Overheating
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Junior Member
Joined: Jul 2009
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Overheating
So I have a 1988 4x4 f-150 Lariat Single Cab long Bed pickup. It has a 302W.
A little History:
The truck and transmission (manual) has ~240,000mi while the Engine and transfer case have ~80,000mi and ~90,000mi respectively. This is a beautiful truck blue and silver, shiny chrome, no rips or tears in the seats or dash. The previous owner (original owner I believe) took meticulous care of it and documented all service.
I have had nothing but trouble with this truck.
I’ve dumped near $2k in parts into it since I bought it. All new power steering, pump, gearbox, hoses. New wheel bearings - Break rotors and pads, wheel studs - Spark plugs, wires, distributor, coil pack - a bunch of other little odds and ends.
Every time I fix something, something else breaks.
The (Current) Problem... From the beginning:
The truck never really ran right, though it has always run. It seems a bit down on power. If I put it in first and punch it (not pop clutch) it won’t even chirp the rear wheels. It idles rough (almost dies ~5-600 rpm) once it warms up.
The temp gauge on the dash never worked and I blew a radiator hose so I went and bought both temp sending units (the one for the gauge and the one for the ECM), a new hose and a thermostat. Replaced all of it and took it out for a test drive. I hadn't driven 10 minutes when the water pump blew out. So I took her home and let her sit for a few months ("that will teach her," I thought).
Once I decided that was enough punishment I bought a new water pump (the heavy duty model $100) and all new hoses, save the one I replaced previously. I installed them.
I asked the auto-parts store what the capacity of the cooling system was, they said 1 7/8 gal or some such number (under 2 gal) I poured nearly two gallons into the radiator and figured I would be good to go and I would top it off after a short drive.
I cranked 'er up and did a quick leak check. Everything looked good so I went for a drive. Before I got out of the neighborhood the RED engine light came on and the temp was in the red. So I turned her off, let her cool a few minutes, and limped back home.
I flipped the pressure release on the radiator cap and it blew bubbles into my overflow tank. "Ok, so it didn’t have enough coolant," I thought. I poured nearly another full gallon into it. "Those Idiots at Advanced," I thought. I even burped the upper radiator hose.
Coolant and Confidence both refilled, I started her up and after another quick leak check, went out for another spin.
Again, shortly after pulling out of the neighborhood engine light and temp in the red. AAAHHHHHH!!!!!! On the way back home I noticed that if I only barely tough the throttle the temp will stay right in the middle of the normal range. Right on the r or m in normal. When I touch the gas the temp sky rockets going from normal to engine light in a matter of seconds. Then if I let off it will come back down, to normal, nearly as quickly.
When I got her back home I let her idle a little bit. Temp is fine. Hold the rpm's at 2500 and within a few seconds the needle takes back off, running for red. Let off, it cools back to normal.
Observations and what I've checked:
-Truck idles fine when the temp is normal.
-Idles very rough when hot. No oil pressure, tries to stall engine light is on.
-Probably running hot for quite a while but I didn’t know b/c no temp gauge.
-Cooling system is now full. Water is in the heater core (highest point in cooling system)
-Coolant looks clean. No leaks in cooling system.
-Oil looks normal (Needs to be changed maybe a quart low)
-Motor still a little warm, if I start the motor with the radiator cap off the coolant will slowly climb the tube. Takes two or three minutes to go from the top of radiator cavity (bottom of filler tube) to overflowing. Was told this could mean blown head gasket.
-Fan turning correct direction, Serpentine belt installed correctly.
-Fan clutch appears to operate normally, accelerates with motor.
-Thermostat appears to be working. Top and bottom radiator hoses both get hot but it takes them a while after the heater core hoses heat up.
-Thermostat fails in open position.
I am completely stumped on this. When I get home I am going to warm the motor up and spray some overflow into a glass jar. I was told if there is oil in the coolant it will rise to the top as it cools. I’m also going to check the oil for water as well. (Signs of a blown head gasket)
Does this sound like a blown head gasket? I’m hoping that it is not. I don’t know what else to do. Any suggestions would be greatly appreciated.
HELP!!!!
A little History:
The truck and transmission (manual) has ~240,000mi while the Engine and transfer case have ~80,000mi and ~90,000mi respectively. This is a beautiful truck blue and silver, shiny chrome, no rips or tears in the seats or dash. The previous owner (original owner I believe) took meticulous care of it and documented all service.
I have had nothing but trouble with this truck.
I’ve dumped near $2k in parts into it since I bought it. All new power steering, pump, gearbox, hoses. New wheel bearings - Break rotors and pads, wheel studs - Spark plugs, wires, distributor, coil pack - a bunch of other little odds and ends.
Every time I fix something, something else breaks.
The (Current) Problem... From the beginning:
The truck never really ran right, though it has always run. It seems a bit down on power. If I put it in first and punch it (not pop clutch) it won’t even chirp the rear wheels. It idles rough (almost dies ~5-600 rpm) once it warms up.
The temp gauge on the dash never worked and I blew a radiator hose so I went and bought both temp sending units (the one for the gauge and the one for the ECM), a new hose and a thermostat. Replaced all of it and took it out for a test drive. I hadn't driven 10 minutes when the water pump blew out. So I took her home and let her sit for a few months ("that will teach her," I thought).
Once I decided that was enough punishment I bought a new water pump (the heavy duty model $100) and all new hoses, save the one I replaced previously. I installed them.
I asked the auto-parts store what the capacity of the cooling system was, they said 1 7/8 gal or some such number (under 2 gal) I poured nearly two gallons into the radiator and figured I would be good to go and I would top it off after a short drive.
I cranked 'er up and did a quick leak check. Everything looked good so I went for a drive. Before I got out of the neighborhood the RED engine light came on and the temp was in the red. So I turned her off, let her cool a few minutes, and limped back home.
I flipped the pressure release on the radiator cap and it blew bubbles into my overflow tank. "Ok, so it didn’t have enough coolant," I thought. I poured nearly another full gallon into it. "Those Idiots at Advanced," I thought. I even burped the upper radiator hose.
Coolant and Confidence both refilled, I started her up and after another quick leak check, went out for another spin.
Again, shortly after pulling out of the neighborhood engine light and temp in the red. AAAHHHHHH!!!!!! On the way back home I noticed that if I only barely tough the throttle the temp will stay right in the middle of the normal range. Right on the r or m in normal. When I touch the gas the temp sky rockets going from normal to engine light in a matter of seconds. Then if I let off it will come back down, to normal, nearly as quickly.
When I got her back home I let her idle a little bit. Temp is fine. Hold the rpm's at 2500 and within a few seconds the needle takes back off, running for red. Let off, it cools back to normal.
Observations and what I've checked:
-Truck idles fine when the temp is normal.
-Idles very rough when hot. No oil pressure, tries to stall engine light is on.
-Probably running hot for quite a while but I didn’t know b/c no temp gauge.
-Cooling system is now full. Water is in the heater core (highest point in cooling system)
-Coolant looks clean. No leaks in cooling system.
-Oil looks normal (Needs to be changed maybe a quart low)
-Motor still a little warm, if I start the motor with the radiator cap off the coolant will slowly climb the tube. Takes two or three minutes to go from the top of radiator cavity (bottom of filler tube) to overflowing. Was told this could mean blown head gasket.
-Fan turning correct direction, Serpentine belt installed correctly.
-Fan clutch appears to operate normally, accelerates with motor.
-Thermostat appears to be working. Top and bottom radiator hoses both get hot but it takes them a while after the heater core hoses heat up.
-Thermostat fails in open position.
I am completely stumped on this. When I get home I am going to warm the motor up and spray some overflow into a glass jar. I was told if there is oil in the coolant it will rise to the top as it cools. I’m also going to check the oil for water as well. (Signs of a blown head gasket)
Does this sound like a blown head gasket? I’m hoping that it is not. I don’t know what else to do. Any suggestions would be greatly appreciated.
HELP!!!!
Senior Member
Joined: May 2010
Posts: 598
Likes: 12
usually with a blown head gasket you will have white smoke coming out of the exhaust. Another sign would be extreme pressure buildup and coolant will dump out of the overflow. The only way to know for sure if it's the HG is to perform a leak down test or compression test. Low compression numbers means that you have a blown headgasket. Even if the HG is blown, you may or may not see water in the oil/white smoke. A compression tester is cheap and easy to do, so I would start there.
Senior Member
Joined: Jul 2007
Posts: 3,805
Likes: 480
From: Cape Girardeau MO
The 1988 302 was rated for 185hp at 3800 rpm. Can't say I've ever barked my tires either. Also can't speak to the rating of your newer motor.
The cooling system capacity is listed at 13 quart w/o AC, 15 quart w/ AC, and 14 quart with Super Cooling - whatever that is.
Blowing a hose followed by blowing a water pump seal has me wondering whether the radiator cap is relieving as it should. Not a fan of the flip-lever radiator caps.
The temperature 'skyrocketing' is just about physically impossible, IMO. Wondering if your charging system isn't going nuts? Another thought is the radiator core being plugged, restricting flow and heat transfer.
Sounds like you've got a real headscratcher. Good luck, and keep us posted.
The cooling system capacity is listed at 13 quart w/o AC, 15 quart w/ AC, and 14 quart with Super Cooling - whatever that is.
Blowing a hose followed by blowing a water pump seal has me wondering whether the radiator cap is relieving as it should. Not a fan of the flip-lever radiator caps.
The temperature 'skyrocketing' is just about physically impossible, IMO. Wondering if your charging system isn't going nuts? Another thought is the radiator core being plugged, restricting flow and heat transfer.
Sounds like you've got a real headscratcher. Good luck, and keep us posted.
Senior Member
Joined: May 2010
Posts: 598
Likes: 12
To the poster- DO NOT drive the car or even start it up until you have had a compression test done.
5 Year Member
Joined: Nov 2009
Posts: 936
Likes: 10
From: Maryland
Pull the thermostat out completely and run it for a bit. I've bought BRAND NEW thermostats that were bad and a member on here has mentioned that a bad thermostat actually damaged their radiator. Those pesky little buggers can wreak havoc.
If it runs normal and doesn't over heat, there's your problem and Bob's your Uncle.
If it runs normal and doesn't over heat, there's your problem and Bob's your Uncle.
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Hi-Rev Motorsports
Joined: Aug 2009
Posts: 4,898
Likes: 65
From: Northern Indiana
sure you didnt put the thermostat in backwards...?
its either that or the radiator is plugged....
heating up that quick is a blockage...either rad or t-stat...the spring part goes inside the engine...
its either that or the radiator is plugged....
heating up that quick is a blockage...either rad or t-stat...the spring part goes inside the engine...
Senior Member
Joined: May 2010
Posts: 151
Likes: 0
From: kerrlake
ive seen a cracked head on a valve port near water jacket do as you are sayying pressurize radiator before and it will swell hose twice thier size new... get a mech temp gauge see if temp is that high and i hope im wrong ...
