emo-vet

hi guys,
i have just ordered a low fan temp switch and harness which is a 190 degree on/ 175 degree off kit.

btw the way guys i am running a emp /robert shaw modded/balanced 180 degree thermo stat also...

can some one please tell me a bit about this!

where to fit it on a 1991 L98 engine please?

what tools are needed ?

is it hard to install ?

any other info please?

i have just now noticed that there is a 13/16 " brass fitting with a grey plug that is located in between #1 & #3 spark plugs in drivers side head up top near headers,is that it please ???

corvette central helper from there c4 catologue are saying that 90-95 vettes have a 3/8" water jacket plug that must be removed with a piece of 5/16" square tube, im confused now , as i just removed the plug that i needed a spanner 13/16" unless of course some one else has did this upgrade before may be before i brought the car as im the fifth owner belive it or not ???

when i used my hand held nemiys scanner the fans came on at 203 degrees farenheit and off at 192 degrees.

cheers and have a great weekend guys!
thanks
shae

86PACER

Who did you buy it from? Ought to come with install instructions.

On single fan cars, you need to undo this stupid one off sized pipe plug. Had to make my own tool. Took some serious torque to loosen it.

emo-vet

hi 86 pacer,
thanks for your pictures and help there!
i brought the low temp fan switch from ecklers.
im sure and hope it comes with instructions!
i havent recieved my fan switch yet as it is on its way, but i did already undo the 13/16 fitting and i beleive that it may already be aftermarket switch that someone has fitted already!
but i ordered a low tem sitch that what was in it!
cause im sure that there can only be one type of plug/fitting between # 1 & #3 spark plugs.
so we will see how we go!
cheers
shae

86PACER

Is this the one you bought?

http://www.ecklers.com/product.asp?p...0&dept_id=1748

emo-vet

hi there 86 pacer,
yeah similar switch but i ordered a 190 degree on ,175 degree off though, not 200 degree on !!
cheers
shae

thirdtimevetteowner

Shae,
Just wondering if they offer this switch in lower on/off temps than the one you bought? Thanks.

Rich K

emo-vet

hi rich,
yes mate there are lower fan temp switches.
there is also a 185 degree on and 170 degree off.
www.corvettecentral.com
#244381 @$39.95 each
cheers
shae

65Z01

I think HyperTech makes one that works around 160deg F; check with Summit.

Da Mail Man

.....i have a kit that comes on at 160 but, can't remember right off where i bought it.....

Can86Z51

Just a quick comment for those wanting a very low temp fan(s) switch, at least for earlier c4's. Early on(1988) I installed an adjustable main fan switch/relay on my late-86 coupe. Believe it or not, summer temps in Canada can get quite hot, and I quickly noticed that if I tried to set the 'on' temp-setting of my switch set-up too low - anything much below, say, 195 F., - my fan would run almost constantly in hot weather city traffic. Over the long term I now know that puts a real strain on the alternator, which at low speeds/city driving does not put out enough juice to adequately keep the battery fully charged. I discovered, by trial and error, that at least for my 86, a fan-'on' temp setting of approx. 197 or 198 F., was a good compromise. Not too low in hot weather, but low enough to be useful in keeping engine/underhood temps reasonable. I have been using this temp setting(197 F.) since 1988 to today with good long term success). On L98 C4's, I suggest NOT going too low on the fan switch, at least not for daily driver/summer driving. Just my opinion!

CFI-EFI

With that combination of parts, once on, your fan will never turn off.



You really don't want your fan on/off temps any lower than that. Your 1991 was built with no fan switch installed in the engine. The ECM controls both fans based on the input from the ECT sensor in the front of the intake manifold and a pressure switch in the A/C system. Your system has been previously modified, as evidenced by your present fan operating temps which are already much lower than the factory settings. You would be better off to leave it alone, at this point.

RACE ON!!!

emo-vet

hi cfi-efi,
thanks for your helpful info!
so what do i do now with this new switch ???
my old switch was broken off thats why i replaced and brought a new one you see!!!
will putting in a 160 degree thermo stat help the situtaion of the fans not staying on all the time please ??
as that is my main concern that the fans dont stay on all the time!!
please help then ???
cheers
shae

CFI-EFI

Send it back.



Was the broken switch (?) actually controlling the fans? I'm not sure of the fan and gauge sending unit locations for the '91. Could that have been a gauge temp sending unit that broke?



Very probably not. Especially at low speeds, your engine STILL won't run cool enough to shut the fans off. Coolant temps of under 180° aren't good for your engine and that 160° stat only serves to slow the warm ups, the stat is there to facilitate.

The first thing I would do, is confirm the broken part is really a fan switch. If not leave things alone. Your engine temps are great right where they are. If you need a fan switch, get one close to the one you had and forget the 160° stat.

RACE ON!!!

emo-vet

hi cfi-efi,
ok then mate i will send it back and get a 200 degree f on and off at 185 degree f then and run the 180 degree thermostat.
cheers
shae

CFI-EFI

That off temp is still too cool. Your fan will run much more than necessary with a 185° off setting. Look for an "On" temp of between 205° and 215°, and an "Off" of 195° to 205°. A 10° spread between the "On" and the "Off" is just about right.

RACE ON!!!

larryfs

Is there a list of switches and temps somewhere?
I got the GN switch in my basement, but I forget the temp range.

BADDUCK

If you only have one fan 200* on 185* off is too low. With two fans it's about right.
I use that one with a 180* stat and it works fine on my aux fan. Yeah, my front aux fan runs some in the summer but so what. That's why I did it!

larryfs

where would you find such a sensor ?
I havn't seen any in that temp rage.
the GN is 203 on, ??? off.

CentralCoaster

You probably should've bought the one Pacer linked.

Your fan is going to be running at 175F trying to cool down coolant, yet the coolant won't be moving or cooling down the temp sensor because the tstat is shut.

It'll be about as effective as a solar powered light switch.

CentralCoaster

CFI, my experience with 2 high flow RobertShaw 180F thermostats, and someone else's, is that they are substantially open by 175F.

I think he'll be fine with a 185F off and a 180F high flow stat.