Jaketab

2020 Sierra 3.0 Duramax. I know for a fact that the DEF tank is at about 1/2 capacity. The DEF gauge has going from the correct reading to showing full - which is very inaccurate. Anyone have this problem? Hoping someone can shed light on this before I take it to the local GMC dealer and they give me the usual dumb look on their face. Thanks - J Tab

I reset the timer each time of regen. It varies from 11 to 13 hours. In the winter its more frequent due to warm up idling. Towing seems to cause more regen.

The tire pressure increase may be worth investigation. I have noticed that when tires are cold the vibration is less noticeable. Next time I find the time I will decrease the tire pressure after they heat up to see if that makes a difference. Typically on a hot day the pressure increases from 37 to 40 PSI. The factory tire on mine is the Bridgestone 275/50/R22.

Armydave - Sounds exactly the same complaint I have. Purchased the Denali last August 2020. Not a smooth ride at 75 mph. Had a road force balance 3 times. Dealer also put sensing instruments on on underframe. Dealer said all was normal. BS. Finally gave up. BTW - I have the 22 inch tires on mine. Somewhere in this forum I also started a thread on this topic.

CraneGuy - for the most part no. After several trips to service I just don't have the time to keep going back. The dealer continues to say everything is good. I hope someone else can prove this and suggest the remedy.

Thanks

The infotainment unit in my 2020 Sierra recently did an update. It required stopping the engine while the system updated. It took about 14 minutes. Does anyone know what was accomplished or installed in the update ? Thanks - J Tab

The minimum shipping charge to my address from the Dmax Store is $26.00 for the 7 quarts + filter. Not a good buy. Better off going to the dealer. Tough to find Wal Mart prices on this oil.

Sounds like the plan if shipping is reasonable. Comparing prices on Amazon and Ebay, that deal is hard to beat. Mobil 1 ESP will have to wait. The local Advance Auto has the gall to sell Mobil 1 ESP 0W-30 for $12.99 a quart. They can't even get the ESP (DexosD) 0W-20. Thanks - J Tab

Hello, Getting close to 2nd oil change on my 2020 Sierra 3.0L Duramax. To make certain I purchase the correct oil, I've included a link below. The best I can determine its the Mobil 1 ESP X2 0W-20 which has the DexosD rating. Other than the AC Delco DexosD, can others confirm that this is the correct oil for the 3.0 L Duramax? It appears at this point the local auto parts stores do not stock the Mobil 1 ESP OW-20 as of yet. The link below gives the product description. Thanks - J Tab www.mobil.com/en/lubricants/for-personal-vehicles/our-products/products/mobil-1-esp-x2-0w-20/

Yes, I used the funnel supplied with the vehicle. The spout extends into the filler about 4 inches. Possible it was not long enough or I did not have it inserted far enough to by-pass the flapper. Thanks - J Tab

Need advice. Went to add some anti gel to my 2020 3.0L Duramax today. Was going to give it a 10 oz shot of additive. (Power Services Diesel Full Additive with Cetane) Inserted the funnel about 4 inches. When I poured the additive in the fuel filler it would not take the additive, ran out, and made a mess. Question - is there something restricting just inside the filler ????? Possibly I need a longer funnel ???? Thanks - J Tab

Danny, Have you measured the width of your bed at both the front and rear ? If so, what are the measurements.? I just received the BAKFlip MX4. The hard aluminum panels measure 62". The width of my 2020 Sierra Denali varies from 63-5/8" in front to 62-1/8" at the tailgate. Regards - Jaketab

Just received my BAKFlip MX4 order below for a 2020 GMC Sierra Denali 1500 series – short bed. (With multi pro tailgate) Two concerns before I completely remove the parts from the box. The inside width measurements of the truck bed vary. The front width at the rear window measures 63-5/8”. The rear width at the tailgate measures 62-1/8”. The hard tri-fold panels measure 62”. Meaning front panel is 3/4’' will be too short on each side. This may be too much overlap to fit ??? I've already sent an email to REALTRUCK and will contact them by phone tomorrow. The second concern is the bed liner is the factory stock spray on liner. The front sealing bulkhead strip most likely not stay adhered to the textured finish.

Hello, On August 5, 2020 I purchased a 2020 GMC Sierra Denali 3.0 Duramax. The truck now has 2500 miles. Except for the wheel or drivetrain balance problem, I am very satisfied with the vehicle. The fuel economy is exceptional with great power. The Sierra has a vibration problem at highway speeds on the interstate highway. The problem is a continuing vibration at 60 – 75 mph. The vibration is felt mostly in the seats. The truck has the 22” Bridgestone Alenza Tires. (275/50/R22) The problem has not been remedied through four (4) trips to the dealer. The vehicle tires and wheels have been (Road Force) balanced 3 times. One tire has been replaced and the balance/vibration continues. I suspect part of the problem may be 6 ounces or more of weight on 2 of the tires. During the most recent service visit, the service tech preformed an EVA – Electronic Vibration Analysis and test drove the truck about 25 miles. Because the vibrations (graph analysis) were within GMC specs, no further warranty repairs can be made without the consent of the district service supervisor. I had the service manager ride with me and he agreed that there was indeed a vibration as I have claimed. In the order of good customer relationship, the service manager is currently seeking approval to have new tires installed on the vehicle. As of today I am waiting to hear back from the manager. Please chime in if you have experienced this. My question to other 2019 – 2020 GMC Sierra owners is this a similar ongoing problem and what may be the solution? Could the problem be related to the drivetrain/driveshaft??? Thanks and regards Jaketab