my truck is having the weirdest problem .its a 2000 with 140,000 on the ticker and shows the tempature gauge getting hot really fast when i drive over 65 mph on a hot day.if i let off the gas it cools back down although not as fast as it goes up.i have changed the thermostat and flushed the radiator to no avail.i cant run the air as it makes the motor lug down a lot more than it ever did but this problem happens every day without air after it gets up over 85 degrees and i hit the freeway going back across town .i have to take it out of gear[manual] while going down hill to get it to cool down.any suggestions for me to look at as this does not happen early in the morning when its a little cooler outside

 

I'm betting radiator.
https://www.ford-trucks.com/forums/s...d.php?t=231479

 

Yep, most definitely the radiator. Brian and myself experienced the EXACT problem last year at the same time. The fix was the same. I bought a new radiator for 161.00, he had his removed and flushed. Home flushing will not do it. I replaced the thermostat, hoses ,water pump, cap and home flushed the old one three times. The new one did the trick. Brian had his professionally removed,flushed (rotted out) and his works fine.

 

wonder why this only happens to the radiator when ambient temp is over 85 degrees outside , today was overcast and around 80 degrees and it was fine for the first time in a while. just weird that that few a degrees of tempature makes it overheat

 

I have a 2000 F150 with the 4.2 and I am having an overheating problem. I recently replaced the thermostat and I have always replaced the coolant twice a year. I notice while I am driving around 70 or I am in stop and go traffic, the temperature gauge shoots up. I turn on my heater and the new termostat opens and the engine starts cooling.

Did anyone replace the "coolant temperature sending unit" ?

Thanks,

Jim Page

 

It's not that, and yes a few degrees does make a difference. Bite the bullet, either have it boiled out, or replaced, and you will have solved your problem. I also replaced my belt, and the fan clutch . I spent over $400 chasing this same problem, and I asked some of the same questions you are asking. Save yourself some time, money, and grief, and fix the radiator. I don't want anyone making my mistakes, I make 'em just fine.

 

Cool ... thanks travlnman !

 

I agree with Thomas. Save yourself the ha$$le.
Let our wasted efforts save you form doing the same.

 

changed the radiator saturday and all is well so far .that radiator is very easy to change.thanx so much for the help

 

I had this problem, it was the fan clutch that was bad. I check it by spinning the fan when the engine is cool. It should spin with a little drag. Then I ran everything during a hot day, stop the truck when it got hot, waited a few minutes then spin the fan again, it spin the same way, Fan Clutch was bad.

Mike
San Diego

 

Thanks for all the information ... I will have my radiator serviced this saturday and will check my fan clutch, after work this week also.

I appreciate everyone sharing thier pain with me !!!

Jim

 

Are you losing coolant?

 

...Welcome sginther to Ford Truck Enthusiasts! Please read the Guidelines, it will help you to navigate through and understand this site.

That has got to be the shortest first post ever!!!
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Yeah, I guess it was short. I am the owner of a 1998 F-150 XL with the infamous 4.2L V-6 engine. I have been doing a TON of research on this engine due to the fact that mine bent a rod a few weeks ago. I thought it was my fault. Come to find out that it is a defective gasket that has plagued thousands of people. But I think the problem is that most people like me saw strange things happen (like coolant level disappearing and heat rising) and asked peoples opinions and was satisfied with the answers.

A few weeks before she died, I started noticing the temperature rise and fall. I asked a mechanic about it and he told me that I might be losing coolant or that the thermostat was faulty and only worked some of the time. He told me to check it while I drove and make sure it never gets into the red. I started looking at my coolant and lo and behold, I was losing some. I pointed out to the same mechanic that I never found any puddles after I parked it. He told me that I probably lost it during driving and that that could be the sign of a water pump going bad. I never "red-lined" it. It would go from it's normal position up toward the "H" and back down again. I usually noticed this during particularly hot days. Living in South Alabama you would think they are all hot. 80 degrees and she was fine. Upwards to 90 and it would rise and fall - just like stelectric mentioned. I was also told to check the oil for milk. No milk. Therfore I was told that I needed to keep a bottle of water with me if the coolant dropped too low. I might also have a small leak in a hose somewhere. I kept looking under the truck to see signs of leaks but never did. The problem is that it was none of it. I spent a few weeks trying to figure out what the problem was rather than taking it to someone to fix. But with all the various things I heard, there is no guarantee that it would have gotten fixed.

In fact, the day before I noticed my starter giving me a little scrathing noise at the end of cranking the truck. During the initial crank (at the end right as the engine engaged) it sounded like I tried to turn the key while the engine is running. I also checked on that and was told that my starter might be going. Sad thing is that many people replace their starter, only to find that day, the next day or the day after that the starter was fine. They now had a blown engine.

Long story even longer... The gasket thing. It allowed too much coolant into the cylinders. I cranked it up one night to head home and the hydrolock (the starter "problem" I thought I had) occured and bent a rod. I guess being of limited financial resources, I preferred to figure out what the problem was and then have it fixed. All of the things mentioned can be serious things, but are things that develop over time. The gasket thing does the same but bites you so quick. Without seeing the signs, so many people (mechanics included) are fooled and diagnose the wrong thing.

Doing all of this research I feel so badly for people who, like me, love their trucks but are disgusted to know that it was not our fault. Nobody fixed it, nobody told me about it. In fact I had all of the diagnoses I needed. But nothing prepared me for a blown engine. Someone could have made an effort to let me know that the gasket design was flawed. I would have paid the $300-500 for a gasket replacement - instead I am having to foot a $4K bill. It just dosen't seem fair.

So back to my first post for stelectric - I AM NOT A MECHANIC, BUT I HAVE BEEN BURNED BY THE SAME THING IT APPEARS YOU HAVE EXPERIENCED. I hope indeed that it is just your radiator. But there are so many people out there like me that I hate to see any one else "join the club".

Again, sorry for the first short post, but maybe this one made up for it!!

If I have saved anyone from this problem, please let me know that my pain might be your gain. E-mail me at seginther@aol.com. If you have been bitten by the Ford bug, also e-mail me. I am keeping a list of e-mail addresses of people like me with this problem. So far I have about 200 e-mail addresses. Never know what I might do with that kind of fire power.

Thanks, and again, let me know!!! Good luck to all of you.

 

does anyone know if there is a relay for the fan and where would it be. I checked my book there is nothing in there. thank you