HELP! Cooling problems
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Elder User
Joined: Aug 2000
Posts: 597
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From: Burke VA
HELP! Cooling problems
This thing is killing me!
I have a 78 short bed that I put a 351W in. It has a new radiator, water pump, thermostat, and hoses. When I first drove it after the installation it would get hot (in the A on thr N-O-R-M-A-L gauge). I couldn't find a fan shroud so I went with a 16 inch electric w/a dash mounted switch. I kept the clutch fan on as well. It still ran in the A. I picked it up from the paint shop 2day and drove it home (night, temp in the 70's). The gauge fluctuated between the A and the L.When I got home, I parked it and noticed it went to normal operating temp (stat opened, I guess). I let it idle for 15 minutes (elec fan off)aand it was back at L. What's wrong? should I replace the stat? get a flex fan? a shroud? dump the electric?
I need to drive this thing to MO from CO on thursday so I need to get this squared away.
PS, there's lots of coolant in it.
I have a 78 short bed that I put a 351W in. It has a new radiator, water pump, thermostat, and hoses. When I first drove it after the installation it would get hot (in the A on thr N-O-R-M-A-L gauge). I couldn't find a fan shroud so I went with a 16 inch electric w/a dash mounted switch. I kept the clutch fan on as well. It still ran in the A. I picked it up from the paint shop 2day and drove it home (night, temp in the 70's). The gauge fluctuated between the A and the L.When I got home, I parked it and noticed it went to normal operating temp (stat opened, I guess). I let it idle for 15 minutes (elec fan off)aand it was back at L. What's wrong? should I replace the stat? get a flex fan? a shroud? dump the electric?
I need to drive this thing to MO from CO on thursday so I need to get this squared away.
PS, there's lots of coolant in it.
Posting Guru
Joined: Mar 2001
Posts: 1,494
Likes: 0
HELP! Cooling problems
I've noticed funny things lately with my 300-6. Personally, I've just accepted the occasional high temp range - if it doesn't blow a hose or cap, I'm COOL. Actually, I get better gas mileage with the slightly higher temp. I don't know what tranny you're runnin' but, why not try a tranny cooler (even though I don't think it would affect temp while not moving). Another idea is too install a new sender unit, or maybe an extra guage that's a little more informative than A or L. Just a thought.
Junior User
Joined: Aug 2001
Posts: 88
Likes: 0
HELP! Cooling problems
I have had old Ford trucks all my life and the one problem that all of them had was overheating, All you can do is keep trying, You know check radiator, thermostat I even ran one without a thermostat and it still got hot, turned out to be the timing was to advanced, sometimes its the sending unit,
Just don't give up you will find it,
A good flex fan is a good investment also, those little rigid fans Fords have are'nt very good coolers,
My 2cents
Benny
Just don't give up you will find it,
A good flex fan is a good investment also, those little rigid fans Fords have are'nt very good coolers,
My 2cents
Benny
Junior User
Joined: Aug 2001
Posts: 88
Likes: 0
HELP! Cooling problems
I have also been told that the old freeze plugs that some rebuilding shops just knock them in to the engine , and they restrict the water flow through the engine ,
Don't know if this is true , just a thought
does your truck boil over ?
if not I would try the sending unit next
Don't know if this is true , just a thought
does your truck boil over ?
if not I would try the sending unit next
Cargo Master
Joined: Mar 2001
Posts: 2,759
Likes: 71
From: Elk River, MN
HELP! Cooling problems
A fan shroud is a must for idling in warm weather (80F). Without it the air does not all go through the radiator. The air is drawn in all around the fan instead of from the front and thru the radiator. Going down the road, the shroud is probably not all that necessary, but as soon as you stop, the temp will creep up without adequate air flow being drawn past the radiator core.
Lead Driver
Joined: Nov 2000
Posts: 6,647
Likes: 352
From: Albuquerque
HELP! Cooling problems
I concur on the shroud. It really is needed. Also be sure your clutch fan is working properly. They tend to go away over time and not lock up. An RV heavy duty clutch/thermo fan has worked for me in the past. Also your gauge could be wrong/erratic. An after market one would be good to have or at least to compare to.
1977 Ford F-100
400m/c6/4:11/Gear Vender O.D.
Crane hydralic roller, forged, ported polished,Deamon,Edlebrock, yada, yada, yada
280,000 miles
Stock on the outside
modified/rebuilt everything
1977 Ford F-100
400m/c6/4:11/Gear Vender O.D.
Crane hydralic roller, forged, ported polished,Deamon,Edlebrock, yada, yada, yada
280,000 miles
Stock on the outside
modified/rebuilt everything
Trending Topics
Post Fiend
Joined: Feb 2000
Posts: 5,130
Likes: 8
From: Brea CA
HELP! Cooling problems
Before adding on the cooling goodies, check your thermostat for proper operation, it may be sticking. Put the stat in a pan of water on the stove with a thermometer and raise the heat slowly while looking at the valve. It should just crack open at it’s rated temperature and be fully open around 15 – 20 degrees above the rated temperature. Sometimes it’s hard to see when it starts to open, shine a flashlight on it when the temperature reading is close to the opening point.
I always test new thermostats before installing, it’s a lot easier on the stove than in the engine. I also like to drill a small bleed hole at the top to help purge any air that may get trapped behind the stat when it’s closed. The trapped air can delay the stat opening by acting as an air lock, keeping coolant from touching the stat.
Barry
I always test new thermostats before installing, it’s a lot easier on the stove than in the engine. I also like to drill a small bleed hole at the top to help purge any air that may get trapped behind the stat when it’s closed. The trapped air can delay the stat opening by acting as an air lock, keeping coolant from touching the stat.
Barry
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Senior User
Joined: Apr 2001
Posts: 321
Likes: 1
HELP! Cooling problems
Hi OFT,
I just solved the same problem in my 79 truck. Turned out to be the voltage regulator in the back of the instrument cluster. The ground was bad, and caused the gauge to bo bizzare things. I found the problem because it seemed that when the truck was "overheating", I also all of a sudden had a full tank of gas and high oil pressure! I also have no fan shroud on my truck.
Does the motor ping or make funny noises when it is "hot"? Do the rad hoses seem like they are as hot as the gauge indicates?
Just a thought, perhaps the truck isn't overheating, but the gauge is mis-leading you.
-brents
I just solved the same problem in my 79 truck. Turned out to be the voltage regulator in the back of the instrument cluster. The ground was bad, and caused the gauge to bo bizzare things. I found the problem because it seemed that when the truck was "overheating", I also all of a sudden had a full tank of gas and high oil pressure! I also have no fan shroud on my truck.
Does the motor ping or make funny noises when it is "hot"? Do the rad hoses seem like they are as hot as the gauge indicates?
Just a thought, perhaps the truck isn't overheating, but the gauge is mis-leading you.
-brents
Thread Starter
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Elder User
Joined: Aug 2000
Posts: 597
Likes: 0
From: Burke VA
HELP! Cooling problems
Well, it was the gauge. I put a new one in and the truck didn't get above 190. What a relief!Once again, I am so glad I found this site.
Thanks again!
Jayson
Thanks again!
Jayson
Lead Driver
Joined: Nov 2000
Posts: 6,647
Likes: 352
From: Albuquerque
HELP! Cooling problems
Alright, a friend once told me to always look for the simplest cause first. It works out many times.
1977 Ford F-100
400m/c6/4:11/Gear Vender O.D.
Crane hydralic roller, forged, ported polished,Deamon,Edlebrock, yada, yada, yada
280,000 miles
Stock on the outside
modified/rebuilt everything
1977 Ford F-100
400m/c6/4:11/Gear Vender O.D.
Crane hydralic roller, forged, ported polished,Deamon,Edlebrock, yada, yada, yada
280,000 miles
Stock on the outside
modified/rebuilt everything
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