EGTs, Engine Temp, and Coking

[Georgia Cracker]

My pyro gets down to 300* quickly, even after extended high speed runs or 50 mile pulls. I have my PwrMaxCR set on 4/4 for general driving and 3/3 for towing. Stock exhaust.



I can usually get to 300* within 1 minute no matter how hot the day or long the trip. The Owner's Manual has a cool down schedule expressed in minutes.



What is the correlation between the two - engine temp and EGTs?

When the pyro reads 280* and the temp guage is slightly below center, it would seem logical to shut it off. If there is a hidden relationship between the two I would like to know.



The real question is, is it safe to shut down when the Pyro reads 300* irrespective of the amount of time it takes to get to that point. Are EGTs accurate for determining shut down time?



This question went unanswered on another board in a similar thread. The point was made during that thread that turbo bearing seldom "coke" regardless of the treatment, but thats another discussion.

 

[Loaded 45]

I run two pyros one pre turbo for the tst & one pyro post just in case. After a hard run the preturbo pyro will hit 300 deg on cooldown - the post turbo pyro takes up to an extra two minutes to hit 300 deg. I use the post for shutdown temps after a hard run. Normal driving I just shut the truck off, no cool down.



This is my 5 th cummins since 95 - no turbo problems yet -

having said that, probably blow my turbo tonight

 

[rbattelle]

It is a good rule to shut down below 300* post-turbo, regardless of engine coolant temp. Having said that, if I come to a stop after a long highway drive I always let it run for a little bit before shutdown even if the temp is already below 300. In fact, most of the time I wait until below 250, just to be sure. Plus, as JHardwick pointed out to me once, it's good to circulate some cool oil around the engine before shutdown.

 

[Gary - K7GLD]

At first, with my original '91 truck, I too was concerned about turbo cool-down - but as I got settled in to the truck, I eventually took a couple of minutes for cool down after a hard pull with our RV to shut down, but other than that, just maybe 30 seconds or so, and shut her off... Truck had nearly 120,000 miles when I got the '02 - never the slightest problem with the turbo - or anything else for that matter - musta been the STP and my Frantz bypass filter... (inside joke... )