Can I use my Cummins if I don't tow - My answer to a very frequent question

[Too Tall]

A video on using your truck for local running, What's that EGR doing to my engine. Results of my research.

https://youtu.be/dWscJr0VYQI

 

[Newsa]

Too tall, thanks for some excellent napping material. I see that you warmed up your monotone so that you would not be spewing any soot from your mouth. (Just kidding)

Glad to see you address several emissions concepts /issues (EGR, DPF, soot load on oil). Question #1...... Do people see a difference in soot load, and passive DPF regen in the winter? I am in Miami. I don't know if it's my morning driving style vs my afternoon driving style, but i see much lower EGT's when the temp is 60°F vs. 80°F. (On trips of 20-30 miles and watching EGT's). Addditionally, i am curious which EGT temp sensor best correlates to DPF temperature. My Temp Sensor #1 hardly ever gets over 700°F. Where EGT sensors #2 & #3 easily get over 1000°F. And one last question.....
At what EGT is it safe to shut down the truck (sensor#1) after towing hard? So as not to turn it off when the turbo has not adequately cooled?

Any comments welcome.

I don't put EGT sensor #4 on my screen, because i figure it's too far downstream to give me any relevant info. Am I correct with this????

 

[kthaxton]

Wait, at 0:45, did you say "Cummings"?

 

[Too Tall]

Wait, at 0:45, did you say "Cummings"?

That had to be a Freudian slip

 

[kthaxton]

Good thing there's no Cummins purists here. :-laf

 

[Too Tall]

Too tall, thanks for some excellent napping material. I see that you warmed up your monotone so that you would not be spewing any soot from your mouth. (Just kidding)

Glad to see you address several emissions concepts /issues (EGR, DPF, soot load on oil). Question #1...... Do people see a difference in soot load, and passive DPF regen in the winter? I am in Miami. I don't know if it's my morning driving style vs my afternoon driving style, but i see much lower EGT's when the temp is 60°F vs. 80°F. (On trips of 20-30 miles and watching EGT's). Addditionally, i am curious which EGT temp sensor best correlates to DPF temperature. My Temp Sensor #1 hardly ever gets over 700°F. Where EGT sensors #2 & #3 easily get over 1000°F. And one last question.....
At what EGT is it safe to shut down the truck (sensor#1) after towing hard? So as not to turn it off when the turbo has not adequately cooled?

Any comments welcome.

I don't put EGT sensor #4 on my screen, because i figure it's too far downstream to give me any relevant info. Am I correct with this????

I agree, DPF 4 is not relevant. I watch DPF pressure which will give you an idea of when you are getting closer to regen. EGT 1 is closest to the engine so it' a good one to watch for shutdown turbo cooling. I wait for 400 deg. or less before shutdown. I always heard 500 deg was safe but that' a little high for me, Anything less than 400 and you'll be sitting there a very long time, ha. When I'm towing and make a stop for fuel, I don't shut down. EGT 3 is the one I watch for DPF temp. It's the outlet of the DPF. EGT 2 will work also as that's where the Oxidation is taking place to heat the inlet of the DPF. IMO, there's a little advantage in the summer heat because the exhaust temps build up quicker since the engine is warming up quicker. Once warmed up, IMO, there's little difference. When I'm towing, EGT 1 and 3 will equalize in just a few minutes which is good for passive regen. Thanks you.

 

[LFrachtmonroe]

Can anyone tell me the relation between DPF pressure and EGT1? I watched the DPF pressure rise at low throttle (but at any speed) and then drop significantly letting off the throttle. I never saw it drop significantly at 75mph with the cruise on (no trailer or anything). Basically I'm trying to understand if there is a way to see that a regen is happening via Torque and my OBD2 scanner using the DPF pressure or EGT1 PIDs.

Thanks!

 

[Bob4x4]

Can anyone tell me the relation between DPF pressure and EGT1? I watched the DPF pressure rise at low throttle (but at any speed) and then drop significantly letting off the throttle. I never saw it drop significantly at 75mph with the cruise on (no trailer or anything). Basically I'm trying to understand if there is a way to see that a regen is happening via Torque and my OBD2 scanner using the DPF pressure or EGT1 PIDs.

Thanks!

The dpf pressure diferential will go up as flow goes up

 

[LFrachtmonroe]

The dpf pressure diferential will go up as flow goes up

So the torque PID "DPF Pressure" is actually the differential, and more=better? I was reading it all wrong, thinking that more pressure=more back pressure=more clogging=needs a regen.

 

[Bob4x4]

So the torque PID "DPF Pressure" is actually the differential, and more=better? I was reading it all wrong, thinking that more pressure=more back pressure=more clogging=needs a regen.

The pressure goes up is a natural thing that happens as flow goes up and restriction stays the same.More is not better but is used in the calculations to measure the increase in restriction.Higher pressure under similar loads will show How much restriction has increased.

 

[Bob4x4]

The op needs to research the different year 4th gens,they do not all operate the same/different sensors and strategies with different issues while being used as grocery getters.None of them LIKE it but some are more tolerent

 

[Minnow101]

Just because someone puts up some videos and advertises this on every Cummins related forum hoping for more clicks which equals more coin in his bank account certainly does not qualify this person as an expert. *Its just another guy with an opinion.*

 

[Newsa]

The op needs to research the different year 4th gens,they do not all operate the same/different sensors and strategies with different issues while being used as grocery getters.None of them LIKE it but some are more tolerent

I would like to see this.

I know TDR doesn't pit one year of ram against another year, or one trim ram against another trim, or one transmission against another....... (for fear of alienating some of its customers?) but it sounds like some research we might be interested in.

 

[sag2]

Can anyone tell me the relation between DPF pressure and EGT1? I watched the DPF pressure rise at low throttle (but at any speed) and then drop significantly letting off the throttle. I never saw it drop significantly at 75mph with the cruise on (no trailer or anything). Basically I'm trying to understand if there is a way to see that a regen is happening via Torque and my OBD2 scanner using the DPF pressure or EGT1 PIDs.

Thanks!

As Bob said flow goes up with engine speed. The reason for that is there is no throttle valve like on a gas engine so the flow of air through the engine is higher at higher rpm even when off the throttle which only cuts fuel, not air.

 

[Too Tall]

DPF pressure is reading the back pressure at the inlet. It goes up as exhaust pressure increases. At idle with no soot load, I see 0 psi. I usually know I'm getting close to a regen when I see .05 psi (at idle). I ignore it except when idling as that's is the one constant I can get a relevant reading to compare it to something.

 

[Newsa]

Can anyone tell me the relation between DPF pressure and EGT1? I watched the DPF pressure rise at low throttle (but at any speed) and then drop significantly letting off the throttle. I never saw it drop significantly at 75mph with the cruise on (no trailer or anything). Basically I'm trying to understand if there is a way to see that a regen is happening via Torque and my OBD2 scanner using the DPF pressure or EGT1 PIDs.

Thanks!

I don't think there is a relationship between EGT sensor 1 and DPF pressure. I agree with Too Tall that EGT1 is too far away from the DPF to tell if the DPF is hot enough to actively regen. Active regens happen above 600 °F and happen faster if it's above 1000°F. After driving for awhile with EGT2 & EGT3 above 1000°F, you might notice lower DPF pressures. At idle, I'm seeing 20-30 psi on the DPF pressure. But my sensor and programming is a bit different than the newer ones, i'd guess.