Tahoe/Silverado Problem #2

[Mark L.]

This is a PSA as many of you likely have a newer Tahoe or Silverado. My last post on these vehicles had to do with the cylinder deactivation problem with my 2021 which resulted in a total top end tear down at 4500 miles. This time it is what is called "cranks but doesn't start" with 20000 miles. At least I was stranded in a parking lot at a local restaurant. Now the fun part...can't get the vehicle in neutral because the engine needs to be running. What a brilliant design! Had to drag the Tahoe on the ramp truck and a clever tow truck driver was able to shake the bed and use the ramp extension to drag it off at the dealer....along with a lot of WD40. The problem is a Fuel Pump Power Control Module. What next?

[Mark E.]

Re: Tahoe/Silverado Problem #2

I've never owned one, but have been told 2007-13 GM pickups without AFM are extremely reliable. And cheaper than a new one too.

[Mark F.]

Re: Tahoe/Silverado Problem #2

Excuse me, but what is
PSA
and AFM ?

[Mark E.]

Re: Tahoe/Silverado Problem #2

Public Service Announcement
Active Fuel Management (cylinder deactivation)

[Mark F.]

Re: Tahoe/Silverado Problem #2

we'll have to call this the "3-Marks" post
thank you for the definitions - I can be acronym-challenged...

as for the WD-40, I had to sell my Uncle's Mazda after he passed away and there were no keys to be found !
the flat-bed guy who came to pick it up for the buyer said NBD. He got out a gallon jug of Dawn (or some other detergent) spread it on the floor behind the wheels that were locked in park and winched it up onto the bed. Not ideal, but I had to get rid of it to sell his condo.

[Patrick H.]

Re: Tahoe/Silverado Problem #2

as for the WD-40, I had to sell my Uncle's Mazda after he passed away and there were no keys to be found !

FYI, for a Mazda, if you have proof of ownership (registration or title) the dealer can make you a key based on the VIN.

[Mark F.]

Re: Tahoe/Silverado Problem #2

FYI, for a Mazda, if you have proof of ownership (registration or title) the dealer can make you a key based on the VIN.

Thanks, Patrick
Wish I had known that back in 2007 when I had to sell his car...the guy who bought the car probably knew that, too
Anyhow, it was fairly well worn out, but it was a difficult sale to say the least w/o the keys . I was under the gun to get the property emptied, so I was in a weak negotiating position.

[Patrick H.]

Re: Tahoe/Silverado Problem #2

My last post on these vehicles had to do with the cylinder deactivation problem with my 2021 which resulted in a total top end tear down at 4500 miles.

I just redid the engine on my 2013 the 3 weeks prior to the National due to AFM lifter failure. It took 2 1/2 weeks and I finished it with a week to spare. It runs better than ever now.

The OEM's efforts to gain just a LITTLE bit on the CAFE measurements can cause us untold grief as owners.

[Mike M.]

Re: Tahoe/Silverado Problem #2

i bought a device that deactivates the 5.3L abc from switching to the 4 cylinder mode. about 100 bucks. mike

[Patrick H.]

Re: Tahoe/Silverado Problem #2

i bought a device that deactivates the 5.3L abc from switching to the 4 cylinder mode. about 100 bucks. mike

That's great...until a lifter fails and a cylinder permanently deactivates.
Theoretically that can (and will) still occur, you just avoid the day-to-day issues associated with AFM.

[Mark E.]

Re: Tahoe/Silverado Problem #2

That's great...until a lifter fails and a cylinder permanently deactivates.
Theoretically that can (and will) still occur, you just avoid the day-to-day issues associated with AFM.

My understanding is the 6.2 in this generation doesn't have AFM. A good reason to get the big engine.
.

[Patrick H.]

Re: Tahoe/Silverado Problem #2

My understanding is the 6.2 in this generation doesn't have AFM. A good reason to get the big engine.
.

I’m thinking the 3.0L diesel next time.
Same towing capacity, incredible fuel mileage.

[Richard M.]

Re: Tahoe/Silverado Problem #2

I’m thinking the 3.0L diesel next time.
Same towing capacity, incredible fuel mileage.

Patrick, I was thinking the same but opted for the 6.2L Ecotec3 gas version on my '20 Sierra AT4 10 Speed. I got it for towing a small 17' camper and my car trailer and didn't want to be restricted where to fuel up on my palm-bird summer round trips FL/NH/FL. The 6.2L Ecotech3 has DFM(Dynamic Fuel Management), "any" multiple cylinder deactivation. This has the same lifter issues as AFM(Active Fuel Management)8 to 4 cylinders only.

DFM & DSF(Dynamic Skip Fire) details Here.

When I tow, I set DFM off. There is no switch. The Range Device Dr Mike Mc uses for his 5.3L AFM is not compatible with the 10 Speed, only 6 or 8 speed.

For my truck, it is disabled by setting shifter to L9 in manual shift mode. Never reaches 10th gear which is fine. I get about 11 mpg towing 5k lbs(camper) to 7k lbs(encl car trailer), about 22 highway mpg not towing. Truck is rated to tow 9400 lbs. My 6.2L with optional cat back exhaust is 433hp 466lb/ft torque.

My understanding is the 6.2 in this generation doesn't have AFM. A good reason to get the big engine.
.

Mark I believe you're thinking of the '08-'13 Vortex 6.2L. However some had AFM as well. Good spec info Here.

6.2L Ecotec3 Specs Here

Rich

[Richard M.]

Re: Tahoe/Silverado Problem #2

I just redid the engine on my 2013 the 3 weeks prior to the National due to AFM lifter failure. It took 2 1/2 weeks and I finished it with a week to spare. It runs better than ever now.

The OEM's efforts to gain just a LITTLE bit on the CAFE measurements can cause us untold grief as owners.

Patrick on your '13 did you replace with stock AFM lifters or did you "upgrade" to non-AFM lifters?

Rich

[Patrick H.]

Re: Tahoe/Silverado Problem #2

Patrick on your '13 did you replace with stock AFM lifters or did you "upgrade" to non-AFM lifters?

Rich

All non-AFM LS6 lifters.
I was not going to leave any lifters in place that could still fail.
I had the computer reprogrammed to eliminate the AFM as well.