Temperature Question

USCGunner

Active Member

Jun 10, 2017

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Idaho

Aug 4, 2017

#1

• Aug 4, 2017

• #1

My 91 Lx 5.0 constantly runs at around 160 deg no matter what the outside temp is. Is this correct or do I need to think about a new thermostat?

 

90sickfox

Wasn't a pretty sight...and I've got big hands

SN Certified Technician

Mar 2, 2015

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Aug 4, 2017

#2

• Aug 4, 2017

• #2

Someone mat have installed a 160 degree thermostat in it. The stock thermostat is about 192 degrees. You can disconnect the wire at the coolant temperature sensor and ground the single wire to the block to check the gauge operation.

On an EFI car the temp is important. 160 degrees won't allow the computer to go in closed loop....meaning it would run in warm up strategy all the time.

I'd advise at least a 180 degree T stat.

 

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imp

Mustang Master

Jul 13, 2017

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Aug 5, 2017

#3

• Aug 5, 2017

• #3

In summertime, especially in hot locations, the stat opening temp. is largely immaterial: the engine will operate at 200` or higher, no matter what stat is there. Where I reside, for example, thermostats are always wide open, 8 months of the year, regardless of their opening temp. So, under such conditions, the "closed-loop" problem becomes a moot point.

Still, I've always tried to picture the scenario in, say, Fargo, driving with a 160 in winter, would my EFI ever achieve "closed-loop"? Imponderable question. imp

 

Real time recon

Mustang Master

Aug 21, 2016

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...

Aug 5, 2017

#4

• Aug 5, 2017

• #4

My 90 GT 302/345 EFI (with 180* stat) runs at 180* +- 5* ALL the time after warm up.Doesn't matter what the air temp is.

 

mikestang63

SN Certified Technician

Aug 27, 2012

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Aug 5, 2017

#5

• Aug 5, 2017

• #5

EIther the thermostat is not installed or it is stuck open

 

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FoxMustangLvr

I love my Pimp

SN Certified Technician

Oct 14, 2012

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Spokane, Wa

Aug 5, 2017

#6

• Aug 5, 2017

• #6

I would never run a t-stat below 180*. If you can't cool your car then you need a better radiator and/or fan setup. If the fan kicks on shortly after the t-stat opens, the coolant temp should immediately start to lower. If it doesn't you have a problem and it's not your t-stat.

 

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Sparky714

5 Year Member

Oct 16, 2015

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North Dakota

Aug 5, 2017

#7

• Aug 5, 2017

• #7

imp said:

Still, I've always tried to picture the scenario in, say, Fargo, driving with a 160 in winter, would my EFI ever achieve "closed-loop"? Imponderable question. imp

Click to expand...

Being a North Dakota resident, I can safely say that you would have more to worry about driving a short wheelbase rear wheel drive Mustang on a slippery road in the winter in ND than if your ecu was going in to closed loop. Just sayin. And no, it would probably never get warm enough.

 

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imp

Mustang Master

Jul 13, 2017

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Aug 6, 2017

#8

• Aug 6, 2017

• #8

Sparky714 said:

Being a North Dakota resident, I can safely say that you would have more to worry about driving a short wheelbase rear wheel drive Mustang on a slippery road in the winter in ND than if your ecu was going in to closed loop. Just sayin. And no, it would probably never get warm enough.

Click to expand...

@Sparky714
Love your reply!! Wife & I flew to several places up there from PHX, seeking retirement possibilities. Billings, then Bismarck. Decided no. Lovely places in MT, went to Roundup, looked at a self-sufficiency set up in a canyon, water running constantly down from above. Guy lived there with his wife & kids, way, way, off the grid. We had done it before, so passed.

Again, love your reply! Thanks! imp

 

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Redfire Fox

Active Member

Dec 29, 2011

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Aug 6, 2017

#9

• Aug 6, 2017

• #9

I wouldn't go lower than a 192/195 stat. The car runs most efficient at that temp. Most engine wear occurs when the engine is cold.

 

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USCGunner

Active Member

Jun 10, 2017

60

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Idaho

Aug 11, 2017

#10

• Aug 11, 2017

• #10

Ok sorry to bring this back up but this car confuses the heck out of me. I have been driving this car for about two months now, like I said 160 deg is where it always set. Today outside temp 97 deg and the thermostat started reading 190 deg, why all of the sudden.

 

deathb4dismount

Crap, didn’t realize my crotch was in that picture

15 Year Member

Oct 6, 2011

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Aug 12, 2017

#11

• Aug 12, 2017

• #11

do you have an after market gauge or are you just going by the reading on the dash?

 

USCGunner

Active Member

Jun 10, 2017

60

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Idaho

Aug 12, 2017

#12

• Aug 12, 2017

• #12

Just the dash