I have only pulled real heavy a couple of times with this truck and both times my engine temperature gets pretty hot when pulling steep grades for a long period of time.  During these grades I try to keep my EGTs around 1100-1200* but my engine temp spikes--getting real close to the 240* mark on the guage.  As soon as I get over the hill and am able to maintain my EGTs at a much cooler temp the engine cools down as well.

 

I flushed my radiator aboout 7,000 miles ago and it runs around 190* normally, and no leaks.

 

Is this normal or should I be looking at blocked air flow through the radiator?

Most likely blocked air flow or poor fan clutch. Fan clutch should lock up tight by about 208-210*F. I pulled many grades with EGT's around 1,100-1,200*F but always max'ed out the coolant temp at about 206-210*F. The face of radiator could be plugged with mud, oily residue from the crankcase vent, etc.

I second what Mike said. You should try to remove the fan and fan shroud and blow compressed air through the radiator to blow out all of the crud that builds up in it or if you have the time and wear with all, remove the radiator and pressure wash the radiator but keep the pressure washer pressure at a reasonable pressure so as not to damage the radiator core.

While we are on this note, the radiator coolant if using the green stuff (ethylene glycol) should be replaced every 2 years in some fashion or other. I use a Mity Vac to suction out the radiator and replace about 4 gallons of coolant on the wife's truck (uses the green stuff) and about every 5 - 7 years on my truck. (it uses the Shell ELC coolant). If the coolant is not replaced periodically, it can cause corrosion. This could cause the early demise of your heater core not to mention the eventual rodding or replacement of your radiator.

When your fan kicks on you WILL hear it. If your water temp is getting that high and you have not heard it then you probably need to think about a new fan clutch.

If the coolant is not replaced periodically, it can cause corrosion. This could cause the early demise of your heater core not to mention the eventual rodding or replacement of your radiator.

 

Doesn't matter what coolant you use the pH level will start out near a 7 pH. Then with time the pH level will shift and change to corrosive nature either acidic lower in pH number 0-6.9 or basic when it rises from 7.1-14. Either way and no matter what brand of coolant it should be flushed out and changed at a proper interval. I see it all so common a shop test for boil/freeze point but never check the pH level of the coolant till the coolant has rotted the guts of the engine and turn the coolant rusty brown. Now its way too late...

Doesn't matter what coolant you use the pH level will start out near a 7 pH. Then with time the pH level will shift and change to corrosive nature either acidic lower in pH number 0-6.9 or basic when it rises from 7.1-14. Either way and no matter what brand of coolant it should be flushed out and changed at a proper interval. I see it all so common a shop test for boil/freeze point but never check the pH level of the coolant till the coolant has rotted the guts of the engine and turn the coolant rusty brown. Now its way too late...

 

The green stuff may be cheaper and easier to use in the long run.  Really can't be sure on that but the Shell ELC coolants are Cummins approved and have worked well for me thus far. (knock on wood) 

 

http://s07.static-shell.com/content/dam/shell-new/local/business/rotella/downloads/pdf/rotella-coolants-brochure.pdf

I use the 50/50 mix because my well water is all out of wack!

The Chrysler spec HOAT is backward compatible to all CTD cooling systems and is what I will be switching to this summer as I am due for another flush. It is a five year 150k mile coolant. I plan on doing annual pH tests or maybe more depending on results to verify. Even if I can go four years in between flushes it will be twice the interval I'm doing now, which will be a win win for the pocket book and the environment.

I pulled my radiator todnight and it looks similar to the picture under the Crank Case Vent Mod.  So needless to say I wil add that mod before putting this all back together.  My plan was to soak this radiator in a degreaser and then carefully pressuer wash it.  I am hoping to find a plastic kid pool to soak in.  Is there a better way to do this?  Do I need to take a lot of care to avoid getting the water and soap inside the radiator?

 

Thanks,

Josh

You can get it boiled or whatever it is they do at radiator shops.  

Check for plugged/dirty radiator with oil from the crank case vent. After 200,000 miles and the stock set up, mine was caked with oil and dirt. A little engine degreaser and garden hose will clean it, that also requires ripping apart half the front end.

If you do get some soap and water in the radiator, don't worry about it. Just rinse it out and it will be fine.

Even after doing the http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/26-engine-systems/42-crankcase-vent-mod I still have to pull my radiator every few year too flush the face of the radiator out of caked in dirt and mud. Mine is not a strict pavement queen it spends quite a bit of time offroad.

Pulling the radiator looks like quite a job.

I had my radiator removed and front gear case cover off in 2 hours. Actually more like an hour and a half because I didn't have a 36 mm wrench to remove the fan so I took a spare 1-1/4" wrench and carefully ground 4mm out of it. Just kept checking it with a set of calipers and took a hair over 2mm off per side of the open end. That took close to a half an hour.

I got a fancy made fan wrench for the Dodge Cummins from JL Welding. One to hold the pulley and the other to twist the fan nut.

Sometimes they can be a real bear to get off! I got really lucky and it only took a couple of good smacks on the end of the wrench with a hammer and she came right off. There have been other times where I have not been nearly so lucky though.

You got pictures of this holder Mike? I have a few ideas on making one but would like to see what you have.

Edited July 15, 201411 yr by diesel4life

Sometimes they can be a real bear to get off! I got really lucky and it only took a couple of good smacks on the end of the wrench with a hammer and she came right off. There have been other times where I have not been nearly so lucky though.

You got pictures of this holder Mike? I have a few ideas on making one but would like to see what you have.

 

Sure do...