Puke

Over the last 10 years this has gotten worse and worse.
If I am going 70 mph, my truck's temperature is fine even if I'm going up a grade, etc., But when I am going 10 or 20 mpg and going up a grade (even if my truck is not pulling anything, etc.,) it runs awful warm,..and is getting worse. Yesterday I had to go about 3 miles up a fairly steep grade (1st or 2nd gear (automatic tran) and by the time I was done the temp was over half way between 190 and 240. Usually it just sit's there at around 192 degrees when I'm going faster.

Do I need a new radiator? or is there some other solution. I doubt it would have to do with my fan since it's just been sneaking up on mean the last few years. I'm getting that age where I don't have a lot of energy so would rather get some info. ahead of time.

About 25 years ago I had a radiator replaced in my 1 ton dodge 360 gasser (it was running warm all the time)..and the mechanic said this would fix it. I paid him to replace it...and after he had replaced it there was no change at all. So at this point,..I figure the best info. I can get is on DTR,..which has never steered me wrong in the many years I've belonged to this site.

Ok, If you have a solution,..chime in. If I need to replace my radiator,..chime in also.

Puke

And, one more question,..I have read somewhere that there is some kind of electronic clutch on the fan that locks the fan up when you are at low speeds. Is there a way for me to test this? Because it seems like on a hot summer day in a traffic jamb...it may get awfully warm also. (don't get too many traffic jams here..).

nkennedy

If it gets hot, and especially going up hills in the summer, you should hear the fan. It sounds like a Jet under the hood.

Puke

OK,
WHen I first start it in the morning I hear that jet sound. But I don't believe I hear it at all when I'm going up a hill slow and the motor is getting not.

Is this really electrical and not mechanical (the clutch that turns it on if it's hot?). I think back in the old days..I mean 35 years ago or more...they were all like...a limited slip type of thing. And I guess somewhere along the line they changed things and I missed the memo.?

Puke

I checked. I don't think it is electronic. There are no wires.
Also, it is fairly stiff to turn. Does not spin freely at all (at least sitting in the driveway not warmed up).
One more thing,....just looking at it..this fan is nothing to brag about,..I would think it would have thicker blades or something. I think the ones on my 1993 dodge diesel are better blades.

Puke

I just started the truck today (hadn't ran it yet...today)... I didn't hear it roar when I started it up.

Puke

I let it run 5 minutes and then shut it off. The fan was pretty easy to turn when I shut it off....but I don't know whether you would call it free wheeling or not... It was much easier to turn after running it for 5 minutes..than it was before I ran it for 5 minutes.

I also did the news paper test and it shredded the newspaper.

Then I went and found a grade (couldn't find a real steep one)..got it only about 200 degrees or a little more. Got out and checked the fan. It was stiffer to move than when the motor hadn't warmed up. So maybe that means I'm barking up the wrong tree. I don't know.

BarryG

I know on my 01 every 5 years or so I would have to clean the radiator. You need to be able to get to the front side of it. You will not be able to do a good job of cleaning it just from the back side and there is too much stuff in front of it to get it done. To do it right you either need to remove the stuff in front of it or pull it out. Spray with some degreaser let it sit and wash it off. Power washer works if used on very wide spray if careful. Also if it is out you could take it to a radiator shop and have them boil it etc which would get the inside and the outside.

A couple years ago I thought I needed to clean it again as it was starting to run a bit warmer. However within a couple weeks I noticed I had a leak. One of the seams on the end started to split. At first it was just a pressure leak I am guessing as it wasnt leaking but again within a couple weeks there was an obvious leak while running. I replaced it at that time 330 k on it.

You might also check the radiator cap.. If it is not holding pressure that would make it run a bit warmer.

My fan does not come on very often unless I am towing heavy, very long grade up a pass in the mountains etc and there is no mistaking it when it comes on as mentioned previously the jet engine noise starts and typically doesn't run that long at least on mine

Puke

I am going to get my pressure washer out.

Also, I haven't drained it for around ten years. (i drove it less and less when fuel got expensive....started driving my tiny ford ranger).

SIXSLUG

Could be worn water pump vanes, sticky thermostat, dirty radiator, old coolant, fan clutch, etc.

This can all be checked for free...

Even when around 100F my truck doesn't get much pass the middle of the gauge.

Puke

worn water pump vanes???? I was thinking they were stainless steel or something.

jrs_dodge_diesel

Is your breather bottle in the original location behind the fan?

If so, then the FRONT of your radiator may look like this:

Puke

Found at least 2 problems.
I pulled the radiator because there was a crack forming on the passenger side that was intermittently leaking. it's been that way for many years, but I had always thought that it was the drain valve not quite sealing....when I saw it was actually a microscopic crack that was doing that...I pulled it.

Also, the front of the radiator had quite a coat of greasy pollution on the front of it....it was in a circle...like you could see the footprint of the fan in the pollution...and....looking at it,...I am not surprised it was running warm. I doubt the crack had anything to do with it running warm.....I've been having to put a quart of antifreeze in it very couple months....for about ten years or longer. But I'm glad I saw the crack and decided to replace it.

OK,
So I am installing a new radiator from autozone in about ten minutes. I may attempt a flush on the heater core before I finish hooking everything back up. I made quite a mess....I think I only recovered about 2 1/2 gals of fluid,...fluid was a bit dirty. So I'll probably toss it.

Puke

MY RADIATOR LOOKED EXACTLY LIKE THAT ONE.

I have the new one in, but nothings hooked up yet. I was trying to figure out if I could backflush the heater and maybe the motor a bit....before hooking up the hoses and refilling with antifreeze

jrs_dodge_diesel

I would disconnect both hoses to the heater core, run your garden hose on one side of the heater core lines, and catch whatever comes out in a bucket on the other. That way it won't put any junk into the block. Blow out with compressed air after the water runs clear. Reconnect one hose and you can try to prefill the heater core and reconnect the second hose.

For filling the block this trick will make it easier, and minimize air pockets:

Make sure all hoses are connected. Open the thermostat housing, it's where the upper hose connects to the engine (3 bolts),and take out the thermostat. Be careful not to damage the gasket. Leave the radiator cap off. Fill up the block with your 50/50 water and coolant mix through the hole where the thermostat should be. Fill it up until the the water level is at the thermostat housing. Replace the thermostat, and put the housing back on, make sure to remember the gasket. Once that is reconnected, then top off the radiator. Replace the radiator cap, and fill the expansion tank to the COLD mark.

Drive it around, and let it warm up completely, and drive a little more so that the coolant can flow both in the block and the radiator. When done, check the expansion tank. If it is empty, fill it up to the COLD mark again, and drive it around some more. If there is some coolant left in the tank, fill it to the HOT level and you are done.

DO NOT DRIVE YOUR TRUCK WITHOUT A THERMOSTAT IN IT!

Don't be tempted to take out the thermostat. Without the thermostat, the coolant will not circulate correctly, and can lead to an overheat.

You should also relocate your breather bottle as well so your new radiator won't get clogged up too.