What do the Exhaust valves do and why do they keep running after the truck is off?

[CJ99X]

Ever since my truck was new, I would notice a high-pitched sound and clicking happening around the rear axle. I figured it had something to do with emissions equipment.

It doesn't really bother me, but after I turn off the truck and lock the doors, I noticed that sh*t is happening down there for a good 3-5 minutes.
Even if I hop in my truck to get something turn it on (without engine start), and then I hop back out, the process starts over again.

Today, I decided to crawl under and see what's making the noise and I found these, on on each side just clicking, whining, clicking, whining:

Some internet searching and I confirmed they are what they look like, butterfly valve actuators, or more specifically Exhaust Valve Actuators.
I assume they have something to do with the EGR system.

I'm just really curious why they're so busy when the truck is completely off and locked.
I don't know if they're opening/closing continuously or if they're just constantly re-checking their position, but it seems that if they're working so much, they're bound to eventually wear out and fail.

It is controlling the rate in which the SCR system injector and DPF cool to keep them from "mudding" up. I noticed this on my 3500 and that was the explanation given by a mechanic at the local diesel shop. Seems it is keeping heat then allowing a cool burst of air to create a syphoning drying effect across the units to evaporate any moisture it senses in the system. Is he full of it I don't know but it has been the best explanation I heard.

 

[66Fuelie]

I did look in the service manual and it really didn't give an explanations except that it is part of the emissions system. It pretty much gives a description of everything else but not that valve.
Tom

 

[Chris3058]

What do you need? Mine covers all the engines for 2020
Tom

Looking for the 3.0 ED….

 

[66Fuelie]

Looking for the 3.0 ED….

Mine covers the ED engine....

 

[DieselFuelOnly]

I did look in the service manual and it really didn't give an explanations except that it is part of the emissions system. It pretty much gives a description of everything else but not that valve.
Tom

Any chance you could send a copy of this explanation in the service manual?
I‘m going to take my rig to the dealer and I’m fully expecting them to try and say it’s not part of the emission system in attempt to not cover it!

 

[DieselFuelOnly]

Anyone home?

 

[Rebel_driver]

Gold plan should cover it?? But open the actuator cover and spray some lithium grease in. I had a squeak at shutdown and followed seadog’s recommendation in the link to the other forum.

How do you open the actuator cover? And can you repost the link? I am having this issue too I believe.

 

[Rebel_driver]

My actuator is now squeaking everytime I go from idle to throttle, when i shut off the engine, and even when i open my door after the engine is already off. Truck is 2020 with barely over 50k km. Dealer gold tier warranty won't cover it.

Is there an easy way to delete this part only? Will the truck freak out if i cut it out and straight pipe the section?

I am having the exact same symptoms. Did you end up figuring it out?