100K Mile Service Suggestions

Minnvmax · July 28, 2023

Coming up on 100K and I want to make everything right. Wondering what is suggested. I already purchased plugs so that for sure. Thinking belt and coolant flush. All other fluids have been maintained. Maybe even tensioner pulley while its apart? Should I worry about coils, water pump, etc? I don't want to fix things that aren't broken but a buddy with Dodge did the coils and pump as preventative maint. I had never heard of that before. Thanks.

diyer2 · July 28, 2023

I would do the water pump, with a 100k its time is limited I think. I replace wear parts to prevent being stranded and having it towed.

chem_man · July 29, 2023

I would suggest dropping the transmission pan and doing a filter and fluid change (provided it is an automatic), flush the brake hydraulic system, check the brake pads for adequate friction material, change the differential fluid (front and rear if 4WD), change the transfer case fluid if 4WD, new serpentine belt(s), new cooling system hoses, add a bottle of Techron Complete to your next 3 fuel fill-ups to keep the tips of the fuel injectors clean, get a CRC GDI kit (https://www.crcindustries.com/gdi-service-pack-1-kit/), new air filter, have the alternator's output checked to make sure it's not putting out too much AC ripple voltage, and grease anything with a zerk fitting.

Good Luck!

Jus Cruisin · July 29, 2023

Just replace everything. ;).....buy a new one.

Enough · July 29, 2023

You must be on the wrong forum.... everybody on this forum has had 157 lifters and pushrods replaced, is on their second engine and transmission replacement, third blown A/C compressor, second oil cooler line, third rear glass replacement, etc. , etc. in the first 40,000 miles !

Thanks for coming on and posting positive news !!! Congrats on the 100K !

I'm at 52K. Idler pulley and belt replaced and rear window leak fixed. 5.3 with 22.3 MPG average to this point.

Reading most of this forum I expected mine to blow up out from underneath me like a cheap Chinese firework !

Fluid changes, belts and hoses, plugs, water pump, and the other things mentioned in other post should be the ticket.

Most important do what you have been doing for the past 100K. Your truck likes it !!

Grumpy Bear · July 30, 2023

On 7/28/2023 at 10:16 AM, Minnvmax said:

I don't want to fix things that aren't broken

Get out that service manual and find the "Severe Service Schedule". The list in a Haynes Manual is a bit more exhaustive.

The key to your wish quoted is inspection and testing. The list help you capture everything your memory will forget.

redwngr · July 30, 2023

If you lost or didn't get the manual, a free pdf can be downloaded from GMC or Chevy sites.

This is from 2018 manual, but 2019 will be similar/same.

BIGDOGx · August 2, 2023

On 7/29/2023 at 4:19 PM, Enough said:

You must be on the wrong forum.... everybody on this forum has had 157 lifters and pushrods replaced, is on their second engine and transmission replacement, third blown A/C compressor, second oil cooler line, third rear glass replacement, etc. , etc. in the first 40,000 miles !

Thanks for coming on and posting positive news !!! Congrats on the 100K !

I'm at 52K. Idler pulley and belt replaced and rear window leak fixed. 5.3 with 22.3 MPG average to this point.

Reading most of this forum I expected mine to blow up out from underneath me like a cheap Chinese firework !

Fluid changes, belts and hoses, plugs, water pump, and the other things mentioned in other post should be the ticket.

Most important do what you have been doing for the past 100K. Your truck likes it !!

Don't jinx yourself, the lifter issues is real and has happened to tens of thousands of people who own these trucks. Gm has let the issue continue through 9 model years now starting in 2014. Yes i understand gm has made over a million of them but hey drop a lifter and get a 6+k engine repair bill and you soon wont give a flip about the million trucks that didn't have the issue!

With these engines I worry about caking issues more then anything, high mileage and that issue is not a good mix and i have seen a person on here like 5 years ago now at only 40,000 miles and 2 years of driving crack his head off and look at the backside of the valves and yikes is all i can say.

KARNUT · August 2, 2023

52 minutes ago, BIGDOGx said:

Don't jinx yourself, the lifter issues is real and has happened to tens of thousands of people who own these trucks. Gm has let the issue continue through 9 model years now starting in 2014. Yes i understand gm has made over a million of them but hey drop a lifter and get a 6+k engine repair bill and you soon wont give a flip about the million trucks that didn't have the issue!

With these engines I worry about caking issues more then anything, high mileage and that issue is not a good mix and i have seen a person on here like 5 years ago now at only 40,000 miles and 2 years of driving crack his head off and look at the backside of the valves and yikes is all i can say.

The whole idea for cylinder deactivation was for GMs numbers not the buyers. Right on the window sticker it claims 1-2 miles a gallon. This was on the trucks that didn’t have the chip to make it work. And here’s a 50$ rebate.

Grumpy Bear · August 2, 2023

2022 EPA numbers for the 5.3 with six speed is 19 highway, 15 city. With the 8 speed 21 and 16. If it says on the sticker that DFM/AFM is good for 1 to 2 mpg that is 5 to 10% splitting the difference. I'll take that all day.

Two possible issues can cause failure, non-lubrication failures or lubrication. If were simply a design flaw, then the number of failures would be near 100%. They are not. Even if tens of thousands fail, millions don't. GM Chevy/GMC produced about 2 million units a year since 2014 with over half those being trucks/truck-based SUV. Millions of these do well. K2 and T1.

This has been tagged may times. Melling, the main supplier has noted repeatedly that these failures are rarely mechanical and when they are, heat treat related; and almost always lubrication related when parts are examined upon return. I've wore that link out.

I've beat that lubrication horse senseless. He's as dead as the motors of those fail to recognize simple truths. The oil must keep the motor free of varnish and foam.

Not this:

This!

(Photos from Biosynthetic Technologies)

How many times have you heard, "I lost a lifter right after I passed this guy"? Foam.

I'd bet the overwhelming majority of failures are not dumb design but dumb/cheap/uninformed/headstrong owner.

The rest? As diyer2 says. "Luck of the draw"

Edited August 2, 2023 by Grumpy Bear

KARNUT · August 2, 2023

2 hours ago, Grumpy Bear said:

2022 EPA numbers for the 5.3 with six speed is 19 highway, 15 city. With the 8 speed 21 and 16. If it says on the sticker that DFM/AFM is good for 1 to 2 mpg that is 5 to 10% splitting the difference. I'll take that all day.

Two possible issues can cause failure, non-lubrication failures or lubrication. If were simply a design flaw, then the number of failures would be near 100%. They are not. Even if tens of thousands fail, millions don't. GM Chevy/GMC produced about 2 million units a year since 2014 with over half those being trucks/truck-based SUV. Millions of these do well. K2 and T1.

This has been tagged may times. Melling, the main supplier has noted repeatedly that these failures are rarely mechanical and when they are, heat treat related; and almost always lubrication related when parts are examined upon return. I've wore that link out.

I've beat that lubrication horse senseless. He's as dead as the motors of those fail to recognize simple truths. The oil must keep the motor free of varnish and foam.

Not this:

This!

(Photos from Biosynthetic Technologies)

How many times have you heard, "I lost a lifter right after I passed this guy"? Foam.

I'd bet the overwhelming majority of failures are not dumb design but dumb/cheap/uninformed/headstrong owner.

The rest? As diyer2 says. "Luck of the draw"

I realize some people like cylinder deactivation. Of course some people don’t really care until they have to replace those components. What peaked my interest is the fuel mileage you stated. My 14 GMC 5.3 with the 342 gear and 6 speed got 22 mpg at 72 mpg all day long with cylinder deactivation off. Much better on secondary roads. I have a picture somewhere on here on an old gas mileage thread showing that. I’m too lazy to dig for it. So now you need cylinder deactivation to reach the mpgs, that’s interesting.

Edited August 2, 2023 by KARNUT

Grumpy Bear · August 2, 2023

37 minutes ago, KARNUT said:

I realize some people like cylinder deactivation. Of course some people don’t really care until they have to replace those components. What peaked my interest is the fuel mileage you stated. My 14 GMC 5.3 with the 342 gear and 6 speed got 22 mpg at 72 mpg all day long with cylinder deactivation off. Much better on secondary roads. I have a picture somewhere on here on an old gas mileage thread showing that. I’m too lazy to dig for it. So now you need cylinder deactivation to reach the mpgs, that’s interesting.

Gave the EPA rating. You get better mileage? Great! Me too. Fact is, I get as better mileage on E-85 than most folks do on gasoline. :crackup:

Mileage wasn't the point I was making.

Edited August 2, 2023 by Grumpy Bear

diyer2 · August 3, 2023

More frequent OCI's, cheap compared to repairing a motor.

Minnvmax · August 3, 2023

Thanks for all the replys! Good conversation. I do take care of my truck so reaching this mileage is a reward, I guess..

Ill get to most of those items prior to winter although Im still on the fence for a few. The "old" 6.2 is still fun to drive and doesnt seem like its changed at all from brand new. ALTHOUGH my magical 10-speed transmission is NOT as smooth as it once was and worrys me a little once in a while.

KARNUT · August 3, 2023

1 hour ago, diyer2 said:

More frequent OCI's, cheap compared to repairing a motor.

I used to be extended when driving 50k plus miles a year before direct injection and cylinder deactivation. Using Amsoil and testing in the beginning. Never a problem. Fast forward in the direct injection cylinder deactivation world of today I’m running the severe duty maintenance. My wife’s Genesis was on that schedule they recommended and with 10-100k warranty I didn’t want to chance it. Later buying my avalanche with complete maintenance records and 3K oil changes. I could compare visually with my odyssey that had about 8-10k oil change. The Genesis and Avalanche oils no matter the mileage up to the next oil change are transparent. Very clean looking. The odyssey is dirty looking to the point of being alarming. Almost at fire up after an oil change. When I got it from my daughter it was at 50 percent. It got changed. One trip later changed again. It’s looking better. My only cylinder deactivation engine so for awhile it’s getting 3K oil changes probably from now on.