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289 Operating Temperature

  • Thread starter Thread starter robbz28
  • Start date Start date Aug 3, 2012

robbz28

Member
Sep 23, 2009
775
5
19
Epps, LA
Aug 3, 2012
#1
  • Aug 3, 2012
  • #1
I took my car out for its longest drive yesterday, nearly 300 miles on the hottest day of the year so far in the southern delta heat. The car did fantastic, cruised around and it stayed around 185, would bump up to 190 in town....until I got stuck in a wreck with no turning back. I sat there for about 10 minutes just easing forward when I got the chance (A/C on max) and i kept a close watch on my temp gauge, it eased up to around 205 (which does not worry me, just the hottest it's ever been). At that point I looked over at my factory gauge (which I have never seen work) and it was reading halfway between Cold and Hot. I was excited to see that my gauge did indeed work, just that it don't start moving off of C until around 190, at the rate it was going up, I would imagine 220 would have it over on H. So, with that said, anyone have a clue as to what Ford intended the 289 to run? I would assume around 200ish since that's when my gauge started to actually work...?
 

PoppyMod

Member
Jun 27, 2010
617
6
19
Severna Park, MD
Aug 3, 2012
#2
  • Aug 3, 2012
  • #2
Hi,
When your engine temps start to approach the mid 220s, it's time to worry. But then, the accuracy of your gauge is of major importance, as well. Someone, may chime in with what the factory spec was, but, my junk runs around 205, maybe, 210 in traffic with ambient temps in the mid/high 90s. I run a 4 row rad, a shroud, 17" 5 blade flex, 180 deg. T/S, and a coolant recovery system. I run a mechanical and the OEM temp gauge.
Good Luck!
 

robbz28

Member
Sep 23, 2009
775
5
19
Epps, LA
Aug 3, 2012
#3
  • Aug 3, 2012
  • #3
Yeah, I have two gauges as well (as mentioned before). I have a thick 2 row aluminum radiator, with an 18" electric fan on a thermostat and a 180 degree ts and a recovery system as well. I am very pleased with how my cooling system performs in the muggy delta heat...you have to swallow your air down here this time of year!
 

rbohm

Founding Member
Apr 12, 2002
6,698
550
204
tucson,az
Aug 3, 2012
#4
  • Aug 3, 2012
  • #4
the factory put in a 192 degree thermostat when they built these engines, and they expected them to run at about 205-210 degrees.
 

robbz28

Member
Sep 23, 2009
775
5
19
Epps, LA
Aug 3, 2012
#5
  • Aug 3, 2012
  • #5
rbohm said:
the factory put in a 192 degree thermostat when they built these engines, and they expected them to run at about 205-210 degrees.
Click to expand...

Well that would explain why the C = 190 and the H = 230 (I assume)...oh well just glad to know my gauge does indeed work.
 

gilzuckie

New Member
Nov 3, 2018
24
0
1
Anaheim, CA
Nov 3, 2018
#6
  • Nov 3, 2018
  • #6
Hello robbz28, I have that same question. I recently upgraded to a large 2 row aluminum rad with a 16" electric fan and shroud. When my temp gauge is 1/2 way between C-H I'm pretty sure that is 200° but still want to make sure. Looking to put in a mech gauge. I was having an issue with overheating and blowing past the cap. Found out that it was a bad cap, would not hold pressure. It was one of those pressure release caps. Many people have told me that those caps are junk so I put a stock cap on. Good so far.
 

WORTH

20+ Year Stangneter
Nov 18, 2002
2,166
44
98
Cape Cod, Ma.
Nov 4, 2018
#7
  • Nov 4, 2018
  • #7
Your gauge should start moving somewhere around 100-120, and operating temp can vary, but 195-220 is a good rule.
 
T

TDGooldy

New Member
May 7, 2019
3
0
1
Orlando
May 7, 2019
#8
  • May 7, 2019
  • #8
I have a 1966 Mustang convertible with a 289, on the street it runs 195-205, but when I take it out on the highway after 15 mins running at 65-70 mph the temp crawls up to 220-225. It then tends to stay up around 220 when I am back on the streets. (Using an infrared thermometer) If I try to start it up again soon after it starts hard and squeals a little. It has a 3 year old Aluminum 3 row radiator with coolant recovery system, electric fan with shroud, timing just checked, 14 lb radiator cap is not leaking, lower radiator pipe does not appear to be flattening. It does not boil over, but runs hotter than I would like. My mechanic suggested that it may be the electric fan running on the highway limiting the amount of air that flows through. Any thoughts on what to check next?
 

Realmongo

I prefer to be called "Evil Genius"
Founding Member
Oct 10, 2001
2,468
86
99
Western Mass
May 7, 2019
#9
  • May 7, 2019
  • #9
I just checked the Ford Parts Manual.
The '65-'67 Mustang got a 190 Degree thermostat from the factory.
Part Number A8AZ-8575-C
 
T

TDGooldy

New Member
May 7, 2019
3
0
1
Orlando
May 7, 2019
#10
  • May 7, 2019
  • #10
Realmongo said:
I just checked the Ford Parts Manual.
The '65-'67 Mustang got a 190 Degree thermostat from the factory.
Part Number A8AZ-8575-C
Click to expand...
Do you think that the thermostat I have now is potentially failing?
 

Realmongo

I prefer to be called "Evil Genius"
Founding Member
Oct 10, 2001
2,468
86
99
Western Mass
May 7, 2019
#11
  • May 7, 2019
  • #11
It's possible, but good quality thermostats are usually pretty reliable. The only one I ever had really fail was one that stuck open and the car never got up to operating temperature. What temperature thermostat do you have in it now?
 
T

TDGooldy

New Member
May 7, 2019
3
0
1
Orlando
May 7, 2019
#12
  • May 7, 2019
  • #12
Not sure as I haven't replaced it since purchasing the car. Any other thoughts on what I might do next?
 

Realmongo

I prefer to be called "Evil Genius"
Founding Member
Oct 10, 2001
2,468
86
99
Western Mass
May 7, 2019
#13
  • May 7, 2019
  • #13
It might be worth a look to swap out the thermostat then.
 
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