Elevated exhaust temps

[ram17]

2017 6.7L Aisin CC short bed 4x4 13,500 miles loaded with a 3900 lb slide in camper. 2 days ago regen interrupted after 8 mins, 24 hrs later took the RAM on 15 min ride thru neighborhood streets to parkway where I drove it at 55 MPH for 45 mins with occasional momentary slow down to 5 MPH then right back up to speed.
I use a BAFX OBDII with Torque app to monitor EGTB1S1, S2, S3, S4, with S1 reaching 860 F at times while S2-S4 sensors stayed around 710 F. If I slowed down to 5 MPH S1 temp might drop tp 510 F then go right back up to around 790-830 F. EB and tow/Haul mode did not effect the temps. I don't recall S1 being this high nor being the higher than all the others. Is this normal if not what could account for this ​

 

[sag2]

It appears it was in regen. The temps can go as high as 1200 during a regen. Unless you have a CEL, quit looking at the temps. There isn't anything you can do to change them.

 

[Cummins12V98]

I don't know or care what my temps are because it's designed to not allow it to hurt it's self. 60k and I have no knowledge if or when it had done a re gen.

 

[ram17]

Thanks for the responses. Someone is always willing to help and share their knowledge, more so on this forum than many other forums. At first I was not too concerned when i saw what was happening and assumed it was continuation of an aborted regen. But what made me post was that this regen (if it was a regen) lasted well over 45 mins (mine go 20-30 mins at most) and usually S2 and S3 are much higher in temp than S1 and S4. Maybe wrongly but I associate S1 with temperature around the turbo, S2 and S3 temperature pre and post particulate filter, and S4 closer to temperature near exhaust termination. Bear with me on all this since I am a weekend mechanic who is only familiar with gas engines, diesel with it's EPA constraints is new to me. I wish I could be like you Cummmina12V98 but my nature is to be anal, maybe i'll eventually get there.

 

[kthaxton]

I wish I could be like you Cummmina12V98 but my nature is to be anal, maybe i'll eventually get there.

Oh, he's plenty anal too.

 

[Cummins12V98]

Oh, he's plenty anal too.

YUP, I have been accused of that MANY times! BUT there are a few things in life NOT worth worrying about!

 

[gsbrockman]

YUP, I have been accused of that MANY times! BUT there are a few things in life NOT worth worrying about!

Is PARTIAL transmission fluid changes one of them?

 

[Too Tall]

2017 6.7L Aisin CC short bed 4x4 13,500 miles loaded with a 3900 lb slide in camper. 2 days ago regen interrupted after 8 mins, 24 hrs later took the RAM on 15 min ride thru neighborhood streets to parkway where I drove it at 55 MPH for 45 mins with occasional momentary slow down to 5 MPH then right back up to speed.
I use a BAFX OBDII with Torque app to monitor EGTB1S1, S2, S3, S4, with S1 reaching 860 F at times while S2-S4 sensors stayed around 710 F. If I slowed down to 5 MPH S1 temp might drop tp 510 F then go right back up to around 790-830 F. EB and tow/Haul mode did not effect the temps. I don't recall S1 being this high nor being the higher than all the others. Is this normal if not what could account for this ​

My EGT1 behind the turbo run about 100 F above normal. I'm wondering if the torque app is not the problem. I have it but don't use it. Just ordered another ODBCII transmitter. Going to see if it's any better than a few years ago.

 

[Cummins12V98]

Is PARTIAL transmission fluid changes one of them?

Speaking of I am going to do my 60K change and I think i will post a new topic if anyone knows how to do a fluid exchange on an AISIN as I really don't want to do just the pan.

 

[David Hoffman]

Is there a document of sorts that will tell you which sensor is what for apps like Torque APP? For example is the EGTB1S1 the exhause and EGTB1S3 is the ???

 

[JR]

EGT1 DOC inlet
EGT2 DOC outlet
EGT3 DPF outlet
EGT4 SCR CAT midbed
EGT5 SCR CAT outlet

 

[CoastyAV8R]

What is the DOC? I know what the DPF and SCR are but the DOC is a new one for me.

 

[JR]

DOC = diesel oxidation catalyst. It is integrated into the down pipe on the ISB6.7. Converts CO and hydrocarbons into H20 and CO2.

 

[David Hoffman]

EGT1 DOC inlet
EGT2 DOC outlet
EGT3 DPF outlet
EGT4 SCR CAT midbed
EGT5 SCR CAT outlet

Thanks,.. and without giving away any super secrets.. How did you obtain this information?

Oh.. and I'm sure you guys may have seen Marion Blair, but he monitors one of or more of these for proper cool down of the turbo... which one of these is that? S1, 3, ???

 

[Newsa]

Thanks,.. and without giving away any super secrets.. How did you obtain this information?

Oh.. and I'm sure you guys may have seen Marion Blair, but he monitors one of or more of these for proper cool down of the turbo... which one of these is that? S1, 3, ???

EGT1 would be closest to the turbo exit and before or at the top.of the down pipe

 

[JR]

Thanks,.. and without giving away any super secrets.. How did you obtain this information?

Oh.. and I'm sure you guys may have seen Marion Blair, but he monitors one of or more of these for proper cool down of the turbo... which one of these is that? S1, 3, ???

I monitor with a Scangauge II, the above information among other places is directly off their Website.

Regarding the cool down, unless you are pulling really hard it's not generally necessary with these trucks. By the time you get off the freeway and find a fuel island to pull into your good. The only times I've let my gen 4 idle to cool down is after pulling loaded hay wagons or gravity wagons through the fields - this can work an engine depending on circumstances because of the soft ground, low speeds and high ambient temps. Even then it is as more about letting the engine cool as it is the turbo. Generally speaking, if the fan is engaged I'll let it idle until it disengages. But to answer your question, for that particular situation you would want to monitor EGT1. This sensor is located in the DOC (diesel oxidation catalyst), which is integrated into the down pipe.

Personally I'm more concerned with shutting down in the middle of a regen, high EGT's are sustained during this time.
Notice EGT3 at DPF outlet, its nearly twice the temp as EGT1 at the down pipe post turbo. If possible I will wait until regen is finished, a few minutes of idle time will cool everything down nicely before shutting the engine down.

 

[jhenderson]

The reason for cool down time is the turbo. Your info shows low temps post turbo. Higher temps at the def at shutdown won’t hurt anything.