EcoDiesel Buzzing Sound from Engine After Shutoff

[Renegade]

If it’s like a lot of modern gas turbo engines, it has an electric coolant pump which continues after the engine shuts off to continue cooling the turbo.

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[lrtexasman]

Well, you've got EGR solenoids AND a butterfly valve operated by a solenoid which is located in the tail pipe (if it's the same as the Ram application which I'm assuming it is). The butterfly valve is there to create backpressure so that air will flow up the post-DPF EGR pipe. Both of these solenoids are audible and it is normal operation.

This is also why the engine response is so non-linear. As you'd imagine, purposefully controlling exhaust flow on the fly wreaks havoc with driveability. Thanks, EPA.

Thanks WXman. How's your Ram eco breaking in post oil leak/rusted injector repair?

 

[kcchiefs]

So, anybody else who has theirs hearing an irritating buzzing sound coming from the left side of the engine after turning it off? Not just something a car nut hears. My wife said: "What is that noise? Is it supposed to do that?" Fairly high pitched vibrating/buzzing sound. Does not sound like a pump unless it is a really small electric pump of some kind. I have not measured the timing on it, but it stays on a minute or so. Eventually goes off.

Turbo engines have a timer for cool down. This is normal.

 

[WXman]

Thanks WXman. How's your Ram eco breaking in post oil leak/rusted injector repair?

Lately it's drinking fuel and I don't know if it's because I'm not using additive right now, or if it's because winter fuel is being distributed again.

But, so far no more issues.

 

[lrtexasman]

Good. I’m sure you’re enjoying the extra cab room. Hopefully the glitches are gone.

 

[Saltymedic]

Mine does the same but not sure I'd agree with other options. It sounds electrically driven and intentional so I just figured it's just what it does. I know I'm not bringing much to the table since I haven't tried to bother popping the hood to figure it out.

 

[CaptNkllm]

1700 miles on mine and the buzzing sound is still their on shut down.. maybe they meant a couple 1000 miles? Not 500-1000 miles?

 

[Saltymedic]

Lately it's drinking fuel and I don't know if it's because I'm not using additive right now, or if it's because winter fuel is being distributed again.

But, so far no more issues.

I know this is off subject BUT. . This is my second ecodiesel and I can tell you for certain that it is sensitive to what fuel it gets. The problem being is you never know how good the diesel is that you're feeding until you run it. On two separate occasions my Ram ecodiesel awarded me with 30-32mpg when it usually ran around 26mpg (with good to average diesel). The fuel came from Shell and was a good distance from my home so I couldn't use it regularly. The worse mpg I ever saw was about 22mpg and it was after filling up at a Race Track. Long story short, after dancing around town experimenting with different stations I finally settled in to which stations had the better diesel and would only use those when I had to fuel up. I just wish I had that one Shell station closer to my house. BTW don't think assume all Shell fuel is as good, it's not. I have come to find that BP, Chevron and Shell were the most consistent but that was in Florida, I'm sure your area will vary. I would recommend starting off your search where the pumps are busy and grimey since the diesel doesn't have long to sit at those stations.

 

[Jeepasaurus_Rex]

I've got 6,000 on mine now and the buzzing is still there. I dont think its gonna go away

 

[Capricorn]

I have a 2021 3.0L Wrangler and the buzzing sound lasts exactly 3 minutes. Since it is so precise, it should be by design and not an abnormality. Every 2021 model I believe has that - some louder than others. When I test drove it, I did not notice it after shutdown as it was parked outdoors. But when I brought it home, it was very apparent in the closed garage.
It is definitely the coolant pump cooling the turbo, and that is a good thing. I brought it up with a service advisor at the dealer and he said the same thing.

 

[lrtexasman]

Yea someone posted where you are supposed to park and let it idle and cool down a couple minutes after driving. It’s in the manual. Gives different times for city driving, towing, and highway driving I believe.

 

[MrFlinestone]

Well, I heard from the dealer today on the buzzing sound after engine shutdown. I was told there was an internal FCA bulletin about this and it’s a normal ecodiesel turbo breakin noise regarding the spooling of the turbo. They told me it should go away sometime between 500-1000 miles. Not sure I buy that, but we will see.

As a side note, today I put over 400 miles of all types of driving on my new ecodiesel rubicon. Everything from mountain driving to interstate. Engine/trans have been perfect. The only issue I had is the ESC light flashed on and right back off 3 different times over about 300 miles of the trip from Alabama to North Carolina. First time, it shut off my adaptive cruise control. Hoping that’s not the beginning of an electrical issue or software bug, No service ESC warning or notification. Just flickered on and off. Anyone have any insight into this?

@JeepGuy82
Curious if that noise ever went away for you. Just picked up my gladiator and noticed the same sound.

 

[Capricorn]

It won't go off. It is by design. Two different service advisors gave me two different reasons.
One opinion is that it is the coolant pump. The other one said it is fuel circulating back.

But both said it is normal for all 3.0Ls.

 

[lrtexasman]

Checkout the JL forum regarding the same issue. You need to let the vehicle idle a certain amount of time after driving for the turbo to lubricate itself.

 

[Capricorn]

Checkout the JL forum regarding the same issue. You need to let the vehicle idle a certain amount of time after driving for the turbo to lubricate itself.

Yes.

From the manual:

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