ok ive got a 93 f150 4x4 super cab 5.0 302, weve replaced the thermostat and water pump, but it still over heats on long runs. dont know what is causing it, earlier i flushed the radiator, so im hoping that it will work better, but if it doesnt, what could be causing it. i know i hooked the truck up to a hand held machine at o reilys and it said i had an egr valve issue or something like that, but i dont know what that is or if it would have anything to do with my cooling... ive been runnin water in it all summer, but dont think that should affect it that much, but ive also replaced the radiator cap. is there any reason that could be causing the truck to overheat, ive only seen it overheat mainly on long runs, from here to another town bout 20+ miles away. any ideas would be greatly appreciated im off tommora so id be able to check out some stuff on it...

 

At that age sounds like you need to have the radiator rodded. After you drive it for a while see if the top of the radiator is warmer than the bottom, that is where all the sludge collects. What happens is it cuts your cooling capacity in half, only half the radiator is doing it's job.

Get the water out and replace it with the proper mix of coolant. They call it coolant for a reason-it cools better than water. Also it has rust inhibitors in it. You have cast iron,brass, and aluminum in the motor and water will eat the metal.

Yes get the EGR issue taken care of, if not you can cause other damage.

 

ok thanks ill take a gander at er tomorrow, i just flushed er and put antifreeze back in er for winter 50/50... where is the egr valve at and would i have to take er to a shop to git her fixed?

 

How do you know? Have you checked with a thermometer, or are you just going by the dash gauge? Are there any secondary indications, like venting steam, knocking on acceleration, or melted parts? Read this caption:



Non-contact thermometers are getting cheap, like this (click it):

That's exceptionally BAD for everything. It causes FAST corrosion, radiator blockage, water pump failure, and LOTS more. Read this article.

A code whose definition mentions EGR doesn't mean there's anything wrong with the EGR valve. It has to be diagnosed, and the valve is the LEAST-likely cause for an EGR system code. Start by checking for vacuum leaks anywhere under the hood, including the HVAC system.

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The correct way to check is with a mechanic's stethoscope with the tip removed, or just a 3' piece of garden hose, with the engine idling. Listen for a distinct hiss. Puffing indicates an exhaust leak.

 

well, i could hear it bubblin and see water comin from the front end of the truck but i wasnt able to check, cause we were dumb asses but, i noticed some was comin out of the cap so thats why i replaced it, but lastnight i flushed the radiator and got a new cap, havent been able to try it out on the highway yet, will do that next payday, i get bout 4 miles to the gallon and wadnt able to afford it this payday but nextn ill see what she does... ive got 50/50 antifreeze in now. anyways imma hit the sack, ill post when i im out and about on the highway

 

[quote]i get bout 4 miles to the gallon[/qquote]

You have some major problems. Maybe you should get a mechanic that knows his *** from his elbow to look at it.

 

Boiling isn't the same as overheating, especially if you were running straight water with a bad cap. You MIGHT have overheated it, but nothing you've posted so far specifically indicates it.

 

Not to be a know it all ,but it sure sounds like a restricted flow of water. If it only overheats on a long drive then the radiator is probably the culprit. Remove the drain plug and if the water will not drain and is real rusty red or dark brown that normally means that the rad is stopped up. You can remove the t-stat an get some relief.

 

I have yet to of heard any mention to radiator hoses!!
Just finished replacing my fathers lower radiator hose due to over heating issues.. after doing all the needed testing I was able to diagnose the problem to a collapsing radiator hose on a long trip while this problem wouldn't happen on a local run, but would on a 60 mile trip it would happen!
After replacement of lower radiator hose and a flush and new 50/50 mix antifreeze installed all over-heating issues resolved!

Just a suggestion!

 

If you have a clutch type fan attached to the water pump it is probably slipping and little to no air is moving through the radiator(with a warm motor see it it spins freely,if so it's NFG). I took mine out and threw it away and put in a spacer and a flex fan, all my cooling problems went away.

 

That indicates severe restriction in the radiator.They're designed to slip, and no fan does anything when the vehicle is moving above ~40mph. This caption describes how to test a fan clutch: