4th gen get cool down question

[shorthorn]

On my 05 cummins, I used to always allow the truck to idle until egts (per the pyro in the manifold) was below 350. Now my 2014 cummins I monitor EGT1 on my CTS Insight but the temp acts much different then the manifold mounted EGT pyro did.

Where is the sense for EGT1 located? What temps should I allow it to cool to before shutting it down?

 

[Mikepgsp]

I was told 400 degrees by Edge. Or five minutes when towing.

 

[sag2]

Don't be over thinking the cool down. I drive about a 1/4 mile into my subdivision from a 45 mph street. When I was driving a diesel I used to motor in at about 20 mph (keeps the neighbors happy too) and shut it off. I did pretty much the same routine anywhere I drove. The only time you really need to be concerned with cool down at all is if you are working the truck hard just before shut down. Otherwise don't give it a second thought.

 

[Stab]

Don't be over thinking the cool down. I drive about a 1/4 mile into my subdivision from a 45 mph street. When I was driving a diesel I used to motor in at about 20 mph (keeps the neighbors happy too) and shut it off. I did pretty much the same routine anywhere I drove. The only time you really need to be concerned with cool down at all is if you are working the truck hard just before shut down. Otherwise don't give it a second thought.

Ya but, it still brings concern every time I shut it down. Old habits!

 

[NIsaacs]

I can't say what is a good shut down temp on the new trucks, I think the turbo is water cooled??

However on my non stock older trucks, just accelerating from a stop light will get 6-700 degrees post turbo with a medium sized load. Then if you pull off for fuel, it is still hot and can take 2-3 minutes to cool down, even with the ac off. I shut down at 300* post. My pre turbo cools off quick but not my post turbo. I could not drive my trucks without a pyro

Nick

 

[Newsa]

I can't say what is a good shut down temp on the new trucks, I think the turbo is water cooled??

However on my non stock older trucks, just accelerating from a stop light will get 6-700 degrees post turbo with a medium sized load. Then if you pull off for fuel, it is still hot and can take 2-3 minutes to cool down, even with the ac off. I shut down at 300* post. My pre turbo cools off quick but not my post turbo. I could not drive my trucks without a pyro

Nick

Water cooled? I doubt it. Call me a monkey's uncle if i'm wrong. Oil lubed yes. And maybe a tiny bit of oil cooling. I never much worried about it when towing. It my turbo wasn't pulling much boost after leavimg the interstate and stopping at a red light, it already started cooling down.

 

[RVTRKN]

I was told 400 degrees by Edge. Or five minutes when towing.

I do 500*, I'll have to let it idle more than 5min to get to 350-400*, more like 10-15 minutes.

 

[Badunit]

Water cooled? I doubt it. Call me a monkey's uncle if i'm wrong.

No names. But it is water cooled.

 

[gsbrockman]

No names. But it is water cooled.

Correct...........these turbos have been water cooled in the RAM's since the first 6.7L in 2007.5

 

[AH64ID]

The turbo is water cooled, but very little of that cooling is for the bearing and most of it is for the electronics. It's better than a non water-cooled turbo but not the same as other water cooled turbo's like the Garretts.

That being said I was very surprised at how long it actually takes a turbo to cool down now that I watch pre and post EGT's. Pre can drop to 250-275° and be there for minutes before the post is below 400°, even after what seems like easy driving. 1/4-1/2 mile of subdivision driving really has minimal effect in my experience.

I shut down my fully water cooled turbo at 250° pre and 350° post.

 

[gsbrockman]

The turbo is water cooled, but very little of that cooling is for the bearing and most of it is for the electronics. It's better than a non water-cooled turbo but not the same as other water cooled turbo's like the Garretts.

That being said I was very surprised at how long it actually takes a turbo to cool down now that I watch pre and post EGT's. Pre can drop to 250-275° and be there for minutes before the post is below 400°, even after what seems like easy driving. 1/4-1/2 mile of subdivision driving really has minimal effect in my experience.

I shut down my fully water cooled turbo at 250° pre and 350° post.

At about what temperature would the oil start "coking" in a non-water cooled turbo vs. a water cooled turbo???

 

[RVTRKN]

No names. But it is water cooled.

View attachment 94785

There is still a cool down period of 1-5 minutes depending on use per , the manual.

 

[AH64ID]

At about what temperature would the oil start "coking" in a non-water cooled turbo vs. a water cooled turbo???

The oil will coke at the same temperature on both turbos. The advantage of the water cooled bearing is that even thou the water pump stops spinning the hot coolant still has a little flow due to thermal differences. This continues to pull heat out of the turbo after shutdown, unlike an oil cooled turbo. It is also a much larger amount of liquid to heat up after shutdown.

I believe that conventional oil can start to coke in the 225-250° range and good quality synthetics are good to 275-300°, but that is from memory.

There is still a cool down period of 1-5 minutes depending on use per , the manual.

IIRC the cool down period for the 6.7 is the same as the 5.9, meaning that Dodge/Ram doesn't think the water cooling does anything.

 

[Joseph Donnelly]

Probe location is in TDR 91, p. 95; it is just before the first trap. I wait for 350-370 deg on EGT1 to shut down.

 

[Newsa]

If you are driving relatively slow/doing some coasting (not pulling any boost) for 10 mins, is this the equivalent of idling for 5 mins?

I don't have an edge monitor and have no plans to buy one

 

[AH64ID]

If you are driving relatively slow/doing some coasting (not pulling any boost) for 10 mins, is this the equivalent of idling for 5 mins?


I don't have an edge monitor and have no plans to buy one

Not based on what I have seen with pre/post pyro's.





Good job owning your water cooled comment....

 

[RVTRKN]

I never pay attention to my 2014 W/O pyro, because I idle it a lot. But I was surprised to see my 07 C&C EGT at idle once I got my pyro when in regen it will climb to 800*. Now it's been doing it for a long time, and only the last couple of years was I aware of it. When my EB engages at idle I pay close attention to pyro.

 

[photowrite]

I was told 400 degrees by Edge. Or five minutes when towing.

Probe location is in TDR 91, p. 95; it is just before the first trap. I wait for 350-370 deg on EGT1 to shut down.

I've been using 400 degrees myself based on my experience and how much time it takes... Generally it takes longer, sometimes much, than the owner's manual suggestions that are based on loads, for it to reach 400 degrees.

Surely it can't hurt (other than a bit of fuel) to go as low as 350-370 as Joe suggests.

James

 

[sag2]

I agree that there is a cool down time listed, but using common sense and being that there are very few turbo failures on 5.9 or 6.7, I still stand by the fact that unless your running it hard there is no big concern with cool down.
Most 6.7 turbo failures were for sooting, not bearing failure.