Lz0 weird screeching noise.

[Gcmfishin]

Hey guys, I've been unable to find an answer to this question. Or have seen anyone else with this noise. Take a look at the video and let me know what you think.

New video by George Martinez

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[Duramaximus]

That's odd. Run it over to the dealership.

 

[downtheroadAR]

Almost sounds like coolant dripping onto something hot - any smell of coolant (or DEF) with steam ?

 

[Gcmfishin]

Thank you guys for your replies.

So yeah I might have to just run it over to the dealer which I honestly don't like anyone touching my things because you never know what they really do. I do know the first service is on them but I did my first oil change at 500 mi second oil change at 2000 mi. And I was thinking of just taking the dealer up on there first service and doing it at 5000 mi.

There is no smell of coolant or def fluid. The truck has 2500 miles now. I haven't refilled the deaf and I'm only down three bars. It seems like every region takes up a bar maybe? And all my fluid levels are in spec.

If anyone else wants to chime in, let me know what you think. I will update when it does go to the dealer and see what they say.

 

[Teegunn]

The DEF gauge on my 2020 AT4 3.0 diesel was very unreliable. No way I could get 2500 miles and still have 1 bar left. IDK if the DEF gauge is better in the newer 3.0 diesels, but it is something to think about. I'd fill up the DEF tank and see how much it actually needs.

 

[edeering03]

I have a new LZO - 1800 miles, same exact noise but more intermittent than yours. I was also waiting until first service to have dealer look at it. Let me know what you find. Its clearly something mechanical resonating at certain RPMs. I can hear it sometimes at idle, if I rev slowly it'll hit the different resonant points and I hear it. Can't be normal...sounds terrible

 

[Gcmfishin]

I will fill my deaf when I get home and see how many gallons it takes. Thanks for your heads up.

When I recorded the noise is because it was really wigging out pretty heavy. Normally it is more of a intermittent noise that comes and goes. I can hear it at idle on and off.

 

[Gcmfishin]

As for the def consumption. I got home and put 2.5 gallons. It took the whole jug. And now it's reading full.

 

[Dino76033]

I have the same noise. I work at an automotive repair shop and put the truck on a lift with a tech underneath it. He said its the little flapper valve inside the exhaust exactly where you recorded. He was able to pry on it with his knife and get it to stop momentarily.

 

[Teegunn]

As for the def consumption. I got home and put 2.5 gallons. It took the whole jug. And now it's reading full.

Wow, you got a lot of mileage out of 2.5 gallons of DEF!. Depending on ambient temps, how much I am pulling my job trailer, etc, I would get 1000 to 1500 on almost a full tank (5 gallons) of DEF. That was on my 2020 AT4 which I don't have any more. I mean DEF is relatively cheap, so not a big cost, but wonder why mine never got close to that kind of miles on a tank of DEF.

Glad to hear the poster above me figured out what the noise may be on yours. I don't ever remember a noise like that on mine, had the truck almost 3 years.

 

[jonlsu]

Wow, you got a lot of mileage out of 2.5 gallons of DEF!. Depending on ambient temps, how much I am pulling my job trailer, etc, I would get 1000 to 1500 on almost a full tank (5 gallons) of DEF. That was on my 2020 AT4 which I don't have any more. I mean DEF is relatively cheap, so not a big cost, but wonder why mine never got close to that kind of miles on a tank of DEF.

Glad to hear the poster above me figured out what the noise may be on yours. I don't ever remember a noise like that on mine, had the truck almost 3 years.

1000 miles on a tank of def?? Was that on a 2500? I don’t really tow anything, but on a full tank of def in the 1500, I’d say I get at least 8 to 10k miles.

 

[Teegunn]

1000 miles on a tank of def?? Was that on a 2500? I don’t really tow anything, but on a full tank of def in the 1500, I’d say I get at least 8 to 10k miles.

8 to 10K miles on a 5 gallon tank of DEF? Mine was always between 1000 and 2000 miles, depending on ambient temps, how much I was pulling my job trailer, etc.

My wife also has a 2020 AT4 3.0 diesel (I traded mine off). Hers probably gets 2000 miles per tank, she doesn't keep track though. I did keep track (wrote down the mileage after a fill up of DEF). But I am the one who fills up her DEF 95% of the time, so I know approximately how many miles per tank she is getting.

Not a 2500 BTW, just the 3.0 diesel AT4. I have no idea if where I live and the altitude (my house sits at 6100 ft I am in Montana) effect DEF usage. I do know when I am towing my 16' enclosed job trailer, that probably weight 6000 lbs normally loaded, I went through DEF faster. Also seemed air temps differences had some effect. But since I no longer have the truck, and don't plan on getting another diesel, or baby diesel AT4 since my diesel had so many problems at the end before I traded it, it's now moot for me. Except for my wifes AT4 - hope hers doesn't eventually have the same "service emissions system" error code that the dealership never could fix on mine after 4 weeks in the shop.

 

[pyoda]

I have '23 1500 AT4 and have the same exact noise coming from the same exact place since I took delivery in Dec '22, its intermittent. Can't say exactly how to reproduce it, I randomly hear it. Its going to the dealer tomorrow to have that sound looked at and CEL. Codes P20EE and P2C7A.

 

[doug13]

Based on my experience you are going to get a print out of a tech bulletin that says everything is a-okay

 

[zeeya]

I get the code P2C7A when I am on the lease roads for several days. (Very slow driving, speed limit is 20, but you can't that fast due to roads). It deals with the NOX sensors not reading correctly. When I hit the road coming home and drive it for a while it goes off. I have used the Banks I-dash to clear it as well. I imagine if you do a lot of in town driving, stuck in traffic for a long period of time it would do it as well. It has only done it after several days of working in that paticular area. 39 minutes to go 7.5 miles.
As far as DEF usage, I usually get an oil change out of the 4.5 gallon tank. If I am towing my bay boat it uses def faster. The gauge as mentioned above isn't that accurate. I put 2.5 gallons in when it gets one notch under a half of tank. The BANKS gauge shows it at 25% at that mark.