Low Engine Temperature
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Low Engine Temperature
What would cause a low engine coolant temperature?
The truck is a 1989 F150 2wd. It has the 5 liter engine and aod tranny. No matter what speed I drive or for how long the temperature gauge shows just above the left edge. I replaced the thermostat with a 195 degree replacement and the problem continues. I have checked the temperature in the radiator with mechanical thermometer known to be accurate and it never gets above 145-150 degrees. Any info on what would cause this would be great. Thanks.
The truck is a 1989 F150 2wd. It has the 5 liter engine and aod tranny. No matter what speed I drive or for how long the temperature gauge shows just above the left edge. I replaced the thermostat with a 195 degree replacement and the problem continues. I have checked the temperature in the radiator with mechanical thermometer known to be accurate and it never gets above 145-150 degrees. Any info on what would cause this would be great. Thanks.
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From: Linwood, N.J. USA!
Low Engine Temperature
Tough one! It almost sounds to me that the new thermostat that you installed could be defective and not closing enough to allow the truck to warm up. The same would be for the original malfunctioning thermostat. Is this truck stock or are there any modifications that have been done which could possibly cause this situation?
Jakegypsum // Ford fleet, soup to nuts.
Jakegypsum // Ford fleet, soup to nuts.
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From: Poway, CA
Low Engine Temperature
this is probably a stupid question to someone who knows better, but what's wrong with a truck that runs cold? mine is a 1990 f150 L6 and it does the same thing, although it will raise up to about the o in normal if it's a long hill and i'm pushing it a little hard? i always thought a cool-running truck was a good thing.
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Low Engine Temperature
Now that is truly a head scratcher. I would have sworn up and down that the thermostat was stuck open, as I can't think of anything else that would cause this. I would next try taking the belt off the water pump and running the motor that way. If the motor builds up heat, then your thermostat has to be bad. If it doesn't, something is VERY screwy. I know all this is redundant, but thermodynamics forbids no coolant flow and no temperature increase. Good luck.
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Low Engine Temperature
The engine seems to run pretty well but might be a little short on power. Mileage could be better (13-15mpg).
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Low Engine Temperature
>this is probably a stupid question
>to someone who knows better,
>but what's wrong with a
>truck that runs cold? mine
>is a 1990 f150 L6
>and it does the same
>thing, although it will raise
>up to about the o
>in normal if it's a
>long hill and i'm pushing
>it a little hard? i
>always thought a cool-running truck
>was a good thing.
IT IS
>to someone who knows better,
>but what's wrong with a
>truck that runs cold? mine
>is a 1990 f150 L6
>and it does the same
>thing, although it will raise
>up to about the o
>in normal if it's a
>long hill and i'm pushing
>it a little hard? i
>always thought a cool-running truck
>was a good thing.
IT IS
Thread Starter
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New User
Joined: Apr 2001
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Low Engine Temperature
I read that with ford fuel injection that running lower than 180 degrees will cause decreased fuel economy, poor emissions and low power output and could also possibly damage the engine and cause extra wear and tear on it.
This is the link to where I read that information.
http://neptune.spacebears.com/cars/stories/stat.html
This is the link to where I read that information.
http://neptune.spacebears.com/cars/stories/stat.html
Fleet Mechanic
Joined: Aug 2000
Posts: 1,504
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From: Texas
Low Engine Temperature
True, with the computerized fuel injection setups, the engines have to run at a certain temp range to get the proper economy, and performance. I had trouble with my 88, and I thought the guy at the parts house gave me a 180 degree thermo, but turned out to be a bad 195 thermo. It was staying too cool and wasn't getting into the operating band just right. Now it does though.
1988 F-150, SWB, 5.0 EFI (formerly 4.9 EFI), M5OD 5 speed, 3.08 gears, Summit shorty truck headers, Custom built Flowmaster exhaust system. Force 4 LP6000 lightbar, Federal signal PA-300 100 watt siren, Icom IC-V100 50 watt mobile radio.
=======================================
1965 F-100 (just purchased 1/18/01), SWB, 390, C-6 auto. Dual exhaust, Not much else to do to it.
Can see both below.
[link:www.geocities.com/hotrodford_88/|Hotrodford_88's Webpage]
1988 F-150, SWB, 5.0 EFI (formerly 4.9 EFI), M5OD 5 speed, 3.08 gears, Summit shorty truck headers, Custom built Flowmaster exhaust system. Force 4 LP6000 lightbar, Federal signal PA-300 100 watt siren, Icom IC-V100 50 watt mobile radio.
=======================================
1965 F-100 (just purchased 1/18/01), SWB, 390, C-6 auto. Dual exhaust, Not much else to do to it.
Can see both below.
[link:www.geocities.com/hotrodford_88/|Hotrodford_88's Webpage]
Senior User
Joined: Aug 1999
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Low Engine Temperature
My 2 cents.
First inclination is stuck open tstadt. You verified that they open correct, so that's good.
Next might be to doubt the mechanical thermometer you checked with. I would double-check its accuracy.
Finally, if the engine was really running at 150deg like you say, the engine would run rich and your gas mileage would be in the 10-11 range. Also the idle would be high, like 1200 or more.
I am really doubting your temp gauge.
Randy
First inclination is stuck open tstadt. You verified that they open correct, so that's good.
Next might be to doubt the mechanical thermometer you checked with. I would double-check its accuracy.
Finally, if the engine was really running at 150deg like you say, the engine would run rich and your gas mileage would be in the 10-11 range. Also the idle would be high, like 1200 or more.
I am really doubting your temp gauge.
Randy
Tuned
Joined: Nov 2000
Posts: 426
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From: houston, texas (now Berli
Low Engine Temperature
Let us all know if you find out what it was! My gauge also reads all the way to the left part of the normal range (it starts off in the cold range then comes up about one third of the way to the 'N' in Normal and then goes back to stay at the left border to cold).
=========================
1988 F-150, V8, 5.0L (302ci), 5spd, SuperCab. Shorty headers, K&N filter, MSD 6a ignition, Accell 300 8.8mm race wires, Accell supercoil, Accell rotor+cap, Bosch +4 Platinum plugs, RanchHand bumper. Soon: Dual exhaust.
http://brembs.net/cars/FordPU.html
=========================
1988 F-150, V8, 5.0L (302ci), 5spd, SuperCab. Shorty headers, K&N filter, MSD 6a ignition, Accell 300 8.8mm race wires, Accell supercoil, Accell rotor+cap, Bosch +4 Platinum plugs, RanchHand bumper. Soon: Dual exhaust.
http://brembs.net/cars/FordPU.html
Senior User
Joined: Jan 2000
Posts: 242
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From: St. Paul, MN
Low Engine Temperature
Check the fan clutch to make sure it isn't seized up and causing the fan to turn all the time. There should be some drag but not a lot when turning the fan by hand with the engine off.
Dustin Siebert
mrlaserboy(No Email Addresses In Posts!)
Registry: http://www.superford.org/cgi-bin/sf.cgi?uid=default&vr2=1&ID=201
Home Page: http://www.superford.org/users/ylobronc/index.html
'88 Bronco XLT 302EFI/AOD/BW1356/44IFS with 8 lugs(open)/10.25 FF(Lockright locker)/4.56/6" Superlift/2" BL/35's-street/38.5's-trails
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Dustin Siebert
mrlaserboy(No Email Addresses In Posts!)
Registry: http://www.superford.org/cgi-bin/sf.cgi?uid=default&vr2=1&ID=201
Home Page: http://www.superford.org/users/ylobronc/index.html
'88 Bronco XLT 302EFI/AOD/BW1356/44IFS with 8 lugs(open)/10.25 FF(Lockright locker)/4.56/6" Superlift/2" BL/35's-street/38.5's-trails
2 BIG BRONCOS 4X4 CLUB - GREAT LAKES CHAPTER http://www.2bigbroncos.org
Posting Guru
Joined: Jun 1999
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From: Durham
Low Engine Temperature
Yeah, it's at least a good problem to have. Most people chase overheating problems. You might want to try covering all or part of the outside of your radiator to restrict air flow. That should warm it up. What was the outside temp with your cool running engine?
'82 F150 2WD w/351W (orig 300 I6)
Slik
'82 F150 2WD w/351W (orig 300 I6)
Slik