.

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new fiero owner...
1987 gt v6 blue

[This message has been edited by freedom0226 (edited 01-21-2010).]

I'd go with the 220 and keep the 195 stat.

The engine is tuned to run at 195 to get the best mileage.

My 2 cents.

[This message has been edited by Dodgerunner (edited 01-21-2010).]

I second what Dodgerunner said

X3 if you get a lower temp fan switch it could kill your gas milage. the 180* is for high heat areas such as arizona and places like that.

i just dont like the fact i think im over heating . always looking at the dame needle..

but let me ask you if the lower i go the worst the gas.. then i will keep 220 since im in new york. but why is it i get horrible gas mileage now ? maybe its just me or not but i just filled up my tank 3 days ago and im already at half tank. i dont use the car that much just to work and back home. and i work in the same borough .

Keep in mind that the fan switch sets the maximum coolant temperature, and the thermostat sets the minimum. So a low-temp fan switch won't necessarily make the engine run too cool. Because the thermostat will close to maintain a certain minimum temperature.

That said, I used to have Rodney Dickman's 195°F fan switch, with a stock (195°F) thermostat. IMO, this is ideal, because the fan kicks on as soon as the thermostat is fully open. It worked very well for me.

So right about now, you're probably wondering why I said "used to". That's because I installed a GM 1227730 ECM, which controls the radiator fan (no fan switch). And coincidentally, I had the ECM programmed to kick on the fan at 195°.

quote Originally posted by freedom0226: but why is it i get horrible gas mileage now ? maybe its just me or not but i just filled up my tank 3 days ago and im already at half tank. i dont use the car that much just to work and back home. and i work in the same borough .

The Fiero gas tank is fairly small at 10-11 gal. Guess the average mpg for the 2.8 is around 25-30 on the highway and in NY traffic could be as low as 12-15... Do the math from there...

Keep in mind the Fiero gas gauge is 22+yro and is not the most accurate device to begin with... Best way to figure your MPG is to fill your tank, reset your trip, then refill you tank after a few days. Take your tip odo millege and devide it by the number of gallons you put in to get your MPG...

Telling us you tank is at half after 3 days does not mean much...

quote Originally posted by freedom0226: i just dont like the fact i think im over heating . always looking at the dame needle.. but let me ask you if the lower i go the worst the gas.. then i will keep 220 since im in new york. but why is it i get horrible gas mileage now ? maybe its just me or not but i just filled up my tank 3 days ago and im already at half tank. i dont use the car that much just to work and back home. and i work in the same borough .

Is yours an 86? also what tranny do you have? If its an auto or the 4 speed this may explaine your MPG. Auto sucks either way but the 4 speed will Suck up gas at highway speeds.

With the colder winter temperatures it's normal to get less MPG. I run the stock temperature thermostat and fan switch here on the South Texas border with no overheating problems.

Mike

Sorry, but I have to disagree with the notion that a 180* setup is undesirable.

I run a 180* thermostat with a 195* switch. It runs great and gets good gas mileage. It runs cooler. I have the Y pipe wrapped with header tape and that helps too.

If you know anything about running a car in cold weather, you know that it takes a long time to get up to full operating temperature. In fact, the car can go for days on end and never reach it. All the while still getting good gas mileage. Practically speaking I can tell you that there is no difference in gas mileage between the 180* and 195* thermostat except in really hot weather when the 180* clearly outperforms the 195*.

The ECM will operate perfectly in a range of temperatures, both above and below boiling point. I have had my engine on a 160* thermostat and it ran ok but took a longer time to warm up so I went back to the 180*.

If you assume the car has to be running at 215* to get good gas mileage, then you must also believe that if the engine is at 210* it is suffering poor gas mileage. It does not compute. The engineers designed it to operate within a range of temperatures. It does exactly that. I will concede though, that the 160* thermostat, while great for producing power at the track, will not produce as clean a burn and therefore should not give as good gas mileage.

Hope this helps.

Arn

I went with the 220 and my 2.8 5sp ran cool all summer...including in the first time ever over 100 degrees in Seattle. Even in traffic it did fine.

An interesting note: I have an outside temp indicator. The sensor is mounted at the bottom of the front bumper on my coupe, just behind the bottom flexible piece ( I do not know what you call it). Anyway, you can really see the temp climb when you are at a stop and idling.
Jim

I have both setups and have used both in the same car. Rodney's setup definitely helped my car run lower temps. I was getting 225 deg in summer traffic and occasionally got the "temp" lite on.

Rodney's setup held at a solid 180-195 deg, regardless of the weather.

I did notice a slight reduction in gas mileage, but this was about the same time my motor was going out, so I can't attribute the lower mileage to the thermostat with absolute certainty. I did not notice any other issues.

I currently have the stock sensor and t-stat in my 3.4 PR. It's running at a solid 180 deg, but its winter. I'll leave it in until the weather gets hot and see what develops.

I ran 160* stats and 180* fan switches in my turbo Fiero, V8 Fiero and both of my vettes. I never had an overheating problem, never had a winter heating problem. Losing a mile or 2 per gallon was not a big deal for the extra worry factor. My New Yorker and Coronet are also running 160*.

the stock design will obviously work fine. plenty out there using it even now, 25 years later.

180-185 is the magic number for closed loop mode

and, I also dont want my fan running basicly non-stop
lucky for me, I use a 7730 ECM, with which the fan setting is ECM controlled - so I have a 190 fan switch with a 180 thermostat

i love it . thanx for the advice im going to stick with the stock 195 thermostat and buy rodneys 210/200 degree: $19.00

this should be ideal for me since im in new york where you never know how the weather will be. yesterday was hot today is cold and windy....

so ive read a bit on this and i shouldnt have to flush out radiator fluid as long as i do this while the engine is cold and i lift the car from the back right ?????? throw some teflon on the threads in stick it in. should be that simple..

correct me if wrong...

quote Originally posted by freedom0226: i love it . thanx for the advice im going to stick with the stock 195 thermostat and buy rodneys 210/200 degree: $19.00 this should be ideal for me since im in new york where you never know how the weather will be. yesterday was hot today is cold and windy.... so ive read a bit on this and i shouldnt have to flush out radiator fluid as long as i do this while the engine is cold and i lift the car from the back right ?????? throw some teflon on the threads in stick it in. should be that simple.. correct me if wrong...

wont have to flush out - but if you want to prevent any spillage, drain a 1/2 gallon of coolant.
the fan switch is pretty high in the coolant system, but not higher than the thermostat neck, so when you remove the switch, all the coolant at a higher level will pour out the hole.
and, teflon tape is not always recommended - the reason is - the switch is a ground switch. if the switch does not make good contact to ground - it wont work. but, normally - threads do cut thru the teflon tape and do end up making contact. so - if you use it - be light, and keep it high on the threads

For YEARS, I ran a 180 thermostat and a 180 temp fan switch.

Honestly, the 180 degree thermostat was a good upgrade. The car is tuned to work at 195, but I really felt that teh 180 degree thermostat was so minor of a change that it really had a very little effect on the car. For one, I noticed no change in fuel economy, but I did notice that the car felt smoother all the time. It never got "sluggish" like it used to do on really hot days.

But as far as the low temperature fan switch, that was a waste. With the low temp fan switch, the fan basically ran within 7-8 minutes of starting the car, and then ran forever... which was pretty unnecessary. Unless you live somewhere that it gets over 100 degrees ambient temperature on a regular basis...

------------------
Todd,
2008 Jeep Patriot Limited 4x2
2002 Ford Explorer Sport 2dr 4x2
2002 Ford Crown Victoria LX
1987 Pontiac Fiero SE / V6
1973 Volkswagen Type-2 Transporter

First of all the gages are not that accurate. Secondly the cooling fan does not kick on until about 234 degrees as it was designed like that and is not running hot. It runs until it at least gets it down to 210 to 215. The thermostat may open on the stock setting of 195 but this is how it was designed to work and be most efficient. My 2000 Bonneville runs constantly at 210 on the gage when it is up to operating temp. and it has a 195 thermostat. Works pretty much the same way. The hotter an engine can run in a safe manner the more efficient it becomes. There was a lot of interest years ago in ceramic engines for that reason but they were not practical to produce and maintain.

I put in a Dickman 185 or whatever stat and fan switch and all I saw was poor gas mileage. I'm not knocking Rodney in anyway. He is providing a product that performs for what it is advertised to do but in my opinion GM engineers designed the engine and electronics to perform this way for a reason.

So the engine bay gets warm because it is in the rear and not the front. Big deal. Make sure everything in the cooling system is functioning properly, ie. no crushed lines, bad stats, air bubbles or inoperative fans and it will be fine. Too many people here do not understand the design and functionality of the setup and waste time, money and gas.

[This message has been edited by Mike Murphy (edited 01-22-2010).]

quote Originally posted by 82-T/A [At Work]: But as far as the low temperature fan switch, that was a waste. With the low temp fan switch, the fan basically ran within 7-8 minutes of starting the car, and then ran forever... which was pretty unnecessary. Unless you live somewhere that it gets over 100 degrees ambient temperature on a regular basis...

My experience exactly. Even on a 30-degree day, my fan would come on after just a few minutes and never shut off.

Don't forget that if you are experiencing overheating problems on a stock engine and stock parts, then you probably have a problem with your coolant system. The problem could be a fault rad. cap or crushed pipes, or bad rad. or.... You may want to check the simple things first.

J.

The thermostat sets the minimum temperature not the max. You can stick a 160 in there and still run well above that. You will get larger temperature swings (high load, temps go up, load goes down, temps drop back down.) I just don't think the thermal swings are worth it. The Fiero engine laughs at even 230 (as long as everything is working right).

If a 195 stat is used, why does the coolant get up to 220+ under normal conditions (high ambient and engine load)? Same thing for the 160. The temps will still rise under load when the air flow over the radiator is reduced. It won't keep the engine at 160 under all normal operating conditions it will just let the coolant go back down to around 160 if the engine load is reduced.

At best, a 160 buys you time but doesn't solve any problems unless you just need the extra 3 minutes before you overheat. A wide open 160 stat flows the same amount as a wide open 195. And since your coolant probably isn't at 160 in the first place, you bought yourself even less time.

I would run a 205 stat if I could find one but for now I run a 195 and the 210 switch from Rodney since we get to 110F here and I am often in slow traffic. Above about 30 MPH the fan is irrelevant and you are now cooling the radiator pretty much with just air flow. The fan air speed is slower than the forward motion air flow at that point. That's why GM shuts off the fans on the later cars above about 30 MPH. They just aren't helping anything,

[This message has been edited by TK (edited 01-22-2010).]

TK I don't understand your logic.

The Thermostat is a bi-metal piece that is meant to expand as it is heated. When it reaches a particular temperature (highest) it flexes open. The thermostat allegedly controls the maximum temperature before the coolant is allowed to flow.

The fan switch is designed to turn on also when the temperature reaches or surpasses the critical temperature for it to switch on.

For this reason you generally have a thermostat that is about 15* lower than the fan switch. This allows for an interim before the fan comes on, and allows it to shut off before the thermostat goes to closed position.

This is the reason that if you put in a 180* thermostat with a 180* switch, your fan will appear to run all the time.

While the Fiero engine will run at 230* because it has to do so in a confined engine bay, it does not mean it is good for it. The Fiero's many plastic vacuum lines suffer with heat. The sensors like the MAP and EGR also suffer from heat. The plastic goes brittle after a time. This is the reason most car manufacturers spend so much on ventilation except of course, the Fiero which has poor engine bay ventilation. The engine oil and therefore the engine will give longer operational life with more moderate temperatures in the engine bay. The 180* thermostat is a very good thing for an older and somewhat tired engine with alot of plastic and vinyl on it.

If you have a 215* fan switch, the fan has to pick up the slack when the temps go over 215*. This means they can certainly hit 230 in a street application. For those of us who have auxilliary cooling, you notice a huge difference. In the summer I can pull into a drive through and my fans will kick on when the car idles, but, they don't stay on. They generally switch back off in about a minute. The reason being that I have the rad fan and a cowl fan. If I didn't have the cowl fan, the rad would stay on quite a bit longer, granted, however, with a 215* switch, it would switch off at 214*. Still leaving the bay hot. Mine swithes off at 194*. Big difference. so in the drive through, my engine never hits 215*. Hope this helps clarify.

Arn

Heres the pic,you need (wait to load).

None of my fans ever ran at all except on a 90*+ summer day in traffic. Never ran on the freeway at all.

quote Originally posted by Arns85GT: TK I don't understand your logic. The Thermostat is a bi-metal piece that is meant to expand as it is heated. When it reaches a particular temperature (highest) it flexes open. The thermostat allegedly controls the maximum temperature before the coolant is allowed to flow. The fan switch is designed to turn on also when the temperature reaches or surpasses the critical temperature for it to switch on. For this reason you generally have a thermostat that is about 15* lower than the fan switch. This allows for an interim before the fan comes on, and allows it to shut off before the thermostat goes to closed position. This is the reason that if you put in a 180* thermostat with a 180* switch, your fan will appear to run all the time. While the Fiero engine will run at 230* because it has to do so in a confined engine bay, it does not mean it is good for it. The Fiero's many plastic vacuum lines suffer with heat. The sensors like the MAP and EGR also suffer from heat. The plastic goes brittle after a time. This is the reason most car manufacturers spend so much on ventilation except of course, the Fiero which has poor engine bay ventilation. The engine oil and therefore the engine will give longer operational life with more moderate temperatures in the engine bay. The 180* thermostat is a very good thing for an older and somewhat tired engine with alot of plastic and vinyl on it. If you have a 215* fan switch, the fan has to pick up the slack when the temps go over 215*. This means they can certainly hit 230 in a street application. For those of us who have auxilliary cooling, you notice a huge difference. In the summer I can pull into a drive through and my fans will kick on when the car idles, but, they don't stay on. They generally switch back off in about a minute. The reason being that I have the rad fan and a cowl fan. If I didn't have the cowl fan, the rad would stay on quite a bit longer, granted, however, with a 215* switch, it would switch off at 214*. Still leaving the bay hot. Mine swithes off at 194*. Big difference. so in the drive through, my engine never hits 215*. Hope this helps clarify. Arn

From a durability standpoint, 230F is nothing. It's the coolant itself that doesn't work above about 265. And while the coolant might be at 160 the surface metal certainly isn't, so any impact on the plastics isn't reduced by any valuable amount with a 160 stat. There is exploding gas in there and the heads and manifolds aren't going to get down to 160.

Any significant forward motion in the Fiero generates enough air flow through the radiator to shed enough heat to pull the coolant temps down. If you are stopped, you bet, the fan has to do to the work especially since you can get some recirculation back to front but once we are moving much above 30 the fan is moving less air than the air pressure at the front and it's not really doing anything. Now if you are stopped AND the fan never comes on, you will be heading for 260 in short order.

The only issue with 230F is that you are within 35 degrees of the coolant boiling point which is the bad part, so running a lower temp switch is good when we aren't moving or going too slow for air to flow through the radiator. So I run a 195 and the 210 (or is it 215) switch. If I am stopped, the fan will come on and pull it down to the lower limit (210-ish). With the 195 stat I only saw 230+ with the stock switch but that was only when I was stopped or in slow traffic. The 215 switch just comes on earlier.

But I just don't worry about hitting 230 and neither did GM. I don't see any value to a 160 stat. The engine just won't run that low all of the time (maybe in really cold areas). And I still don't believe 230 coolant is going to take any major toll on the plastics. Age will do that long before the temps will.

But, if people want to run 160 stats have at it. It's not impending doom, it just doesn't do what people think it does. You just get a bunch of temp cycling which doesn't help anything. Lowing the fan on temp is fine but if you are cruising down the road at 65 MPH, it's not really doing anything. You might as well just shut if off. At a stop, yes, it makes it come on earlier and keeps you farther away from the ugly 265 coolant boiling temp.

Don't get me wrong, if I was running down the road at 65 MPH on a 110F day and seeing 230 (on the sacnner, the gauge is useless), something is seriously wrong and I wouldn't keep driving. I prefer to keep the operating temps under 205 so I have some room to the coolant boiling point. I have never seen this happen. The highest I've seen is 220 on a 110F day climbing an 8% grade for 8 miles. Obviously both the 195 and 160 stats would be wide open but the electric fan wasn't doing squat to help.

This is all based on the scanner data and a probe in the engine stat housing.

TK

[This message has been edited by TK (edited 01-22-2010).]

What happens if the ecm coolant temp switch is faulty? What if the ECM never goes into closed loop? WIll the ECM sense that the engine is cold and add more fuel? Would that greatly affect the fuel economy?

Has anyone ever compared the temperature in the engine compartment sitting still after the engine has reached the full capacity cycle of the cooling system between a stock setup and one modified with a lower fan switch and stat with an infra red temp scanner?

I bet there is no difference especially after driving for a few miles. It just plain gets hot in there regardless with the exhaust manifolds, catalytic converter and muffler. There is no ambient airflow like you get from the front of the car when it is moving.

Probably not 10 degrees difference if the cooling system on both cars is working to full capacity.

[This message has been edited by Mike Murphy (edited 01-22-2010).]

There can be a big difference Mike. My engine bay is way cooler since modding it. The only time it gets above 195* to kick on the fans is when I've been running, and the car comes to a standstill and it is hot out. Under way, and the fans just don't come on.

This is a far cry from a stocker with just the rad fan. The heat build up gets extreme. Whereas my pipes are wrapped and a lower potential temp, the stock engine can get up well over 230* in the compartment. The difference is pretty noticable once you've driven a Fiero with a modded cooling system.

Arn

The best temperature for the engine to run is between 200-220*. (it's actually a little higher ~250ish,but engine oil breakdown and other things make it unattainable)
Just reread that in smokey yunick's book-and I believe anything he says almost.
This isn't taking into account best intake temperature,engine bay heat detrimental effects etc..,only engine running temperature.

i got more than what i needed as far as advice with this thread.. im sticking with my 195 stat and already ordered the 200 210 fan switch from rodney. i am not mech savy at all and finally just found that damn fan switch so hidden. im waiting till it comes in and im going to do it myself...i want to thank you all for the advice...
i wont attempt the distributor cap and rotor myself im going to get my tune up done maybe by fiero jon in jersey...

but once again thank you all......its been 2 weeks with this car and i dont regret a thing......code 32 and all..

quote Originally posted by freedom0226: im sticking with my 195 stat and already ordered the 200 210 fan switch from rodney.

Good choice.

quote Originally posted by Blacktree: ... the fan switch sets the maximum coolant temperature, and the thermostat sets the minimum.

quote Originally posted by TK: The thermostat sets the minimum temperature not the max.

That is the right answer. If your street-driven Fiero is overheating there is something wrong, and a lower temperature thermostat won't fix it. At 230+ F, any thermostat you install (whether 160, 180, 195, or whatever) will have long since been fully open if it is working correctly.

quote Originally posted by Arns85GT: While the Fiero engine will run at 230* because it has to do so in a confined engine bay, it does not mean it is good for it. The Fiero's many plastic vacuum lines suffer with heat. The sensors like the MAP and EGR also suffer from heat. The plastic goes brittle after a time. This is the reason most car manufacturers spend so much on ventilation except of course, the Fiero which has poor engine bay ventilation. The engine oil and therefore the engine will give longer operational life with more moderate temperatures in the engine bay. The 180* thermostat is a very good thing for an older and somewhat tired engine with alot of plastic and vinyl on it.

I agree that lowering the engine compartment temperature in a Fiero is desirable, for the reasons you state. But I disagree that the thermostat you choose, and thus the cooling system temperature, will have any significant effect on engine compartment temperature. Radiation and convection from the exhaust system (manifolds, crossover pipe, downpipe, and catalytic converter) are by far the biggest sources of heat in the engine compartment.

[This message has been edited by Marvin McInnis (edited 01-23-2010).]

Where is everyone getting the info that Rodney sells a 220* fan switch? His two options are 195*on/185*off and a 210*on/200*off. The 195/185 is used with a lower temp 180* Thermostat and the 210/200 is used with the stock 195* thermostat. Other combos may be less effective.

The more heat (energy) that gets pumped out through the radiator = more gas (energy) used to drive over a given distance.

People keep mentioning the ECM looking at the coolant temp,just making sure this is in relation to fan speed.

Most people don't realize that the ECM doesn't use coolant temp to regulate engine running/fueling etc..
It uses cylinder head temp in most vehicles,which is NOT what your seeing on the guage.
The coolant temp is flaky at best and does not show true temp.

I noticed someone mentioned looking on a scanner,that is the right way to check engine running temps.

This is true on the OBDII vehicles I work on,not sure if the fiero uses separate sensors or not. Some vehicles only use a head temp sensor and some use a coolant temp sensor.
Most newer vehicles use both in my experience.
Hope this provides insight to some that didn't know this.

quote Originally posted by DefEddie: ... the [Fiero] ECM doesn't use coolant temp to regulate engine running/fueling etc.. It uses cylinder head temp ...

That is just plain false! Coolant temperature is one of several parameters (along with intake temperature, throttle position, absolute manifold pressure, and RPM) that is used by the Fiero ECM to control fuel delivery and spark timing. Cylinder head temperature isn't even available.

[This message has been edited by Marvin McInnis (edited 01-28-2010).]

Ive always believed in running cooler = longevity. Nothing was wrong or 'hidden problems' with any of mine. Most of mine got brand new, race shop built engines. 160* worked fine for all of them. We also used one in the race car for years. I never had an engine problem and no hint of one ever overheating. My turbo Fiero ran flawlessly for the 7 years I drove it like that. The Mercedes ran for 11 years the same way. I could idle a car for hours in 90+ temps. So what if I got 16 mpg instead of 18.....so I spent 25 cents more per day. The only cars I keep stock thermostat in are brand new ones under warranty so they wont have an 'out' on a claim. Even the new Magnum I got a tuner for recommended installing a 160-180 stat for best performance.

[This message has been edited by rogergarrison (edited 01-28-2010).]

quote Originally posted by Marvin McInnis: That is just plain false! Coolant temperature is one of several parameters (along with intake temperature, throttle position, absolute manifold pressure, and RPM) that is used by the Fiero ECM to control fuel delivery and spark timing. Cylinder head temperature isn't even available.

I'm sorry,I didn't specifically write fiero for a reason-didn't realize I didn't state clearly enough that this isn't true for all ecm's.

"This is true on the OBDII vehicles I work on,not sure if the fiero uses separate sensors or not. Some vehicles only use a head temp sensor and some use a coolant temp sensor.
Most newer vehicles use both in my experience."

I'll add that cylinder head temp is the most accurate way to determine engine temperature for the basis of calculating fueling.
This is the reason that on vehicles WITH a CHT that is what the computer uses for fueling and coolant temp is simply used for guage,light and fans. It is not the best indicator of engine running temperature.

If my 3.1 mclaren has only coolant temp I might figure out a way to add a cylinder temp for the ecm and just use the coolant temp for other stuff.
Anybody added one before? should be pretty easy to split the circuit,or if nothing else build a new circuit for the fans,light and guage.

[This message has been edited by DefEddie (edited 01-28-2010).]