Vehicle

GMC Sierra

The full-size pickup, and a Chevrolet Silverado with different sheet metal and trim — the single most useful fact about any GMC. Same frame, same engines, same transmissions, same faults, and the Silverado's community is many times larger. Two systems on the petrol V8s decide how a misfire code should be read: cylinder deactivation, where a failed lifter produces a misfire that is neither ignition nor fuel, and the Duramax diesel's aftertreatment, which is read against load history rather than mileage.

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GMC Sierra Denali, front view — deathpallie325 · CC BY-SA 4.0 (external)

Generations

GMT400 1988–2000

The OBS trucks, sold as the Sierra Classic alongside their own successor for 1999 and 2000. Throttle-body injection to 1995, then the 1996 Vortec revision — sequential injection with new heads and camshafts — which is the division that matters whenever a part or a procedure is quoted for "a 5.7".
Body styles

Pickup

Platform

GM GMT400
Engines
4.3 V6 — LB4 · petrol · 112–123 kW (150–165 hp) · 312–319 Nm (230–235 lb-ft)

4.3 V6 Vortec 4300 — L35 · petrol · 149 kW (200 hp) · 346 Nm (255 lb-ft)

5.0 V8 — L03 · petrol · 130 kW (175 hp) · 359–366 Nm (265–270 lb-ft)

5.0 V8 Vortec 5000 — L30 · petrol · 172 kW (230 hp) · 386 Nm (285 lb-ft)

5.7 V8 — L05 · petrol · 138–157 kW (185–210 hp) · 400–420 Nm (295–310 lb-ft)

5.7 V8 Vortec 5700 — L31 · petrol · 190 kW (255 hp) · 447 Nm (330 lb-ft)

7.4 V8 — L19 · petrol · 172–190 kW (230–255 hp) · 522–549 Nm (385–405 lb-ft)

7.4 V8 Vortec 7400 — L29 · petrol · 216 kW (290 hp) · 556 Nm (410 lb-ft)

6.2 V8 diesel — LL4 · diesel · 94–112 kW (126–150 hp) · 325–380 Nm (240–280 lb-ft)

6.5 V8 diesel — L49 · diesel · 116 kW (155 hp) · 373 Nm (275 lb-ft)

6.5 V8 turbo diesel — L65 · diesel · 134–145 kW (180–195 hp) · 488–583 Nm (360–430 lb-ft)
Transmissions

4-speed SM465 manual · 5-speed HM290 manual · 5-speed NV3500 manual · 5-speed NV4500 manual · 5-speed 5LM60 manual · 3-speed THM-400 automatic · 4-speed 700R4 automatic · 4-speed 4L60 automatic · 4-speed 4L60-E automatic · 4-speed 4L80-E automatic

Drivetrain

Rear-wheel drive · Part-time four-wheel drive with low range
GMT800 1999–2007

The first Sierra on the LS-based small block, and the first with the 6.6 Duramax and its Allison gearbox in the heavy-duty trucks. The 8.1 big block and the Duramax are the two engines behind the six-speed manual.
Body styles

Pickup

Platform

GM GMT800
Engines
4.3 V6 Vortec 4300 — LU3 · petrol · 149 kW (200 hp) · 353 Nm (260 lb-ft)

4.8 V8 Vortec 4800 — LR4 · petrol · 201–213 kW (270–285 hp) · 386–400 Nm (285–295 lb-ft)

5.3 V8 Vortec 5300 — LM7 · petrol · 201–220 kW (270–295 hp) · 427–454 Nm (315–335 lb-ft)

6.0 V8 Vortec 6000 — LQ4 · petrol · 224–257 kW (300–345 hp) · 488–515 Nm (360–380 lb-ft)

8.1 V8 Vortec 8100 — L18 · petrol · 254 kW (340 hp) · 617 Nm (455 lb-ft)

6.6 Duramax LB7 — LB7 · diesel · 224 kW (300 hp) · 705 Nm (520 lb-ft)

6.6 Duramax LLY — LLY · diesel · 231 kW (310 hp) · 820 Nm (605 lb-ft)

6.6 Duramax LBZ — LBZ · diesel · 268 kW (360 hp) · 881 Nm (650 lb-ft)
Transmissions

5-speed NV3500 manual · 5-speed NV4500 manual · 6-speed ZF S6-650 manual · 4-speed 4L60-E automatic · 4-speed 4L65-E automatic · 4-speed 4L80-E automatic · 5-speed Allison 1000 automatic · 6-speed Allison 1000 automatic

Drivetrain

Rear-wheel drive · Part-time four-wheel drive with low range
GMT900 2007–2014

The Active Fuel Management era, and where the lifter question belongs.
- 4L80-E / 4L85-E 4-speed automatic
- Allison 1000 automatic
Body styles

Pickup

Platform

GMT900
Engines
4.3 V6 — petrol

4.8 V8 — LY2 · petrol

5.3 V8 — LY5 · petrol

6.0 V8 — petrol

6.2 V8 — L92 · petrol

6.6 Duramax V8 — diesel
Transmissions

Allison 6-speed automatic · 4-speed 4L80-E automatic · 5-speed Allison 1000 automatic

Drivetrain

Rear-wheel drive · Four-wheel drive
K2XX 2014–2019

Eight- and ten-speed automatics arrive; aluminium content increases.
Body styles

Pickup

Platform

GM K2XX
Engines
4.3 V6 — LV3 · petrol · 213 kW (285 hp) · 414 Nm (305 lb-ft)

5.3 V8 — L83 · petrol · 265 kW (355 hp) · 519 Nm (383 lb-ft)

6.2 V8 — L86 · petrol · 313 kW (420 hp) · 624 Nm (460 lb-ft)

6.6 Duramax V8 — diesel · 296–332 kW (397–445 hp) · 1037–1234 Nm (765–910 lb-ft)

6.0 V8 — LY6 · petrol

6.0 V8 — L96 · petrol · 268 kW (360 hp) · 515 Nm (380 lb-ft)
Transmissions

Allison 6-speed automatic · 6-speed 6L80 automatic · 6-speed 6L90 automatic · 8-speed 8L90 automatic · 6-speed Allison 1000 automatic

Drivetrain

Rear-wheel drive · Four-wheel drive
T1XX 2019–present

Dynamic Fuel Management — cylinder deactivation in seventeen patterns rather than one.
Body styles

Pickup

Platform

GM T1XX
Engines
4.3 V6 — LV3 · petrol · 213 kW (285 hp) · 414 Nm (305 lb-ft)

2.7 turbo four-cylinder — L3B · petrol · 231 kW (310 hp) · 472–569 Nm (348–420 lb-ft)

5.3 V8 — L84 · petrol · 265 kW (355 hp) · 519 Nm (383 lb-ft)

6.2 V8 — L87 · petrol · 313 kW (420 hp) · 624 Nm (460 lb-ft)

3.0 Duramax straight-six — LM2 · diesel · 207 kW (278 hp) · 624 Nm (460 lb-ft)

6.6 Duramax V8 — L5P · diesel · 332–350 kW (445–470 hp) · 1234–1322 Nm (910–975 lb-ft)
Transmissions

Allison 10-speed automatic · 6-speed MYC 6L80 Automatic · 6-speed 6L90 automatic · 8-speed 8L90 automatic

Drivetrain

Rear-wheel drive · Four-wheel drive

Information, not instruction

CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.

Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.

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