ranchertx

My 2001 24 Valve seems to run about 15-20 degrees above where it runs at hwy speed when I am driving slowly through the pasture.

I have replaced the thermostat.

Anyone run across this problem?

I am wondering if the radiator is plugged up, or possibly the water pump is not working right.

Dieselbuilder

check between your fan and ran to make sure its not soaked with oil from the crank case vent

ranchertx

Good idea, the puke bottle has thrown oil everywhere else, that may be the problem.

The old gal has 362,000 miles on her, so I dont worry about a little oil here and there, but I do worry about overheating.

johnh

you might also check the fan, it should have some resistance when turning by hand with the engine off

totalloser

Yeah, +1 I'm thinking that sounds like your fan clutch might be smoked. That much warmer it should lock up and cool things down regardless of the condition of the radiator-which can't hurt to be cleaned either way.

When you gun the engine while it's warm like that you should hear significant "whooshing" from the fan if the clutch is locking up at these higher temps.

ranchertx

I ran it up to about 180 degrees and shut the truck down, and the fan clutch still allowed it to be turned by hand.
Due to the high miles my mecahnic suggested we go ahead and replace the clutch, radiator, and water pump while we have everything apart. I think since the new radiator is about $290, may as well do it while we are working on it, in case that is part of the problem.
Al the mechanics locally tell me that none of the local radiator shops are worth a darn any more, and they all recommend replacing the radiator rather than flushing it.

totalloser

The fan clutch will NOT come on at 180. It's designed to come on above the temp that the stat runs. I don't know offhand what temp it kicks on, but were I to guess I'd guess more like 200 or 210.

Personally given the symptoms, I'd ONLY replace the fan clutch. Why replace good working parts? The fan clutch is pretty easy to do. Pulling the radiator is a pain due to the condenser, intercooler etc.

If you wind up having to replace the radiator anyway, there really isn't much more work if you do the fan clutch first.

BTW boiling and rodding radiators is rarely done anymore. Radiators aren't built in the same way they used to be. Most have plastic tanks and aluminum or brass cores which cannot be sweated apart and back together. Flushing is good to do when you do any cooling system service as it cleans out mineral deposits in the cooling system. Replacing the radiator doesn't do the same thing. A cooling system flush cleans out the engine and heater core as well.

A mechanic looking to make a buck might be more than happy to make extra bucks replacing good parts- beware of steel core radiators (GARBAGE imo).

ranchertx

My Mechanic called and said the clutch IS bad. Also, the water pump is original and has a lot of slack in it, the radiator needs replacing, as well as the lower radiator hose, and the belt tensioner.
He said I was lucky I didn't have some big problems. Given the miles and age of the truck, he said I have been lucky.
Well, this should fix me up for another 300,000 miles.

ranchertx

I got it out of the shop and what a difference it made. Between the bad fan clutch, and stopped up radiator, the truck was lucky to stay cool at all.
The AC even freezes you out now!