GMT900 Silverado, Sierra, Tahoe & Yukon (2007–2013)

The GMT900 — 2007 to 2013 Chevy and GMC full-size trucks and SUVs — refined the GMT800 but added one big headache: Active Fuel Management (AFM) and the lifter failures that come with it. This hub covers the AFM problem, engine choices, exhaust and intake, and the rest of GMT900 ownership. Comparing eras? See the GMT800 (1999–2006) and K2XX (2014–2018) hubs, or the LS Swap hub.

Latest GMT900 Content

Start here

• GMT800 vs GMT900: Which Generation to Buy

AFM lifter failure — the big one

AFM lifter failure is the single most common and most expensive GMT900 5.3L problem. Know the symptoms and your options before it grenades a cam.

• GMT900 AFM Lifter Failure: Symptoms, Cost, and the Permanent Fix
• AFM Delete Guide for the 5.3 Silverado

Engines & exhaust

AFM oil consumption and cylinder misfires are what put a GMT900 on a scan tool most often. Pull the code before you start buying parts — they are all covered in the Silverado trouble code index.

• 6.0 vs 8.1 Vortec
• 5.3 Ticking Noise Silverado: Diagnosis
• 5.3 Chevy Exhaust Sound: MagnaFlow Muffler — hear it and discuss on the forum
• Best Exhaust for the 5.3 Silverado
• Best Cold Air Intake for the 5.3 Silverado

Transmission & electronics

• 4L60E Common Problems
• Service StabiliTrak Silverado: Fix

Owner tools for your GMT900

Free, no sign-up, and built specifically for full-size GM trucks and SUVs.

• GM RPO Decoder — type the option codes off your glove box sticker, or photograph the label and let the page read it. Quickest way to confirm whether you have AFM, which axle you are running, and what the trim actually included.
• GM RPO Code Database — every option code we hold, searchable by code or by plain description, and filterable to your model year.
• MPG Calculator — miles, gallons, engine. You get your number and where it sits against everyone else running the same engine.

Still on the bench: a tire, gear and speedometer calculator for working out how far off your speedo reads after a size change and what it did to your effective gearing, and quick identifiers for engine RPO, axle code, transfer case and AFM/DFM — the things you need standing at a parts counter. See all FullSizeChevy owner tools →

Join the GMT900 discussion

Discuss your GMT900 in the FullSizeChevy forum → · Show off your NNBS build