What is Operating Temp for 87 Gt?

T

Thunderboy

New Member

Aug 2, 2004

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Apple Valley, CA

Mar 7, 2008

#1

• Mar 7, 2008

• #1

Alright I've got an 87 Gt that I have no clue what temp it should be running at. I had replaced the head gaskets a while ago because the water pump went out on me on my way to work and I didn't even notice anything until i parked it. So after I fixed the water pump, temp gauge (that was not working) and replaced the thermostat and everything, it ran hot (around 250 if I were to guess). What's normal? I have a thermostat in there right now that is set to open at 160 but I know that is obscenely low. Any help here would be much appreciated cuz my gas mileage is suckin' big time.

 

Fast63

New Member

Sep 20, 2007

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Mar 7, 2008

#2

• Mar 7, 2008

• #2

250 if you were to guess? based on what? I hope you're not basing that off the stock gauge. Get an aftermarket gauge to show what you're really at. The stock thermostat rating is 195, and you really shouldn't use anything cooler than that. How bad is your gas mileage? What kind of miles per gallon? Running cold, like 160 degrees all the time will definitely hurt your mileage, but so will overheating all the time.

 

Ike83

Member

Sep 27, 2006

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17

St. Louis, Missouri

Mar 7, 2008

#3

• Mar 7, 2008

• #3

I've heard TWO different theories here...

Most folks shoot for a 180 thermostat in an effort to keep the engine cooler during normal operating temps. However, I've also been informed that the BEST operating temperature for the Mustang (i.e. best temp for engine combustion efficiency) is around 205 degrees fahrenheit. That's (apparently) the temperature with which the pistons have swelled (remember when things get hot they expand ) to fit the cylinder walls perfectly and the fuel is being combusted at it's most efficient rate.

That's just what I've heard though......

 

Ike83

Member

Sep 27, 2006

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St. Louis, Missouri

Mar 7, 2008

#4

• Mar 7, 2008

• #4

I know when I'm at normal operating temp my Autometer gauge reads 205 and she's ready to rumble.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

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Mar 7, 2008

#5

• Mar 7, 2008

• #5

Since you have a 160 t-stat, you should be at 150-170*F while cruising if you have a balanced stat and 160-180*F if it's an unbalanced stat.

If you heat up only while idling, the fan and clutch are things to consider.

As noted, you need a real gauge, plain and simple. It's the only way to know if there's an issue or do any diagnostics.

Good luck.

 

T

Thunderboy

New Member

Aug 2, 2004

16

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Apple Valley, CA

Mar 7, 2008

#6

• Mar 7, 2008

• #6

Yeah I was estimating my temp from the stock gauge (not the best idea I know). But I had no clue where the temp should be, or if the thermostat that I replaced the old one with was even the same because it was definitely an aftermarket stat that I pulled out. But now that I have an idea on the range I'll get 'er back in there cuz Ive been getting like 12 MPG lately when I was getting 19. Thanks a ton

 

Roland69

Sergeant Tangnet

Sep 17, 2005

2,867

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58

Port Elgin, Ontario

Mar 7, 2008

#7

• Mar 7, 2008

• #7

160 is too cold... at least a 180 or a 195. the car will burn less fuel the warmer it gets. 160 and it will be still in warm up mode

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,217

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Massachusetts

Mar 8, 2008

#8

• Mar 8, 2008

• #8

190-210 is proper temp.

My car stays around 188*