So my top radiator hose blew today replaced it and threw in coolant i could afford but i can tell its not keeping it as cool as it should be. So i am going to be doing a flush soon, so i ask what fluid does everyone recommend that is heavy enough for these hot engines?

 

First, as far as cooling goes, all the coolants will be the same.
Water is the best for heat transfer, but unfortunately it tends to freeze, boil and corrode metal parts.
So we mix water with ethylene glycol, which lowers the freeze point, and increases the boiling point of the mixture.

Corrosion, however, is another story. For that, coolant makers add various packs of chemicals to handle corrosion to various metals. This is why running straight water in a modern engine is a problem - not because of lack of cooling, but because of corrosion eating through fragile metal parts.

In addition, lots of diesels(like ours) require special additives for protection against cavitation.
Cavitation is what happens when the high cylinder pressures of a diesel actually flex the cylinder wall and cause micro bubbles in the coolant, which slowly strip metal off the walls until you end up with a pinhole leaking water into the cylinder. Not good.

As far as what coolant you should use:
I recommend Zerex HD ELC - Valvoline? ZEREX? Extended Life Antifreeze / Coolant : Product Catalog - Valvoline®

You can also use a standard green silicate-free coolant, provided you use a SCA(Supplemental Coolant Additive) like NapaKool. You will also have to check the levels of this SCA every 6 months or so with a test-strip, and add more as needed.

ELC coolants don't require this sort of checking, so in my mind they are 'better'.

 

Ok so would replacing the thermostat help too? I've been he long garrett with this truck since he's bought it, at first the truck handled highway speeds fine (70-80) one day she got pretty hot and we were able to determine that keeping her at 65 on the highway did the trick and kept her cool (a/c on too) with what happened today I'm thinking not only does he need a coolant flush but perhaps a new thermostat as well?

 

I'd definitely replace it.
Also, while in there, you'll find a little metal check ball inside the upper radiator hose housing piece - remove it, and you'll find that you can bleed the system of air /much/ better... and it doesn't seem to negatively affect warming up.

 

Awesome, thx for the tip macrobb!

 

So i replaced the t-stat and took out the little ball but when i get up to highway speed it still gets super hot and sits between the A and the L. So im guessing that a full flush will fix it but ive already basically flushed it with how much ive been trying to mess with it and fix it so im at a loss and csnt figure out what in the world is causing it to get so hot and only on the highway because driving at 50 and under it stays nice and cool.

 

Do you have an actual temperature or just going off the dash gauge? They aren't terribly reliable.

 

No i use the one on the dash, do you recommend any aftermarket temp gauges?

 

The dash one could technically be calibrated but is currently little more than a dummy.

I temporarily run a cheap little 3 gauge setup from O'Reilly which I wouldn't recommend...but it works fine and was cheap. Coolant and oil pressure, and ammeter for a different project.
My pillar EGT and PSI gauges are Autometer Phantoms which is a great gauge for the price if you're looking. I still have to get either oil or water temperature for my last socket in the pillar.

My point is this: your temps could be perfectly fine and you wouldn't even know it, since the stock gauges don't tell you numbers.
Does your fan roar to life when you're pulling a hill or otherwise working the engine?

 

I dont think it does i normally am playing music and a/c but from whatbi can think no it dosent roar.

 

If the fan isn't roaring when pushing the engine hard then you've got a few possible issues, assuming you have an otherwise healthy cooling system:
Radiator clogged, or fan clutch not working right. Both are fairly common.
Easy diagnosis on the radiator would be to get/borrow an infrared temp gun, and measure both hoses once the engine is warm. There should be about 15* difference between the two. If much higher than that, then the radiator is clogged. Believe it or not this will keep the fan from engaging as well.
Assuming that's good the fan clutch test is to block off the radiator with cardboard, cutting a hold in the cardboard the size of the fan clutch. This lets only hot air to the clutch and after idling the engine at operating temperature will trigger the fan to lock up and do it's thing.

 

I will do both those test as soon as i can and ill get back to the forum and say what it is. Also do you know of any videos or pictures of someone doing the fan test with the cardboard because i think i understand what your saying to do but i wanna be sure i do it right

 

@garrett I'd like to say your fan clutch is working right, cause yesterday when I was moving the throttle I felt the air being blown towards me, how ever it wouldnt be a bad idea to try josh's idea, also @josh I'm assuming the cardboard would go in front of the radiator??

 

Sorry I don't have any links, but I'm sure there's videos about how to do it.

Cardboard goes in front of the radiator, the hole lines up roughly with the fan clutch.

 

Ok yes i know, another starter thread, yes i read the sticky, how ever when i bought this truck, i replaced both batteries and theyre only 2 months old, alternator looks fairly new, havent had problems with the batteries keeping charged, the truck always turns over within a second literally, at about 6pm i went to start the truck and got a click, i checked terminals theyre all tight, went ahead and plugged in the battery maintainer just incase it was the batteries, i got 85F350IDI to come over and give me.his opinion he thinks its the starter. Any suggestions? Also 85F350IDI said that the cummins starters are interchangeable any word on that?