I have a 2004.5 2500 with about 120,000 miles on it. Recently, at highway speeds it has been making a sucking/whistling sound. It almost sounds like a pot of tea boiling, if i had to describe it. It only makes this sound when I am driving down the highway at 70-75 and for maybe 3-5 seconds at a time when it does it

The other day i was running it pretty hard and noticed that the sound did not go away like it usually does and i also noticed that my temp was around 230-235 degrees. Normally it runs a tad over 200. When this noise started I noticed that it was running closer to 210-215. I know it shouldnt be running this hot but I also recently figured out that I filled it with the wrong coolant when I changed the water pump (about 30,000 miles ago). Either way it never ran hot or even warm before and has recently started to at highway speeds.

other than this sound the truck runs fine. I cannot for the life of me figure out what the sound is or why it is running warm. Though I have an idea that the thermostat may be going out and not opening fully or at the right temp.

Any help/advice/suggestions that anyone could offer on why it is running hot or on what the sound is would be greatly appreciated.

Thanks in advance. If you need more info please ask.

 

What coolant did you put in, and was it flushed, or is something else mixed with HOAT?

I wonder if the fan clutch could be making that kind of noise?

 

I did not put HOAT back in it because I couldnt get HOAT at the time. SO pretty much it is HOAT mixed with something else? Could this be the problem with the temp?

 

Yeah, HOAT can turn into a gell like mess after a bit when mixed with something else.

I think I'd do a thorough chemical flush first and see if that cures it.

 

Just a note but HOAT can be found at all Chrysler/Dodge and Ford dealers. Also NAPA carries the Zerex G-05 HOAT coolant.

MikeyB