Chevy Truck owners PSA!

[Tall Paul]

Hello,
I have been a Chevy guy for many years and I’m 99% sure I’ll never buy another one because of the last 12 months.

Main reason for this post is to let you all know if you have a Any Chevy, GMC, Cadillac... etc. truck with the DOD AFM (displacement on demand Active fuel management) Have it shut off NOW! If you don’t know what this is it is a feature on GM trucks that cuts the engine in half down to 4 cylinders under low load via the lifters on the valves.

You can go to any shop and have it tuned off. This will avoid the following.

First of all before I get to the DOD bullshit the new GM digital 6 speed transmissions suck. If you think you can go the recommended 75k between services your wrong. Go every 30k.

Last August at 115k on my 2015 Silverado the transmission exploded. I had done a full service at 70k. POS cost me $4800 for a new transmission.

Then in February at 140k my motor blew a DOD lifter and it smoked the cam shaft costing me $9000 for a new motor!

Now this August my wife’s 08 Tahoe at 147k blew a lifter and it smoked the camshaft as well. Seeing as we owned the truck I decided I was not paying anyone again to do this as I know I could. I pulled the motor and did a full DOD delete on her truck. Lots of work but at the end of the day it only cost me $1600 and a few late nights.

If you have one of these GM vehicles I highly recommend you Google DOD failures or DOD Delete and get ahead of this costly know issue with these LS motors.

 

[Tall Paul]

 

[Tall Paul]

 

[Tall Paul]

Her truck has never ran better!

I hope this post helps at least one of you.

Cheers!
Paul

 

[tone-ny]

Good to hear that you were able to do it yourself. We have a 2015 GMC Sierra that has around 70K and is our tow vehicle. Will look at this, thanks for the heads up. You know technology has made these vehicles suck for the most part!

 

[Scap]

Buddy of mine has a 17 and it's at the shop now for new injectors. Bad injectors is a known issue on the newer direct injected gas engines, and GM isn't recalling them.

That being said, all brands have their issues. I've never been a fan of extended warranty, but as these engines get more and more complicated/complex it makes you wonder if it might actually be worth it.

 

[jfields]

Former ASE Master Mechanic here (Until 2009)! With General Motors and Ford both I find it’s always cyclical. They have an issue that becomes pretty known in the field. Even though not recalled, everyone from salesmen, parts guys, and service managers knows there are common problems. Your motor reminds me of the GM 4.1 & 4.5L from the early 2000’s. The wide angle on the pushrods and lifters were prone to cause issues with the camshaft lobes and lifters wearing out.
Caused performance issues to be sure.

That’s why I and most auto techs I’ve known have always bought Toyota!

 

[Scap]

That’s why I and most auto techs I’ve known have always bought Toyota!

But my Tacoma had a belt driven interference engine...nothing like having a timing belt break and scramble an engine. (It never broke, but it was something I worried about until I replaced it.)
There's something to be said about the ruggedness of Toyotas. I flogged mine daily for 11 years, and it was still kicking when I traded it in.

 

[jfields]

But my Tacoma had a belt driven interference engine...nothing like having a timing belt break and scramble an engine. (It never broke, but it was something I worried about until I replaced it.)
There's something to be said about the ruggedness of Toyotas. I flogged mine daily for 11 years, and it was still kicking when I traded it in.

I still have my 04 Toyota Tundra. Youngest daughter grew up in it as the family car and is just about to get her license. She asked Her mom and I to keep it. Over 200k miles and Very mechanically sound. Paint and wheels look a little rough from never being garage kept and three years of West Virginia salt/chemical winter roads.
Same for my 09 Tundra. Almost 350k miles, a lot of it hard for business. That one cost me a little over $1k for rear axle bearings, but other than that, the normal brakes, and oil changes.
I traded it for a 2020 Tundra a few weeks ago. We will see If they keep winning with my fourth one.
I never understood why Europeans and Asians made those interference motors. So easy to recess the valves in the heads just a little with no compression basically lost to prevent them from ever smacking the heads.

 

[kann]

@PaulTra Wrenching porn!

That's awesome you were able to do the tear down and fix, yourself. I wish I had that sort of mechanical knowledge. I know that when Dodge/Chrysler introduced MDS in 2005 and 2006, there were some pretty big issues with it, especially in the trucks. For those that own affected GMs, is there any way to preventatively identify this issue before it becomes a problem without a full engine teardown?

I own a 2005 Dodge Ram 5.7, which is the last "basic" engine before MDS and even more electronic nannies. I've only got about 115K on it, but I cannot see myself ever getting rid of it for something ridiculously more complicated. I like some of the conveniences that my wife's 2019 Renegade has, but not enough to convince me I need a new vehicle. I haven't had a car payment since 2007 and, kind of like John and his daughter, I've had this truck longer than I've had my teenager! My older daughter learned to drive in it, and I'm hoping that in a few years, my youngest will have that opportunity, as well.

 

[jfields]

I’m sure with computers these days it’s different, but I remember in the late eighties or early 90’s GM came out with that system for their Caddies and a few other lines. What a disaster that MDS system was.

 

[Scap]

I’m sure with computers these days it’s different, but I remember in the late eighties or early 90’s GM came out with that system for their Caddies and a few other lines. What a disaster that MDS system was.

I swear Cadillac (and Lincoln) is a code name for "expensive experimental prototype testing"

Some of the craziest ideas have been put on those premium brands before the pleebs get it.

Maybe Microsoft got their idea for selling/testing beta software from these two...

 

[PaulTra]

I swear Cadillac (and Lincoln) is a code name for "expensive experimental prototype testing"

Some of the craziest ideas have been put on those premium brands before the pleebs get it.

Maybe Microsoft got their idea for selling/testing beta software from these two...

That's exactly what it is. All the newest tech gets put in Caddies and Lincolns and after the issues have been worked out and the tech becomes cheaper to produce it gets trickled down in the cheaper line ups and is usually more reliable at that point. Mercedes is famous for it too. Their S Class is a test bed for the C Class.

 

[kann]

I’m sure with computers these days it’s different, but I remember in the late eighties or early 90’s GM came out with that system for their Caddies and a few other lines. What a disaster that MDS system was.

The V8-6-4! That may have been even earlier than that... maybe late 70s or early 80s. I remember reading about that in a magazine when I was much younger.

 

[Tall Paul]

@PaulTra Wrenching porn!

That's awesome you were able to do the tear down and fix, yourself. I wish I had that sort of mechanical knowledge. I know that when Dodge/Chrysler introduced MDS in 2005 and 2006, there were some pretty big issues with it, especially in the trucks. For those that own affected GMs, is there any way to preventatively identify this issue before it becomes a problem without a full engine teardown?

I own a 2005 Dodge Ram 5.7, which is the last "basic" engine before MDS and even more electronic nannies. I've only got about 115K on it, but I cannot see myself ever getting rid of it for something ridiculously more complicated. I like some of the conveniences that my wife's 2019 Renegade has, but not enough to convince me I need a new vehicle. I haven't had a car payment since 2007 and, kind of like John and his daughter, I've had this truck longer than I've had my teenager! My older daughter learned to drive in it, and I'm hoping that in a few years, my youngest will have that opportunity, as well.

Yes you can have the system turned off on the computer so it doesn’t engage the DOD system to run 4 Cylinders. When Chevy put the new motor in my truck they shut the system off from day one so this will never happen to my truck. My life’s I replaced the entire system with a DOD Delete kit.

Paul

 

[PaulTra]

Yes you can have the system turned off on the computer so it doesn’t engage the DOD system to run 4 Cylinders. When Chevy put the new motor in my truck they shut the system off from day one so this will never happen to my truck. My life’s I replaced the entire system with a DOD Delete kit.

Paul

I did similar to my G8 GT. It hasn't been in V4 mode close to a decade now.

 

[DePasta]

Not just Chevy but Daimler Chrysler as well. Have a 2013 Jeep Grand Cherokee with the hemi, MDS killed the lifters, luckily I caught it early and just had to replace those, but still $2000...and it was only a few thousand out of warranty, no support from them.

 

[smellysell]

I still have my 04 Toyota Tundra. Youngest daughter grew up in it as the family car and is just about to get her license. She asked Her mom and I to keep it. Over 200k miles and Very mechanically sound. Paint and wheels look a little rough from never being garage kept and three years of West Virginia salt/chemical winter roads.
Same for my 09 Tundra. Almost 350k miles, a lot of it hard for business. That one cost me a little over $1k for rear axle bearings, but other than that, the normal brakes, and oil changes.
I traded it for a 2020 Tundra a few weeks ago. We will see If they keep winning with my fourth one.
I never understood why Europeans and Asians made those interference motors. So easy to recess the valves in the heads just a little with no compression basically lost to prevent them from ever smacking the heads.

Planning on getting a '05-'15 Tacoma to haul around Chemiste in as they have the slightly bigger body size. Might get an older Tundra instead depending on what I can find, but would prefer the mpg of the Tacoma.

 

[kann]

Planning on getting a '05-'15 Tacoma to haul around Chemiste in as they have the slightly bigger body size. Might get an older Tundra instead depending on what I can find, but would prefer the mpg of the Tacoma.

My first brand new vehicle was a 2002 Tacoma. Trading that in on a VW Jetta was the worst vehicular mistake I have ever made (though if I didn't get the Jetta I ended up hating so much, I would never have ended up with my Dodge Ram that I've loved for the past 15 years). I still miss it every time I see a photo of it. It was a manual trans, so I wouldn't be able to drive it anymore, but I kind of wish I still had it -- because I know it would still be running like a champ.

 

[jfields]

Planning on getting a '05-'15 Tacoma to haul around Chemiste in as they have the slightly bigger body size. Might get an older Tundra instead depending on what I can find, but would prefer the mpg of the Tacoma.

It’s pretty insignificant for what you get in the Tundra. The Tacoma literally only gets like two, maybe 3 mpg more. The reason I passed on them, along with my 6 foot 4 inch frame.