You are most welcome my good friend!

 

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The testing I am referring to WAS on the early 5.9 Cummins 12 valve Sir! And as I told you in my post that testing was done in the Cummins Midrange Engine Plant located in Columbus, Indiana which is where I told you Mark Chapple worked Sir! If you still don't believe what I am saying I challenge you to call Mark Chapple and ask him yourself! Here is the number to his "TST Products" Company: (812) 342-6741. Tell him John Porterfield told you to call. Mark and Gina Chapple are friends of mine and he will know who I am.

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Respectfully,

John_P

 

What they are trying to say is that the 12v and CR (Common Rail 03-present) engines are not the same, they have different EGT tolerances.

Yes the 12V was tested at 1250 but the CR's are tested at a higher EGT (1500 i think it was).

 

Well, it appears the limit is 1250 if that's when the tuner defuels. Which Gen do you have?

Whatever the limit on each generation, the single probe gets an average temp from all six cylinders. If one or more cylinders is running hotter, for whatever reason, that cylinder could be over the limit while you are reading your redline limit on the gage. Based on my airplane EGT's with six-point EGT, each cylinder could be differing by 100-150F. I balanced the injectors, so now I see them all within 20-25F in cruise. This may or may not apply to a Cummins, but the injectors are at each cylinder in the head and the airflow is through a manifold with different length runners with different airflow volumes like the Cummins.

The newer rigs defuel, but how accurate is that feature? Personally, for a long pull with my 5er, I limit EGT (the right pedal) to no more than a continuous 1200F with a 1250F redline. Right or wrong, the motor has 331,000 miles and hasn't toasted itself, yet.

 

I'm not saying i don't believe what you're telling us, I'm saying that you're referring to a 12v and I'm talking about a CR. These engines are not going to have the same limitations.

 

I called Cummins on this. They forwarded me to Chrysler. Chrysler had no idea beyond what is in the owners manual. I asked if they could refer it to the engineering department. They needed owner information and I don't own a CR. Sudden disconnect. The guy didn't understand what I was talking about, because he wasn't trained to answer any questions that weren't included in the owners manual.

I call Cummins back and ask them, "What is the max EGT rating on a Cummins common rail engine like the ones installed in the Dodge Rams?" They needed the engine serial number.

I have exhausted my efforts to defeat the bureaucratic Catch 22 experience.

Someone with an engine serial number needs to get on www.cummins.com and ask this question. I just met Chapple once and don't feel right about bothering him on this. Perhaps someone who knows him could ask?

 

i have a third gen. 2005. Im asking for my personal comfort.. not because im trying to raise it. I do the same in just modulating my foot and gear im in when it defuels. if my 1250 mark is just the 'yellow' zone to the 1350 'redline'. ill gladly keep doing as ive been.. even considering your 100deg fluctuation between cylinders. i plan on keeping the truck forever.

 

Yep. I've bought my last truck. The emissions complication and enhanced computer control has dampened my enthusiasm. Rubbing a little repair/improvement money on the truck from time to time is a good trade off for me.

 

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The 5.9 Cummins CR Engines are not any "tougher" than the old 5.9 12 valve engines are. In fact, they have more cylinder head issues due to heat than the 12 valve cylinder heads do and you need to remember that they have four valves on each cylinder versus two on the 12 valves. So, you have more chances for valve issues, not less! Also, as I told you in one of my earlier posts the later 5.9 Cummins CR Engines as well as the 6.7 Cummins CR Engines run hotter coolant and oil temps than the 12 valves did and I saw that consistently on my later Dodge CTD CR Trucks!

You and the other members do what you want to with reference to the EGT's on these engines. DTR Member soulezoo also tried to explain to all of you about the damage from high EGT's on these engines so we have tried to help and caution you guys.

 

when i get time I'll check to see what Cummins tested these engines at. 1500* is what my research has told me, but I'll try to verify that.