Silverado 5.3 update 12/11

[403Olds]

I think my check engine light came on just under 20. Maybe it changed by year. How did you disable the DOD ? Ranger plug in ?

I was nervous about the lifters, so I did the Diablotune shortly after I bought it. Per the previous owner, mine had new lifters put in it at 132K, but I didn't want to take a chance, plus it bugged the OCD part of me, as I could feel it when it kicked in.

 

[Ernest]

At least this hasnt happened to you.

 

[Supercharged111]

At least this hasnt happened to you.

You guys are overthinking a non-mechanical AFM defeat, just unplug the MAP sensor on the brake booster. Keeps it in full freedom mode all the time and noticeably helped with oil consumption on our Envoy. Mileage seems the same.

 

[Built6spdMCSS]

I've turned a few off in the tune for people that swapped in the parts. Definitely would prefer to not own one.

 

[Supercharged111]

I've turned a few off in the tune for people that swapped in the parts. Definitely would prefer to not own one.

It's worth it to turn it off for someone who hasn't swapped in the parts too. Only thing I'm not sure of is if it's any less likely to fail once disabled but with OE guts still inside. They do give warning signs before shjttjng the bed tho, that's why I pulled the trigger on one with low miles and a silent valvetrain. I just hope it never comes to that.

 

[Built6spdMCSS]

Yea, I've done it for people who just wanted it off and they swapped in the parts later

 

[mikester]

The pressure relief in the oil pan is dumping the pressure to 40 psi. The stock pump for a DOD motor is 80 psi and the pressure relief knocks it down to 40 at the bearings and sensor. This is why they idle and drive at 40 psi give or take a little.

Mike - to delete the DOD and VVT takes a new timing cover, valley cover, Gen 3 oil pump, a 1/4” NPT pipe plug for the pressure relief in the pan and 8 lifters to replace the 8 DOD lifters. I recommend a Gen 3 cam at the same time to accept a Gen 3 cam gear. ***

Jake 81cutlass , if you have a DOD motor and it’s at 20 psi, then you have an issue.

Greg airboatgreg - the oil pump swap to fix this is crap. That’s the dealer and GM making an effort to get it out of warranty before it needs a cam, lifters and DOD actuators.

*** here’s the deal with DOD and VVT delete, it’s much more reliable, but the performance and fuel economy will suck *ss with a stock ECM and cam.


Personally, I’ve not seen a DOD motor make it 160k without the valley cover bolts being loose and taking out the cam, DOD lifters and 8 pushrods as well. I’m sure that there are many out there that have made it past this mileage, but most don’t. And FWIW, I have a ‘14 with 110k and I’m prepared to buy 8 DOD lifters, pushrods and oil pump the second I see the oil pressure drop to 30 psi.


Does everyone understand why loose valley cover bolts cause this catastrophe?

My 5.3 had loose valley cover bolts and was swapped at 160k due to the ‘motor is junk - low oil pressure and making noise’. I have a 4.8 with the same issue. Takes less than $800 of parts to delete DOD AND VVT. The issue is the cost of the labor. Point of reference, my 5.3 seen 30 psi of boost (900-1000hp) and I paid $250 for it as a core.

Anyone that has one of these motors that they want to sell for the core price - message me haha - I’m collecting them.

P.S. Texas Speed and Brian Tooley Racing sell the kits to delete and fix this issue.

My big question, why do the valley pan bolts loosen up ? No loctite before theyre put in ?

 

[Built6spdMCSS]

My big question, why do the valley pan bolts loosen up ? No loctite before theyre put in ?

Its the aluminum shrinking and expanding more than the steel bolt, it'll turn the bolt out over time.

 

[Rt Jam]

I have interest in this topic since I have the same 5.3L DOD in a car. It's a well maintained engine with 130,000kms.

On the highway I have seen 7L/100km with premium, 8L/100km with regular fuel. Also never had a car with such a wide range in mileage. When stuck in traffic, no DOD, or when there is a tank with alot of spirited driving, the mileage is terrible. This makes sense, a powerful car is going to use alot of fuel but in DOD mode on the highway. I do not want to give up this feature.

Has anyone tried just replacing the lifters, before they fail. I'd be happy to know a complete refresh would get me another 150,000km's.

 

[scoti]

Going to keep watching/learning from this one.

I picked-up an 07 Envoy Denali about a month ago from a wholesale deal. Everything seems to work fine now but I've never cared for the DOD/AFM set-ups. I figured for the investment, I get decent alum 5.3/4l60e cores & can drive it around as a back-up in the interim. The vehicle turned out nicer than expected & now someone wants to buy it as their (her) back-up. I was looking into whether disabling the system increased the chances of everything living longer.