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Discussion Starter · #1 ·
Driving home last night, it was around 40 degrees. Cranked it up and let it run for a few minutes. I was heading home and when I came up to a stoplight, my truck engaged the jake brake without the switch being turned on or being in tow/haul mode. When it did this, the cab started smelling like diesel as I had the vent blowing. Then, it did again at the next light but it didn't do it again on the rest of the drive. Probably only went 7 miles in town. Thoughts? No codes showing.

Todd
 

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Driving home last night, it was around 40 degrees. Cranked it up and let it run for a few minutes. I was heading home and when I came up to a stoplight, my truck engaged the jake brake without the switch being turned on or being in tow/haul mode. When it did this, the cab started smelling like diesel as I had the vent blowing. Then, it did again at the next light but it didn't do it again on the rest of the drive. Probably only went 7 miles in town. Thoughts? No codes showing.

Todd
When it's cold out and the engine is cold the exhaust brake is engaged automatically to help accelerate the warm up of the engine. I don't know why you would have had the smell unless it was just coincidence from the general exhaust or something? BTW when the ECM engages the exhaust brake for warm up it doesn't activate the light on the button and the brake will only be active when you are stopped. In other words it won't engage during deceleration. It will do this until the engine warms up a little.
 

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I usually have the exhaust brake activated so I can't say mine has engaged with it deselected, but I have smelled strong diesel fumes in the cab on a couple of occasions. Thought it was another diesel vehicle up ahead of me until I smelled it recently and I was the only one on the road. It smells like a rich, unburned diesel smell, kind of like a Navistar/PowerStroke that has a bad injector. Not a cleanly burned diesel odor.

I'm wondering if during a passive regen the VNT activates to close off the turbo to build back pressure, and the gasses are vented overboard through the wastegate or some port? Maybe sending some fumes back out through the intake via the airbox?
 

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I usually have the exhaust brake activated so I can't say mine has engaged with it deselected, but I have smelled strong diesel fumes in the cab on a couple of occasions. Thought it was another diesel vehicle up ahead of me until I smelled it recently and I was the only one on the road. It smells like a rich, unburned diesel smell, kind of like a Navistar/PowerStroke that has a bad injector. Not a cleanly burned diesel odor.

I'm wondering if during a passive regen the VNT activates to close off the turbo to build back pressure, and the gasses are vented overboard through the wastegate or some port? Maybe sending some fumes back out through the intake via the airbox?
Passive regen occurs when the vehicle is creating hot enough exhaust gases to burn off the DPF without additional fuel input during the exhaust stroke... this won't occur under a stop condition....
 

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Truck was probably doing a REGEN. Exhaust brake automatically comes on(certain conditions must be met of course) when the truck is doing a REGEN . I would guess the smell is from the REGEN as well, sometimes I can get a hint of a little burned diesel smell when my 13' goes into REGEN.
 

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Your truck entered an active DPF regen. It automatically tightens up the VGT to hike up the exhaust pressure and the EGTs as part of the process. Smells can be noticed during regens (especially on new trucks with fewer miles on them!), but nothing to be worried about.

Long story short: completely normal!:thumbsup:

P.S. There isn't a wastegate on the 6.7L.
 

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Yep, mine does the same as well. Spoke with the service worker about it and they note that it's normal. When in normal cold operation, the exhaust brake is really on kicked on when you're at a stop, it doesn't perform its actual "Braking" function unless you either turned it on (full/smart) or if you've entered an active regeneration event. Sounds like the latter.
 

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Mine did this also but smelled like McDonalds with the biodiesel we have here LOL
 
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Truck was probably doing a REGEN. Exhaust brake automatically comes on(certain conditions must be met of course) when the truck is doing a REGEN . I would guess the smell is from the REGEN as well, sometimes I can get a hint of a little burned diesel smell when my 13' goes into REGEN.
this only occurs when the truck enters ACTIVE REGENERATION...
 

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Your truck entered an active DPF regen. It automatically tightens up the VGT to hike up the exhaust pressure and the EGTs as part of the process. Smells can be noticed during regens (especially on new trucks with fewer miles on them!), but nothing to be worried about.

Long story short: completely normal!:thumbsup:

P.S. There isn't a wastegate on the 6.7L.
Yes. :agree2:
 

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This is an important function. I can't figure out why RAM decided not to give us an indication that is happening, and what type of regen is occurring. I wonder why they chose to keep the owners so uninformed as to what the truck is going through? I have about 1200 miles on mine, and have nothing to indicate the truck has ever been through a regen yet. My driving is kind of erratic with hills & varying speed limits, so the instant MPG indicator is all over the map, no way to tell really, and I can't watch it all the time. I drive with Tow/Haul & exhaust brake on all the time, so maybe it hasn't happened yet. But I would like an indication.
 

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This is an important function. I can't figure out why RAM decided not to give us an indication that is happening, and what type of regen is occurring. I wonder why they chose to keep the owners so uninformed as to what the truck is going through? I have about 1200 miles on mine, and have nothing to indicate the truck has ever been through a regen yet. My driving is kind of erratic with hills & varying speed limits, so the instant MPG indicator is all over the map, no way to tell really, and I can't watch it all the time. I drive with Tow/Haul & exhaust brake on all the time, so maybe it hasn't happened yet. But I would like an indication.

They want it to be as seamless as possible, like you dont know its there.


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Discussion Starter · #14 ·
Thanks for the help. However, I would like to know why the cab filled up with unburnt diesel fumes?
 

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Fresh air intake pulling it in? Might be better to put it on recirculate if you can see it coming.

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Well technically regen is happening all the time when you drive the truck warmly...just passively
 

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NORMAL. My truck does this. Have you ever ran a big rig and flipped the EB on at idle? It smokes like crazy. same with these trucks, it adds more pollutants, and also higher exhaust temps for the DEF system. I have noticed mine come on also during a "regen" on a long idle.
It's just forcing diesel exhaust in places it is desined to do.
 

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I had my EB come on last week while in Phoenix, 70 degree temps and the engine warm. I had not activated the EB and noticed it when I decelerated. Did this 5/6 times until I used the button to turn it off. Then a short time later used the button to turn it back on and it seemed to work as it should. This is the only time this has occurred. I have 8,000 plus miles on the truck. Live in CO and bought the truck in Aug.
2013 68RFE 3500 LB SRW
 

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It has also happened to me when driving on the freeway 65 to 70 and get off and then coming to a stop, the fumes got so bad one time we had to let the windows down. This has happened about 3 times already. I do have less than 3000 miles on it.
 
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