last week, hauling boat to lake, was running a little hotter than normal after 1/2 hr drive. All of a sudden temp climbs fast, pull over and find a 3/8" hose near throttle sensor burst. Replaced hose and refilled with water. Finished drive to lake. Drove 30 mile back home and to work next day with no problem. Drove about 30 miles and it started pucking water from overflow tank. refilled and drove home after cool down. Changed the thermostat and replaced with new antifreeze mixture Ran for a week with no problems. Power seems to be a little low with occasional hesitation when accelerating. Went on longer trip 30 miles and got hot again with a little coolant lose. Does his sound like a head gasket issue, oil looks great, just changed it last week with no abnormal issues in oil. If it is head gasket, how do you check this? 87 f-150, fi 8 cyl, 5.0 175k miles. thanks

 

A pinhole leak is all it takes. Cap pressure good, including seal? Fan clutch?

 

I have this same problem

It cool fine but when you turn off it swollen so bad that you can't ever touch radiator hose and it feel like solid instead soft. I was afraid if I try squeeze maybe it would pop and squirt HOT coolant at me.

It only 18k miles on 351W.


Put AC fan clutch make huge improve when it idle it keep radiator very cool but disadvantage when you turn off it get HOT.

 

Put a pressure tester on it & see if it holds pressure & see if there are any leaks ...Lew

 

if you pull the plugs and see that one is wet or really clean that might be the cylinder that is leaking at the head gasket. and do a compression test.

 

Something to try if the other stuff doesn't pan out. Remove the cap & start the engine. Allow to idle & reach norm. op. temp.. Add/ top off coolant as needed during this process.
It's called "burping" your coolant system. Heater temp setting on high.

 

Interested I decided give 1 chance. I am not sure but I think it work.

So much air pop radiator cap when I try open with welder glove.

Then left idle 10 mins. Notice lot bubble out it. Then it drop to below then bam explosive coolant out radiator.

 

You could be a different story. The other guy replaced his thermostat after overheating. I suggest you do the same if you have drastically overheated recently, as it pooches the thermostat & they many times don't function correctly after that.

 

Water pump? Over pressurizing system, poped hose off, puking out fluid, then becoming air bound w/ hot spots. Water pump.

 

It never get overheat enough. Radiator is cool you could touch without get burn.

Once you turn off then couple min then Radiator get real HOT to touch.


That one reason why I keep eye on radiator because most time 351W in truck don't last long because coolant leak while you drive. I know 3 friends with that issues so it burned engine.

 

I did the burping of the system and it did seem to fix the problem of overheating. New thermostat and hoses should have complete system keeping it cool. Thanks for the advice all of you.

 

So its not too hot to touch when running? Only when you turn the truck off it gets too hot to touch?

 

For a week after burping system it has been fine. Local weather has been cool until yesterday. Driving about 30 miles it kept getting hotter and hotter the more I drove. I drove it pretty easy, average about 45mph. When i stopped it started overflowing fluid until it cooled, lost about a gallon. I am thinking the radiator might be plugged. About a month ago I filled the radiator with some head gasket stop leak, I wasnt sure if the head gasket was going bad as it was missing occasionally when it was either cold or under a load, could this be what is causing the overheating problem. I've read that this stuff can mess up a radiator by plugging it up. If so can you drain and clean out the radiator with a flush or do I need a new radiator? Thanks for any help you guys can give me!

 

Yes

It not too hot to touch radiator it feel like cooler when it turn off 2 min it really hot to touch.

 

If its not circulating & the thermostate is open & the water pump is ok then the rad may be pluged up , did you replace the cap ?? How hot does it get when it overflows ?? You can take the radiator to a rad shop & have it roded out & cleaned or replace it .....Lew