As well all know the stock fiero fan switch turns on at way to high a temp. 238* and off at 220*

Well after some (not that much) looking I have a great soultion. The new fan switch is an off the shelf part. It turns on at 220 and off at 204. The P/N is TS136

Unlike a true low temp switch you can use this with a stock thermostat, and is probably what the car should have been spec'd with from the factory.

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3.4L 87GT

Were did you get it at, pontiac, napa were and how much did you spend on it.

Bare in mind that this will cause the fan to operate more frequently, alternator will work harder to put out the amps for the fan, engine will take longer to reach closed loop causing longer high idle at start up, as well as poor fuel effeicency as the computer will see the lower temp and will constantly be dumping gas in the mixture ( hence the high idle ) in a futile attempt to raise the temperature to see closed loop....

Few of many thing to keep in mind when running a low temp switch

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( the above was the thoughts, views, and opinions of a disgruntled Fiero mechanic, and do not express or
imply those of West Coast Fiero, Fieros West, or any other organization - just that of this poor
bastard ) :)

Eric Nelson
Technician,
West Coast Fiero
310-305-4111

West Coast..

Why? The engine will still be running at 190 degrees with a stock thermostat.

It seems that with the stock fan temp. switch, the engine and the entire cooling system (including radiator) has to "overheat" before the radiator fan even comes on.

GM could have taken a lesson from other car manufacturers who use the temp of the coolant at the radiator outlet to control the cooling fan. They turn on the cooling fan, when there is insufficient airflow through the radiator.

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fierosound - 1987 GT - World of Wheels Winner
& Multiple IASCA Stereo Award Winner (click me)

quote Originally posted by West Coast Fiero: Bare in mind that this will cause the fan to operate more frequently, alternator will work harder to put out the amps for the fan, engine will take longer to reach closed loop causing longer high idle at start up, as well as poor fuel effeicency as the computer will see the lower temp and will constantly be dumping gas in the mixture ( hence the high idle ) in a futile attempt to raise the temperature to see closed loop.... Few of many thing to keep in mind when running a low temp switch

Huh? I'm one of the biggest advocates of never using anything less than a 195 'stat...but I'm failing to see where turning on the fan at 220* instead of ~235* is going to cause the end of the world as we know it...

Misread the fan on temp, maybe? <shrug>...

Neal---good find, IMHO...

Take care all---
Jeremy B.

I am going to stay out of the above issue except to say that millions of GM cars are running prefectly with the fan switches at factory engineered settings.

On a separate note 235 degrees is NOT overheating, also the fan primarily is only there for air movement at low vehicle speed, air velocity is more than fan movement when you are driving down the road. GM set the ON temp high to keep the fan off unless it was absolutly necessary to turn it on. Running it more often will just wear it out sooner and create a bigger draw on the alternator.

I stated the facts, put it in and drive

- I dont care to add to a thread that is beginning to dawn into a flame fest

Hey Neal what Auto Parts store did you get that at and who is the manufacturer of the part?Is there a name on the box?....Thanks

quote Originally posted by West Coast Fiero: Bare in mind that this will cause the fan to operate more frequently, alternator will work harder to put out the amps for the fan, engine will take longer to reach closed loop causing longer high idle at start up, as well as poor fuel effeicency as the computer will see the lower temp and will constantly be dumping gas in the mixture ( hence the high idle ) in a futile attempt to raise the temperature to see closed loop.... Few of many thing to keep in mind when running a low temp switch

WOW, WCF never expected that one coming.

A, the alternator will work no harder... it will just have to turn the fan on more often. whichn is well within its design limits

and B, How will the engine take longer to reach closed loop. the fan wont turn on till 220, and if the motor isnt in closed loop by 220 then something is wrong. Also while crusing the motor should be running cooler than 220, thus the fan wont turn on unless stopped. and there will be no unnecessary added fuel.

All im going to say is that this is an off the shelf part for another GM vehicle, i never asked my parts guy to cross reference it whith what kind of vehicle, but it is a stock replacement part.

I'm not going to get involved in the for/against debate, but *if* you need the lower temp fan switch, it's made for the Buick Grand National/Regal Turbo. Just ask for an '88 Regal with the turbo. Most catalogs don't actually list the GN.

The main push behind lower-temp fan switches is supposed to increase horsepower, as the engine runs cooler... blah blah...lower intake temps, I guess... Anyway, I just supply the gun, I don't shoot people. =D

Regards,

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Kris Duck

Little, Yellow, Different

I was cruising Rodney's Site. (Need the stainless Cat), and saw that he has a 200-210 degree switch that allows you to keep the 195 degree OEM stat. It's only $19.00.

Would that be a good option?

I put Rodneys 160* stat and 175* switch in when I put my car all together. Its still working perfectly working on its second 100K trouble free miles. The ONLY problems ive had in all that time are ignition related. I may have lost 1 mpg economy but I can live with that

On a side note, my vettes fan switch is set @ 227* (factory) I put a 160* stat in it. Fan only comes on in heavy traffic. It has a MPG digital readout and changing the stat had absolutely no effect, still gets 27-29mpg on highway.

[This message has been edited by rogergarrison (edited 04-16-2003).]

quote Originally posted by West Coast Fiero: Bare in mind that this will cause the fan to operate more frequently, alternator will work harder to put out the amps for the fan, engine will take longer to reach closed loop causing longer high idle at start up, as well as poor fuel effeicency as the computer will see the lower temp and will constantly be dumping gas in the mixture ( hence the high idle ) in a futile attempt to raise the temperature to see closed loop.... Few of many thing to keep in mind when running a low temp switch

Sorry, but I think you're wrong on this one.

I've been running a 160 degree thermastat for over two years. I experiance no high idle problems and my gas milage ranges from 20 city to 24 hwy depending oh how heavy my right foot feels . I doubt seriously that changing the high temp fan switch will cause any negative effects. Of course I live in Florida so I've never had to test it in severe cold weather. However, the fan does run continuously when the A/C switch is "ON" so I'm sure the alternator is designed to handle the load. Again, I live in Florida so my A/C runs a LOT.

No flames, just my opinion based on my real-world experiences.

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Roy

double-click on this link to follow my interior build-up https://www.fiero.nl/forum/Forum2/HTML/031255.html
*** UPDATED 1/24/03 ***

Blue 87 GT w/ 4th generation Firebird interior.
Suncoast Fieros

I run an 180* thermostat and a 190* fan switch. It may be one of my pet quirks but I dislike running my engine with the coolant near the boiling point of water. When one runs a turbocharged engine as I do, excessive heat can trigger detonation. This does operate the fan more often but Fieros in the hot So. Western region will run with their fans on all the time anyway. As soon as that A/C buttom is pushed, the fan comes on. I believe that the cooling fans were designed for continuous operation.

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87GT 3.4 Turbo Best 0-60 5.2 seconds
http://turbofiero.fierojoe.com/turbo.htm

I think WCF may have a point if you're running a 160 thermostat, but if you're running a stock 195, then it should have zero effect on closed loop operation. The ECM should be in closed loop before 195*F. Any changes above that temp should have no effect. Now, running a 160 thermostat will cause changes in the closed loop operation, and will cause your car to take longer to warm up.

Sorry, Eric, I think you dropped the ball on this one. Your points are valid for low temp t-stats, but not if you keep the OEM t-stat.

I run a 195* thermostat, and a DR-137X rad fan switch. Turns on the fan pretty early, but of course doesn't effect the running temp other than never letting it swing up/down. Just allows a nice cool reserve of water to be sitting there waiting for it to be needed when the T-stat opens up.

Works fine!

quote Originally posted by Formula88: I think WCF may have a point if you're running a 160 thermostat, but if you're running a stock 195, then it should have zero effect on closed loop operation. The ECM should be in closed loop before 195*F. Any changes above that temp should have no effect. Now, running a 160 thermostat will cause changes in the closed loop operation, and will cause your car to take longer to warm up. Sorry, Eric, I think you dropped the ball on this one. Your points are valid for low temp t-stats, but not if you keep the OEM t-stat.

Although I have never tried it, I believe that tyhe ECM may enter closed loop operation at 160*.
If you do enter closed loop operation then the O2 sensor signal shoud monitor the mixture and keep it at 14.6:1 during cruise conditions. However, at WOT the mixture will be richer.
I can say for sure that with my 180* stat the ECM definately enters closed loop. This was verified by using the scan tool.

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87GT 3.4 Turbo Best 0-60 5.2 seconds
http://turbofiero.fierojoe.com/turbo.htm

For those of us who don't know what closed loop means, would you mind filling us in? I know it's an electroics term,related to binary code, but I don't know what the ecm does differentyl while warming the engine up except for the automatic choke.

Since I only plan to run my car when it's warm, and the fiero is known for running hot, why wouldn't I want to run a 160F thermostat? The water pump is always spinning, although it does put drag on the engine when pushing fluid through the radiator.

Cooling is the next project I'm working on so any suggestions (starting from stock parts that may or may not work) would be greatly appreciated.

Thanks.

Simply put, when the engine is in "open loop" it is sort of in a limp mode. The computer does not have total control over the system. "Closed loop" means that the computer takes over control of the runability.

One of the criteria that puts the car on open loop is a cold engine. The car will run best at proper operating temperature.

Many people think that a lower temperature thermostat will keep the car from overheating, but if a car it heading twords overheating (235 plus) both the 160 or a 195 degree thermostats are wide open.

I installed Rodney's low temp switch and 180 degree thermostat and the car ran like a spotted ass ape and NEVER EVER got too hot. Just do it and don't worry about it.

I will run the switch and a 180 degree stat on the V8, too.

I ain't skeered!

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FYI, I'm running Rodney Dickman's 180° thermostat and matching fan swtich (205° on/ 195° off, I believe). My fan only cycles more sitting in traffic. It rarely, if ever, comes on while driving. I recently passed an emissions inspection with flying colors (lower than my '99 Grand Am, actually), and I just took a road trip where I got 33mpg on the highway. I'm happy with the way it's running.

So if the fan doesn't turn on when it's supposed to, and I get a lower temp switch, say, from Rodney. Is the fan going to work, or are there other parts between the fan switch and the fan? I'll check to see if the motor works, but I need to find relays and other stuff too.

My car has some cooling issues:

very small leak around coolant tube, which I recently replaced, so I'll tighten it up

last time I heated the car to fan start temp, the coolant boiled over, in the front, and I had to let it cool down

my radiator overflow isn't stock, because it was broken. I can get one from my parts car though.

Is that a radiator cap issue? I just flushed the system, so besides the cap, thermostat, and overflow tank, I suppose there shouldn't be anything keeping me from driving the car (cooling wise).

is there anything else I should check for safety? What should I plan on doing about the fan switch?

Thanks.

I have a GN temp switch (I don't know what temp it is, but my friend is into GNs so he had an extra)At first I was missing the seal for my 195 therm. and NEVER got hot, it sat about 160, and I live in vegas! Then I got a new 195 therm. and it gots hotter....but I have never seen it hit the 220 mark not even in this 120 heat. Hope this helps.

...at least we didnt get "I'll leave the thermostat out" thing going again. You;ll have high idle years that way...lol and by the way ...Fiero stores lower switch 190 stat...misreds real happy, yes fan runs more...but so does my cooling blower
Red

I've been running Rodney's 180 thermostat and 190 fan switch for about a year too... Runs perfectly! I guess I'm just an old guy from back when cars were running 180 normally. If my car gets above 220 I start freaking out!

I did the same thing in my Corvette with the 160 thermostat and ThermoMaster chip. Amazing difference in the car.. I loved it!

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The Fiero Store has both low temp(176)fan switch and 160 thermostat. I have them both but not yet installed ...

save yourself some money and install a manual fan switch

simply T into the wire for the fan switch, then run that wire to a switch, then from the switch to a ground. when you flip the switch it completes the ground and turns on the fan(s). BUT since it's T-ed in the fan will still come on when it hits 220 if you forget to hit the switch.

This is what I did and i have a 180 thermostat that i got from pep-boys for 8 bucks

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--Adam--
1987 Blue GT 5-speed
IM AOL: FieroGT5speed

Here's just a note. I had a bad thermostat in my Mustang 5.0. I'm a cheap and lazy bastard (didn't feel like spending the 2 bucks for a new one) so I took it out. I got way better performance at lower temps. So when I finally replaced it, I rigged it so it wouldn't close all the way. Took alot longer to warm up, but the performance boost was way noticable.

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... if it's too fast, you're too old ...

Must not have emissions test where you live, DeViANT.

[QUOTE]Originally posted by GTFiero1:

I agree with the manual fan switch as I installed one last year. And since I drive the Southern Cal hwys well that was the wisest move. As I can turn it on or off when I am at a STANDSTILL!

quote Originally posted by Dennis LaGrua: I run an 180* thermostat and a 190* fan switch. It may be one of my pet quirks but I dislike running my engine with the coolant near the boiling point of water. When one runs a turbocharged engine as I do, excessive heat can trigger detonation. This does operate the fan more often but Fieros in the hot So. Western region will run with their fans on all the time anyway. As soon as that A/C buttom is pushed, the fan comes on. I believe that the cooling fans were designed for continuous operation.

I agree entirely. GM made our cars and all the GM cars run so hot, not because the car ran better, but because the emissions were better. Pure and simple. Much easier to maintain the emissions level at a higher temp with fewer changes and the addition of additional parts to keep the emissions down which we know that each little part cost GM much much money. It's a monetary thing, not a "good running" thing.

Phil

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87 FIERO GT 2.8 5spd
0-60 in 6.8 seconds!
87 FIERO CPE 2.5 5spd
86 FIERO SE 2.5 AUTO
87 FIERO GT 2.8 4SPD
If you found my advice helpful, please take the time to give me a positive rating. Thanks

Open loop is not limp home mode.

Allow me to educate the PFF community: straight out of a 1988 GM STG EFI publication:

Open Loop

When the engine is first started, and engine speed is above 400 RPM, the system goes into OPEN LOOP operation. In OPEN LOOP, the ECM will ignore the signal from the Oxygen (O2) sensor, and calculates the air/fuel ratio based on inputs from the coolant and map sensors.

The system will stay in OPEN LOOP until the following conditions are met:
1) The O2 sensor has a varying voltage output, showing that it is hot (600 degrees F) enough to operate properly.
2) The coolant sensor is above a specified temperature (usually 150 degrees F).
3) A specific amount of time has elapsed after starting the engine (usually 2.5 minutes).

Closed Loop

The specific values for the above conditions vary with different engines, and are stored in the PROM. When these conditions are met, the system goes into CLOSED LOOP operation. In CLOSED LOOP, the ECM will calculate the air/fuel ratio based on the signal from the O2 sensor. This allows the air/fuel ratio to stay very close to 14.7:1.

As I said, this info was taken directly from the GM Product Service Training Fuel Injection publication (16009.10-1A), published in 1988. In addition to the above information, there is also a POWER ENRICHMENT MODE that the ECM enters under certain conditions that will cause the ECM to ignore the O2 sensor readings and command a richer A/F mixture. During PE mode, the ECM may report that it is in CLOSED LOOP, when in fact PE overrides CLOSED LOOP operation. Just a little info.

As far as will a lower temp fan turn on hurt anything? Probably not. The only reason why GM runs hi temp fan switches is because they used it as an engine cleaning feature. At the higher engine temps, the carbon inside the cylinders and on the pistions is supposed to flake or burn off to prevent buildup. This is the official reasoning behind the grossly high engine temp fan turn on temps. Hope this info helps.

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1987 Fiero Coupe 3800 Series II Intercooled Turbo
1987 Trans Am GTA 5.7L Superram 4L60-E
1985 Fiero SE 2.8 (soon to have an L36)

Fiero-related Conversions Performed:
1985 SE 3800 Series 1 SC 4T60-E
1987 Coupe 3800 Series II Turbocharged 4T60-E
1987 SE 3.4 TDC 5-speed
1984 Coupe SBC V8 non-OD to 4T60 OD swap, electric power steering install
1985 SE 3800 Series II Supercharged 4T60-E

http://dtcc.cz28.com

[This message has been edited by Darth Fiero (edited 07-17-2003).]

quote Originally posted by West Coast Fiero: Bare in mind that this will cause the fan to operate more frequently, alternator will work harder to put out the amps for the fan, engine will take longer to reach closed loop causing longer high idle at start up, as well as poor fuel effeicency as the computer will see the lower temp and will constantly be dumping gas in the mixture ( hence the high idle ) in a futile attempt to raise the temperature to see closed loop.... Few of many thing to keep in mind when running a low temp switch

I use a 190*F fan switch and don't notice the negative effects which you claim. Better to keep the engine a bit cooler than have it overheat and blow a head gasket. ( did this on my 3100 Monte Carlo) BTW, the fan runs continuously if the A/C is turned on. In states and regions with hot climates I would imagine that the A/C is going most all the time anyway so the electric fan never turns off. These fans were designed for continuous operation, were they not?

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87GT 3.4 Turbo Best 0-60 5.2 seconds
http://www.turbochargerpower.com/turbo.htm

The nimrod who owned my 85 2m4 took it offroading a lot. Ripped off the air scoop and the grille, as well as breaking most engine mounts and twisting the front cross member of the cradle... Anyway, After fixing the broken fan switch wires and getting a new head cause he cracked the old one, I made sure there was a new fan switch in the new head. Yeah, it turned on, but only after the warning light lit and my coolant bottle started puking all over the road. Even driving at highway speed the thing would overheat because I can't find an airscoop locally. Heck the front end was damaged so badly underneath that I can't even attach an airscoop. But my point is, even after I had tried a lower temp thermostat, (140 f!) the thing would still overheat, until I stuck a manual switch in the line, then no problem. But if I forgot to hit that switch, I'd only get 15 K's before I would have to let it cool down.
When I get the thing running I guess I'll have to make a scoop. Good way to learn fiberglass work!

Let me chime in on the side of the lower temp fan switch.
After working out my recent cooling problems, I talked to a guy at Stant's tech support. It appeared to me that overheating had damaged my thermostat. Stant's tech support guy told me that (as a rule of thumb), a thermostat will be damaged when it reaches 45 degrees f above its rated temperature. For example, a 195 degree thermostat will start taking damage at 240 degrees. The damage is in the form of the wax (that causes the thing to open) being forced out of the casing. The result will be that the damaged thermostat will open at a higher temp, and not open as far. It seems to me that the stock fan switch turns on the fans dangerously close to the temp at which the thermostat will be damaged. This also suggests that using a lower temp thermostat, without lowering the fan switch temp will eventually result in a damaged thermostat.
I hope this helps.
Bill Temple