Hitting 100k miles on 3.0

mark1968 · August 13

I currently have a 2020 GMC Sierra Denali with the 3.0 and im getting very close to 100k miles when my extended warranty will run out. We love the truck and the mileage we get but Im a tad bit worried about going over 100k miles and am thinking i should be looking at trading it in on a newer one with lower miles. Id love to hear folks input who have over 100k miles on their 3.0 diesels and if they’ve seen any problem areas pop up.. Thanks!

KARNUT · August 13

1 hour ago, mark1968 said:

I currently have a 2020 GMC Sierra Denali with the 3.0 and im getting very close to 100k miles when my extended warranty will run out. We love the truck and the mileage we get but Im a tad bit worried about going over 100k miles and am thinking i should be looking at trading it in on a newer one with lower miles. Id love to hear folks input who have over 100k miles on their 3.0 diesels and if they’ve seen any problem areas pop up.. Thanks!

Generally 100K miles is a milestone with any vehicle. Most vehicles will go 200K miles with minimal maintenance. The first order of business is if it’s been reliable and is it paid for. I had two vehicles hit the 100K mark recently that were paid for and very reliable. That time both require brakes and tires as well. I made the decision to use the dealer and OEM parts. Both vehicles I’m going for 200K miles. Both are closing on 150K miles. Both were around 4K in maintenance for the 100K milestone. I’m plus 20K or more not trading those in with the same service as if new.

Grumpy Bear · August 13

2 hours ago, mark1968 said:

I currently have a 2020 GMC Sierra Denali with the 3.0 and im getting very close to 100k miles when my extended warranty will run out. We love the truck and the mileage we get but Im a tad bit worried about going over 100k miles and am thinking i should be looking at trading it in on a newer one with lower miles. Id love to hear folks input who have over 100k miles on their 3.0 diesels and if they’ve seen any problem areas pop up.. Thanks!

If you would agree that in general a purpose-built diesel motor is more reliable than gas, then she's just getting started. Not likely OTR commercial grade reliable but...

If you would agree then the remainder of my comment is valid. My 2015 pickup is gas. 182,000 miles on her. I've spent under $20 in failed part type maintenance so far. Even wear and tear items have been very low. Damage repairs have been minimal. OEM brakes still in play. Two sets of tires. Three or four sets of wiper blades. Fluid changes. Uses next to nothing for oil. Has outlived the warrant and the legal definition of "vehicle lifetime" (150K miles) and a pure joy to drive. If a deer doesn't do her in (or ignorant texter) it may well go double the current mileage. Photo last fall. Most recent.

Wifes Terrain is at 257K miles, and I just put my first real serious money into it rebuilding the suspension for the first time about a month ago. Uses oil, quart in 2500 or so and has been a pain in my butt but it drives nice. Looks acceptable and I still trust it to go on 500-mile day trips. Routine maintenance. A few non-routine repairs. VVT solenoids, evap system and the like. Just starting to show some rust. I'll cry when it dies. Like losing one of my pets. It has sort of grown on me. This spring. Most recent photo.

The 3.0 may have some issues that are unique to it. Deep dive those. Does it have scheduled major parts, like perhaps cam chain that you may not wish to deal with? But given them due weight. A $2K repair is WAY cheaper than a new ANYTHING. Have you kept up on all scheduled items using the severe schedule? Used good products and OEM or better repair parts? How's the body? Interior? Guess I'm saying, if you gave it a good chance, trust it.

Edited August 13 by Grumpy Bear

PunchT37 · August 13

Not to say it will go out tomorrow morning but, that oil pump belt is a 100k item. At least on the early versions.

mark1968 · August 13

Thanks. I appreciate the responses.. Our 3.0 engine was part of a limited recall early on for burning oil but since that time, we’ve only had a windshield wiper motor and coolant line failure (this did leave us stranded tho). We love this truck and alternate it with our 2022 Silverado 6.2l to drive back/forth from our homes. My wife really wants something more lifted and beefier so we’ve been looking at ZR2’s with Bison package.. But I think you’re right- we dont owe anything on it and its been a great truck even with the issues.. Ill have my local dealer do the 100k maintenance and see how it goes.. If we get another “stranded” issue before the 150k oil pump belt change, then ill trade it in..

Grover67 · August 13

2 hours ago, PunchT37 said:

Not to say it will go out tomorrow morning but, that oil pump belt is a 100k item. At least on the early versions.

It wasn't 100k on the LM2's, the new ones with the same belt are 200k I wouldn't even be concerned at that point....

https://www.youtube.com/watch?v=Ea5r6XAK3bk

Edited August 13 by Grover67

David Krueger · August 19

Thanks for the link. I watched it all. Engine failure do to a lack of oil. Great vidio. I have a 2021 LM2 diesel. I am trying to learn as much as I can about it.

Thanks again.

redwngr · August 20

If we're gonna try and give advice, and throw around mileages for scheduled replacement items, maybe it would be a good idea to post the correct info??

2023 LZO

2021 LM2 -- 150,000 miles or every 15 years.

John Barta, GM engineer on the 3.0 project, in an interview posted on youtube, indicated his group was being conservative when setting the 150,000 mile recommendation and that further testing since that time was the reason for increasing the interval to 200,000 miles.

Others have compared the belt part numbers and indicated they are the same part number. (I haven't verified...)