Normal Operating Temp
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Junior User
Joined: Mar 2003
Posts: 86
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From: Albuquerque, NM
Normal Operating Temp
Dear Gang,
I have a 72 F-100 with a 302. It seems to have an issue about running hot. When the temp gets above 200 it tends to stall and doesn't want to start again until it cools for a while? Is this normal or is there something I can do to help its feelings.
I have to say that we have been having temps in the upper 90s and 100 this week in Albuquerque.
Any thoughts?
Thanks,
Tony in New Mexico
I have a 72 F-100 with a 302. It seems to have an issue about running hot. When the temp gets above 200 it tends to stall and doesn't want to start again until it cools for a while? Is this normal or is there something I can do to help its feelings.
I have to say that we have been having temps in the upper 90s and 100 this week in Albuquerque.
Any thoughts?
Thanks,
Tony in New Mexico
Post Fiend
Joined: Jun 2002
Posts: 13,873
Likes: 3
From: Atlanta GA
Normal Operating Temp
I would replace the thermostat with a 160 degree, it will not solve a problem, but, might help mask it for a while for $5, and check the water pump.
Without cutting your hand off, check the upper hose (usually the
block to radiator) and see if it gets very hot. Then shut off the engine and check the lower one to see if it is much cooler (radiator is working).
A 302 in an older truck should not run hot at all with all that radiator space.
The truck stalling out is most likely a vapor lock problem because the carb. is getting too hot because the engine is too hot.
Without cutting your hand off, check the upper hose (usually the
block to radiator) and see if it gets very hot. Then shut off the engine and check the lower one to see if it is much cooler (radiator is working).
A 302 in an older truck should not run hot at all with all that radiator space.
The truck stalling out is most likely a vapor lock problem because the carb. is getting too hot because the engine is too hot.
Thread Starter
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Junior User
Joined: Mar 2003
Posts: 86
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From: Albuquerque, NM
Normal Operating Temp
Dear Robocardo,
Thanks for the heads up. I suspect that the problem lies with either the engine fan not pulling enough air in or the radiator is not workin very well.
When I am headed lown hill, the truck seems to maintain a regular cooler temp. On level ground or going up hill the temp gradulally raises.
I drove it this AM and it did fin, but the temp outside was only about 85 degrees.
Is it possible to get a bigger radiator?
Thanks,
Tony
Thanks for the heads up. I suspect that the problem lies with either the engine fan not pulling enough air in or the radiator is not workin very well.
When I am headed lown hill, the truck seems to maintain a regular cooler temp. On level ground or going up hill the temp gradulally raises.
I drove it this AM and it did fin, but the temp outside was only about 85 degrees.
Is it possible to get a bigger radiator?
Thanks,
Tony
Junior User
Joined: Jul 2003
Posts: 61
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From: Bothell, WA
Normal Operating Temp
When I went to NAPA to get my new radiator there appeared to be lots of choices. I think there are two sizes and two thicknesses (3 ro 4 row).
Do you still have the shroud around your radiator/fan? This can actually make quite a difference to the efficiency of the fan.
Good luck
Kevin
Do you still have the shroud around your radiator/fan? This can actually make quite a difference to the efficiency of the fan.
Good luck
Kevin
Posting Guru
Joined: May 2003
Posts: 1,393
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From: Thomson, GA
Normal Operating Temp
If you can get hold of a temp. probe, get the truck to normal temperature and check the top and bottom radiator hoses. The top should be about 15* cooler if I am not mistaken. Or if you are the rough and tough type, or lazy and don't want to find a probe, fell the hoses. I gaurentee they will be hot, both of them. If you do decide to grab them and burn yourself, don't tell us, or we will laugh at you.
Post Fiend
Joined: Jun 2002
Posts: 13,873
Likes: 3
From: Atlanta GA
Normal Operating Temp
>Is it possible to get a bigger radiator?
Get a four core radiator for a 390 with A/C. That is about the biggest you can get. My 390 does not even get 1/2 way across the factory gauge in 100 degree weather, without a fan shroud.
Get a four core radiator for a 390 with A/C. That is about the biggest you can get. My 390 does not even get 1/2 way across the factory gauge in 100 degree weather, without a fan shroud.
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Junior User
Joined: Mar 2003
Posts: 86
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From: Albuquerque, NM
Normal Operating Temp
Dear Guys,
I think I may have figrued out the issue. As I have said, the 302 in it is not the origiinal engine. It appears that the fan is not square in the center of the radiator core. I assume that when the recent engin e was put in, it went in a little high.
Was wondering iwhat would happen if I raised the radiator up a few inches?
Your thoughts?
Tony
I think I may have figrued out the issue. As I have said, the 302 in it is not the origiinal engine. It appears that the fan is not square in the center of the radiator core. I assume that when the recent engin e was put in, it went in a little high.
Was wondering iwhat would happen if I raised the radiator up a few inches?
Your thoughts?
Tony
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Junior User
Joined: Jul 2003
Posts: 61
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From: Bothell, WA
Normal Operating Temp
I'm not convinced this would account for the severity of problem you're seeing. I think the presence or absence of a shroud might make more difference than whether or not the fan was in the middle of the radiator, unless it's a long way off. I think it would be less trouble to try and fit a junk yard shroud than it would be to move the radiator up.
If you pop open the hood with the truck idling, I assume you feel a great blast of hot air blowing back over the engine from the fan? On my truck the air stream from the top of the fan is hotter than at the bottom, which is pretty much what you would expect. Even just at idle there's a real gale blowing back.
What's the diameter of the fan? How many blades? Mine appears to be 18" across, it's 5 bladed with two of the blades much closer together than the others. Odd looking.
I assume you've also checked that it's not running lean? If you had a vacuum leak somewhere you might run a bit lean, and tends to run it hot too.
Good luck
Kevin
If you pop open the hood with the truck idling, I assume you feel a great blast of hot air blowing back over the engine from the fan? On my truck the air stream from the top of the fan is hotter than at the bottom, which is pretty much what you would expect. Even just at idle there's a real gale blowing back.
What's the diameter of the fan? How many blades? Mine appears to be 18" across, it's 5 bladed with two of the blades much closer together than the others. Odd looking.
I assume you've also checked that it's not running lean? If you had a vacuum leak somewhere you might run a bit lean, and tends to run it hot too.
Good luck
Kevin
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Post Fiend
Joined: Jun 2002
Posts: 13,873
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From: Atlanta GA
Normal Operating Temp
FWIW
A fan shroud should completely cover the fan blades, so you can not see them. I agree with KC about the centering not being that important as long as you are on the core. Being at the top is better than being at the bottom with the center being ideal.
I know in my truck, even at 900-1000 rpms, it is a gale force under the hood without a shroud. Maybe your solution is as easy as a fan replacement. You can get them from junkyards for $5 or $18 brand new from Summit Racing.
It would not hurt to power flush the truck. When I bought my $300 BII it had heating/cooling problems and never got hot with the defroster. I decided to flush it and the problem was the coolant was so bad it was sludged and caked around the sensor and throughout the radiator. So I ditched the radiator and heater core and flushed the block until it ran clean.
A fan shroud should completely cover the fan blades, so you can not see them. I agree with KC about the centering not being that important as long as you are on the core. Being at the top is better than being at the bottom with the center being ideal.
I know in my truck, even at 900-1000 rpms, it is a gale force under the hood without a shroud. Maybe your solution is as easy as a fan replacement. You can get them from junkyards for $5 or $18 brand new from Summit Racing.
It would not hurt to power flush the truck. When I bought my $300 BII it had heating/cooling problems and never got hot with the defroster. I decided to flush it and the problem was the coolant was so bad it was sludged and caked around the sensor and throughout the radiator. So I ditched the radiator and heater core and flushed the block until it ran clean.
Post Fiend
Joined: Apr 2002
Posts: 7,157
Likes: 1
From: Central Kali
Normal Operating Temp
Y not, I like that. 
If your radiator is old, you might want to have a shop rod it out. I have a Mustang that in 6 years after it was new had about 25% of the tubes blocked with crud.
If your radiator is old, you might want to have a shop rod it out. I have a Mustang that in 6 years after it was new had about 25% of the tubes blocked with crud.
Senior User
Joined: Jun 2003
Posts: 152
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Normal Operating Temp
I am not sure that your stalling while hot problem is related to your truck running hot... Where are your fuel lines located? Are any of them running close to the engine? If they're too close to a hot surface, the gas can litterally boil and evaporate, causing vapor lock. After it sits for a bit it usually will start right up again.
Try running without a thermostat and see if that helps. If not, yank the rad out and get it checked at a radiator shop. Also check your fan when running... Where does air blow when you step on the gas? Make sure the fan isn't on backwards.
I went through the same problems last year with another Ford vehicle that I had just dropped a motor in.
Try running without a thermostat and see if that helps. If not, yank the rad out and get it checked at a radiator shop. Also check your fan when running... Where does air blow when you step on the gas? Make sure the fan isn't on backwards.
I went through the same problems last year with another Ford vehicle that I had just dropped a motor in.
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1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
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Jul 23, 2001 10:50 PM