3.0L Duramax - who owns or has driven one

AlexB · October 31, 2020

8 hours ago, BurnsMax said:

Gotcha. Yes they all do come with a 10 speed. I wasn't thinking about the hard to find 3.73 gears. Mine has the 3.23s, I think I have only seen one person with the 3.73s

I have the off-road package, 10spd and 3.73s. i ordered some Fuel wheels, 18x9 but will keep my Duratracs since they have alot of tread left.

redwngr · October 31, 2020

3.73 is also available on Custom Max Trailering' with the 5.3L.

As name suggests, only available on 'Silverado Custom trim'.

BD1 Custom Max Trailering Package, includes (DPO) trailering mirrors, (BVT) assist steps, (CGN) Chevytec spray-on bedliner, (GT4) 3.73 axle ratio, (R7O) Cloth Rear Seat with Storage Package, (RIA) All-weather floor liners, LPO, (SIE) Tiered storage, LPO, (S41) Wheelhouse liners, LPO, (VBR) Rubber bed mat, LPO, (VOZ) Tonneau cover, LPO and (5VI) Tie-down, LPO
1 - Requires CK10543 Crew Cab Short Bed 4WD model, (NHT) Max Trailering Package, (L82) 5.3L EcoTec3 V8 engine, (G80) locking differential and (JL1) trailer brake controller. Not available with (STH) Rally Edition, (SGM) 22" High Gloss Black wheels, (9B9), (9C2) or (9D7) governors, any other assist steps or any other tonneau covers.

redwngr · October 31, 2020

Sierra does not currently have any equivalent packages that include 3.73 with any engine.

The package (B4U - Diesel Off-Road Package) that gets 3.73 with the LM2 is only available in Silverado, and only on LT and RST.

(B4U - Diesel Off-Road Package)

kenny_r · October 31, 2020

This is where I get confused with where GM’s head is at. Your gonna offer those gears, but only in a Chevy? And at that, only in mid grade trim levels? Doesn’t make sense. I bet there would be a huge demand for an ltz and high country with that gear option, even an slt or Denali since you can basically get every damn option with those trucks anyways.

beowulf77 · November 10, 2020

I posted a thread on it but I just got mine a cpl weeks ago... AT4 3.0L Sierra. Hard roll up cover installed. I can't seem to get over 17.5 mpg city or highway driving. I dont hard accelerate or brake... and am not sure if something is wrong or if it was my gas. I got it from QT up in Round Rock... not sure if that's relevant but QT in general has a good rep I thought. Not even sure what to look for to see if there's an issue. 420 miles. Was really expecting mileage in the 20s at least.

AlexB · November 10, 2020

5 minutes ago, beowulf77 said:

I posted a thread on it but I just got mine a cpl weeks ago... AT4 3.0L Sierra. Hard roll up cover installed. I can't seem to get over 17.5 mpg city or highway driving. I dont hard accelerate or brake... and am not sure if something is wrong or if it was my gas. I got it from QT up in Round Rock... not sure if that's relevant but QT in general has a good rep I thought. Not even sure what to look for to see if there's an issue. 420 miles. Was really expecting mileage in the 20s at least.

I have 3.73 gears, 4x4 and at 75mph I get 24mpg. If I've been driving city more than highway the mpg is less than 24. The only time I get 17 is towing a boat. Not sure what an AT4 is supposed to get. I only have a z71 offroad & towing package.

jnissen · November 10, 2020

I posted a thread on it but I just got mine a cpl weeks ago... AT4 3.0L Sierra. Hard roll up cover installed. I can't seem to get over 17.5 mpg city or highway driving. I dont hard accelerate or brake... and am not sure if something is wrong or if it was my gas. I got it from QT up in Round Rock... not sure if that's relevant but QT in general has a good rep I thought. Not even sure what to look for to see if there's an issue. 420 miles. Was really expecting mileage in the 20s at least.

Yeah something isn’t tight if you have never seen above 20. If your a lead foot I can see that but even mild performance I get low 20s. Are you looking at the 25, 50 or what mileage average?

Crazypontiac03 · November 29, 2020

On 11/9/2020 at 10:34 PM, beowulf77 said:

I posted a thread on it but I just got mine a cpl weeks ago... AT4 3.0L Sierra. Hard roll up cover installed. I can't seem to get over 17.5 mpg city or highway driving. I dont hard accelerate or brake... and am not sure if something is wrong or if it was my gas. I got it from QT up in Round Rock... not sure if that's relevant but QT in general has a good rep I thought. Not even sure what to look for to see if there's an issue. 420 miles. Was really expecting mileage in the 20s at least.

You’ve got an issue, I’m currently avg. 25.6 with almost 2k. Mainly rural/City driving. Even when purchased the lowest I saw was 22.5 on the first tank.

beowulf77 · November 30, 2020

On 11/10/2020 at 3:55 PM, jnissen said:

Yeah something isn’t tight if you have never seen above 20. If your a lead foot I can see that but even mild performance I get low 20s. Are you looking at the 25, 50 or what mileage average?

I'll check the 25/50/etc setting.

I hand-calculated my last half tank at fillup and got 19.8. The trip computer calculation was 17.2. So that's odd. I'll keep watching it. Just 1k miles so I will go to 2k til I take it in just to give it some time to self-correct.

redwngr · December 1, 2020

@beowulf77 Perhaps there is a reason for the poor performance?

https://gm-techlink.com/?p=13785

Loose Turbocharger Actuator Bolts

October 13, 2020

Some 2020-2021 Silverado and Sierra models equipped with the 3.0L turbocharged Duramax diesel engine (RPO LM2) may exhibit a lack of performance along with DTCs P003A (Turbocharger Boost Control Position Exceeded Learning Limit), P0046 (Turbocharger Boost Control Position Performance), P0299 (Engine Underboost) and/or P0234 (Engine Overboost). If these conditions are found, check for loose bolts on the turbocharger actuator. (Fig. 18)

Fig. 18

If any of the three actuator bolts are not fully seated (Fig. 19), the threads may be damaged and the turbocharger should be replaced. The actuator is not available as a service part.

If all the bolts are fully seats, continued with the diagnostics outlined in the appropriate Service Information.

Fig. 19

Kchampagne · December 1, 2020

14 hours ago, beowulf77 said:

I'll check the 25/50/etc setting.

I hand-calculated my last half tank at fillup and got 19.8. The trip computer calculation was 17.2. So that's odd. I'll keep watching it. Just 1k miles so I will go to 2k til I take it in just to give it some time to self-correct.

I wouldn't wait too long. Something is not right. You should be getting mpg in the mid 20s around town. Plus, parts on these engines seem to be low in inventory. I've had two parts on backorder over the last month.

Jcollette33 · December 1, 2020

I agree something definitely isn’t right. Whether it’s your display or actually something wrong w your engine you should have it checked. What is the fuel range on your fill up? I have one in the RST trim and I travel roughly an hr or more to work depending on the jobs location. Normally I fill up Monday morning and am good all week. The job I’ve been on for a majority of this year is probably 75% hwy and 25% county rds. On the hwy I’m going close to 70mph and 55-35 on the county rds. My truck averages 26-28 mpg daily. My best ever is 39.1 on an extended drive on a hwy going 55mph. The worst average I’ve had was 22 w a lot of city and idling. Good luck and keep us updated.

Jcollette33 · December 1, 2020

Btw good luck if you need parts. Mine was in the shop for two months waiting on a couple parts and I don’t think that supply is getting any better w the China plague going on. Hopefully your luck is better.

Raylon · December 4, 2020

Alright guys, I have the chance to pick up a Diesel Off Road Package LT 2021 for about $42k this weekend. It's only $2600 more than the equivalent Gasser with the 8 speed. Any reason to not go with the diesel? Seems like a no brainer after doing a little research. I perused these 36 pages and didn't really find anything saying for sure don't get one.

Kchampagne · December 4, 2020

51 minutes ago, Raylon said:

Alright guys, I have the chance to pick up a Diesel Off Road Package LT 2021 for about $42k this weekend. It's only $2600 more than the equivalent Gasser with the 8 speed. Any reason to not go with the diesel? Seems like a no brainer after doing a little research. I perused these 36 pages and didn't really find anything saying for sure don't get one.

Wow, that seems like a killer deal. I'd say go for it. The 3.0 and 10 speed are a great combo. I've had some minor warranty work on my 3.0, but I love it.