Exhaust smell in cab

[tp0d]

I have experienced a pretty thick exhaust smell inside the cab in my '16 3500, typically at low speeds, and I swear its connected to a regen. Reason I say this, is the smell shows up infrequently with no other diesels in the area, and I have stopped the truck and felt the heat/smell from an active regen.. Cant smell anything under the hood during this time tho, but I smell it more when moving. Gets pretty noxious

Told dealer about it when I had the truck in shop 2wks ago, they said cant find a leak. I do however have some soot leakage from the EGR valve stem. Dealer poo-poo'd it, tech said "did you spray some kind of lube in there?" Seriously? I almost slapped him. Well, he cleaned the soot off the heat shield, and its back. Pic attached is of pre-dealer cleaning, (at 20kmiles). Have 24k now, its about half sooted up

any ideas?

tnx

-j

 

[jelag]

This is interesting.... I have the same smell on a 2013 3500.... I'll look for the soot tomorrow.... thanks for the insight

 

[sag2]

That is not the EGR valve in the photo, it is the EGR cooler bypass valve. There is a Star case specifically saying that soot around the shaft is normal and do not change it for soot around the shaft.

 

[PTsideshow]

Was going to ask the same question, 2016 2500 4x4 just over 4,000 miles and when the first regen started I too had a strong exhaust smell in cab. I was only going a short distance and the message changed to 80% filter filled when I stopped and it hasn't come back on to finish regen. I wasn't aware that you have to drive it for a while to complete it at one time. It hasn't come back that it has started again and neither has the smell.
Does it have to reach 100% again before it will restart the regen?

 

[Bob4x4]

No it does not.

 

[JohnWelch]

We have some 5500's at work with the newer urea systems and when they are in regen they have an ammonia smell, not a diesel smell, like my personal 2012 does when I come to a stop sometimes and it is in regen. Just a
thought, may be something else going on.

 

[jelag]

I think twin88cam might be on to something... the smell i get isn't really a diesel exhaust smell.... but its a chemical smell that I assume was exhaust.... with the cab as sealed as it is... I'm surprised you can get a smell like that in the cab.... unless its coming in through the fresh air inlet..

 

[Berrigan]

I think twin88cam might be on to something... the smell i get isn't really a diesel exhaust smell.... but its a chemical smell that I assume was exhaust.... with the cab as sealed as it is... I'm surprised you can get a smell like that in the cab.... unless its coming in through the fresh air inlet..

My observations, with 18k on my new truck I have observed regen about every 700 miles. It lowers instantaneous mpg about 8 to 10 mpg during regen. The regen takes about 20 to 25 minutes of driving to complete. The impact on fuel economy for that tank of fuel is negligible. Hitting more random red lights decreases fuel economy much more. During regen in the cooler months I can almost always smell the odor you describe when stopped at a red light. Once up to speed the odor is gone. It is my opinion that the fresh outside air being pulled in at a stop brings in the odor. When you get moving again the air velocity carries the odor underneath and behind the truck and you don't notice it. For that matter when I follow a 70s muscle car with a high lift and duration cam and a rich fuel ratio I definitely can smell that also. Now in the summer, and the HVAC on auto, the system does not pull in outside air (it will when the summer temps are mild and after driving a long time) and I never smelled the odor at all from May until October. Now I am back in the heat/fresh air mode I can smell it again about every 700 miles. Also note if you are moving down the freeway at high speeds on a trip your fresh air inlet or open window would never be able to let the odor enter the cab because of air velocity pushing it away from the inlets. Anyway that's my take on it and its no different than your buddy ripping one in the passenger seat. You smell it for a bit and then it goes away.

 

[odinjunior]

"Anyway that's my take on it and its no different than your buddy ripping one in the passenger seat. You smell it for a bit and then it goes away."

LOL thanks for that I needed a laugh this morning....

 

[Newsa]

That is not the EGR valve in the photo, it is the EGR cooler bypass valve. There is a Star case specifically saying that soot around the shaft is normal and do not change it for soot around the shaft.

Isn't the EGR valve on the other side?

 

[sag2]

Isn't the EGR valve on the other side?

Yes it is on the other side.