289 Operating Temperature

robbz28

Member
Sep 23, 2009
775
5
19
Epps, LA
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...?
 
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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!
 
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!
 
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.
 
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?
 
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?