Hello all in the Superduty section of FTE. Some of you might know me from the IDI section of this site. What a great place to find any info on Ford trucks. Here is my dilemma now,lol. My boss bought a 99 F-250 Superduty with the V10. It was over heating a little when he 1st got it. I replaced the t-stat, and it seemed to stop overheating. It would only got hot when towing the stump grinder, or towing nothing, but with the AC on. I have seen some other post in this section on gauges reading falsely, but that is not the issue here. It seemed fine for awhile, even drove it to upstate NY,10 hrs away, no problem. Drove it a week up there, no problem. Coming home on the jersey turnpike, she ran hot. got it cooled down, drove for a bit, hot again. Did this 3-4 times, then never ran hot the rest of the way home. We got back and put a new fan clutch on it, another t-stat, flushed it and still overheats. When it gets hot, the plastic resevior tank looks like it wants to explode, with so much pressue in it. Any ideas?
PS> I guess these motors are prone to exhaust bolt problems, ours have 8 of the 20 gone.

 

How many miles it had on it?

Does it puke coolant if you drive REALLY HARD like bad driver that rev to 6K rpm and slam brake.

It sound like head gasket issues but keep update on us.

 

We dont drive it hard, doubt head gasket issues because there is no oil/coolant mixing anywhere. Nor does it blow any white smoke, actually doesnt smoke at all. The truck has 172k on it. It doesnt do it steadily, more of a sporadic problem. It seems to get hot if we drive it on the highway, around town it isnt bad. That is why I replaced the fan clutch on it. I am going to flush the engine tomorrow and see if any junk comes out of it. Truck has lots of power, just cant keep it cool.

 

Can you pull that black plastic between grill to hood latch? Try look though that do you see radiator clean or it clogged with dirty or bugs dent tons fins on radiator?

 

When he 1st got the truck, the radiator had some fins that were bent over. I didnt have a radiator comb, so I sat there for 2 hrs with a jewelers screwdriver and bent them back straight. Talk about a tedious job, especially for someone with no paitence,lol!! ME!!

 

It done time for new radiator. My old 01 F250 5.4L had those thousands of smash fins it wasn't worth to fix. End replace new radiator.

 

For the record, the cooling system in these is VERY adequate. If everything is right, it is very, very difficult to get them hot! One of the things I love the most about these rigs. I tow on 110 degree days, on steep grades and low speeds and she stays cooler than any other vehicle I have ever seen.

So something is amiss....
Most common causes:
1) Too much heat being generated
2) Insufficient cooling capacity
3) Insufficient flow

1) Tiny head gasket problem or crack in metal. Keep in mind that combustion pressures are MUCH higher than coolant pressure. Exhaust gasses can push into coolant passage without coolant getting back through the same failure.
Ways to detect: In most vehicles, you can look for bubbles in coolant when cap is off. But with no cap in radiator, hard on these. There are test strips available at good auto parts stores that you can dip into coolant and they will indicate is exhaust gasses are getting into coolant.

2) Sounds like air can get through radiator due to your efforts. But how many COOLANT passages are plugged up and not doing anything? If the PO was not flushing the coolant on regular basis, it could be very plugged up at 12+ years. I replaced my radiator soon after purchase as the PO could not remember the last time (if ever) he had changed it. $250 for new. Secondary bonus: New radiator had trans cooler in it. The 99's originally did NOT have trans cooler in radiator. Plumbing it in gives the tranny an easier life. Tertiary bonus: Plastic tanks in radiator start failing after 10+ years anyway.... Changing now could prevent traumatic failure...

3) Water pump or plugged passages.

 

Thank guys for all the tips on where to look for problems on this. It will have to get put aside for a couple of days,just because when my boss was backing in the grapple truck last night, it blew a wheel cylinder. Just got that tore down, and it seems one of the adjusters stopped working, so s**t fell apart. I will let ya all know when I'm back on the v-10.

 

I would change the hoses, too.

 

Goodmorning all. Now that I have a moment, just wanted to let everyone know that the radiator was the issue on our v-10. took it to have it dipped, and the shop said it was just about plugged tight. I put a new radiator in, and it runs fine now. Now its time to fix all the broken exhaust manifold studs/bolts. Thanx again for all the tip guys, what a great site.