Overheating
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Post Fiend
Joined: Mar 2011
Posts: 8,501
Likes: 4
From: Lynchburg, VA
Overheating
I noticed the other day that the upper radiator hose was swollen. It's seemed lately that the engine was a little hotter to the touch than normal, but it's also been a while since the weather has been warm.
I checked around the thermostat housing and water pump with a IR thermometer and found a few spots reaching 212. This was after a 3 mile drive in city traffic. I had to be somewhere so I dialed back the timing a little and drove. I stopped after about 5 miles and checked the temperature again. 225 was the highest I saw. Drove to where I needed to be and drove home without a problem. Radiator temperature lowers as and you move down the radiator. Only change to the truck lately has been a new Holley 4bbl. Running 67's IIRC. Plugs look fine. Timing had been set at 10*, moved it back to around 7*. EGR and all emissions stuff intact.
What should I start looking at? I have absolutely no clue at this point. I need to change the coolant, but I have no idea what to do with the old stuff, and I don't really want a place in the yard that grass won't grow. Thanks in advance
I checked around the thermostat housing and water pump with a IR thermometer and found a few spots reaching 212. This was after a 3 mile drive in city traffic. I had to be somewhere so I dialed back the timing a little and drove. I stopped after about 5 miles and checked the temperature again. 225 was the highest I saw. Drove to where I needed to be and drove home without a problem. Radiator temperature lowers as and you move down the radiator. Only change to the truck lately has been a new Holley 4bbl. Running 67's IIRC. Plugs look fine. Timing had been set at 10*, moved it back to around 7*. EGR and all emissions stuff intact.
What should I start looking at? I have absolutely no clue at this point. I need to change the coolant, but I have no idea what to do with the old stuff, and I don't really want a place in the yard that grass won't grow. Thanks in advance
Rusty Roller
Joined: Oct 2011
Posts: 1,423
Likes: 5
From: Santa Cruz Mountains
How long has it been since you changed that hose? The pressure cap should release before expanding a radiator hose.
If the thermostat is failing it would allow much higher temps.
I would back flush the system replace the thermostat, coolant and probably replace the hoses and cap too. Might as well be ready for the summer season....
.
If the thermostat is failing it would allow much higher temps.
I would back flush the system replace the thermostat, coolant and probably replace the hoses and cap too. Might as well be ready for the summer season....
.
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Post Fiend
Joined: Mar 2011
Posts: 8,501
Likes: 4
From: Lynchburg, VA
I haven't touched the cooling system since I got the truck a year ago. Replaced the cap just a week or two ago. Guess I'll go ahead and replace the hoses and thermostat. I know the thermo for the 351m is a bit different. Where can I find the correct one?
Rusty Roller
Joined: Oct 2011
Posts: 1,423
Likes: 5
From: Santa Cruz Mountains
I don't know what is different with the 351m but I looked up your model at O'Reillys and found these.
1) Motorcraft: Motorcraft RT1139 - Thermostats | O'Reilly Auto Parts
2) Murray fail-safe: Murray Caps & Stats 7200-195 - Fail-Safe Thermostat | O'Reilly Auto Parts
https://www.ford-trucks.com/forums/9...hermostat.html
.
1) Motorcraft: Motorcraft RT1139 - Thermostats | O'Reilly Auto Parts
2) Murray fail-safe: Murray Caps & Stats 7200-195 - Fail-Safe Thermostat | O'Reilly Auto Parts
https://www.ford-trucks.com/forums/9...hermostat.html
.
Postmaster
Joined: Nov 2011
Posts: 2,553
Likes: 10
Agree new hoses, flush and stat are in order.
A comment on timing... advance helps the engine run more efficiently and cooler. Usually retarding timing increases heat. Suggest you put the timing where it runs best.
Another... IR guns are not always consistent. I'd go by the guage. If you don't trust the guage, get an aftermarket. Some heat up after shutdown is normal... it just shouldn't be too hot while running. Under 200 is great. 200 - 210 is OK. 210-220 is getting warm, 220-230 I'd start getting worried and over 230 she's hot. With anti-freeze and a pressure cap it won't boil until 250+.
A comment on timing... advance helps the engine run more efficiently and cooler. Usually retarding timing increases heat. Suggest you put the timing where it runs best.
Another... IR guns are not always consistent. I'd go by the guage. If you don't trust the guage, get an aftermarket. Some heat up after shutdown is normal... it just shouldn't be too hot while running. Under 200 is great. 200 - 210 is OK. 210-220 is getting warm, 220-230 I'd start getting worried and over 230 she's hot. With anti-freeze and a pressure cap it won't boil until 250+.
Thread Starter
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Post Fiend
Joined: Mar 2011
Posts: 8,501
Likes: 4
From: Lynchburg, VA
I don't know what is different with the 351m but I looked up your model at O'Reillys and found these.
1) Motorcraft: Motorcraft RT1139 - Thermostats | O'Reilly Auto Parts
2) Murray fail-safe: Murray Caps & Stats 7200-195 - Fail-Safe Thermostat | O'Reilly Auto Parts
https://www.ford-trucks.com/forums/9...hermostat.html
.
1) Motorcraft: Motorcraft RT1139 - Thermostats | O'Reilly Auto Parts
2) Murray fail-safe: Murray Caps & Stats 7200-195 - Fail-Safe Thermostat | O'Reilly Auto Parts
https://www.ford-trucks.com/forums/9...hermostat.html
.
I think the part on the bottom is what seals it off.
Agree new hoses, flush and stat are in order.
A comment on timing... advance helps the engine run more efficiently and cooler. Usually retarding timing increases heat. Suggest you put the timing where it runs best.
Another... IR guns are not always consistent. I'd go by the guage. If you don't trust the guage, get an aftermarket. Some heat up after shutdown is normal... it just shouldn't be too hot while running. Under 200 is great. 200 - 210 is OK. 210-220 is getting warm, 220-230 I'd start getting worried and over 230 she's hot. With anti-freeze and a pressure cap it won't boil until 250+.
A comment on timing... advance helps the engine run more efficiently and cooler. Usually retarding timing increases heat. Suggest you put the timing where it runs best.
Another... IR guns are not always consistent. I'd go by the guage. If you don't trust the guage, get an aftermarket. Some heat up after shutdown is normal... it just shouldn't be too hot while running. Under 200 is great. 200 - 210 is OK. 210-220 is getting warm, 220-230 I'd start getting worried and over 230 she's hot. With anti-freeze and a pressure cap it won't boil until 250+.
I had questioned the accuracy of this thermometer, but it's been fairly accurate for other things. I don't remember the engine be quite this hot last summer, either. I do need to get an aftermarket set of gauges.
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