Vehicle
Hummer H3
The small one, on the GMT355 platform shared with the Chevrolet Colorado and GMC Canyon — so those are where its information lives. The 3.5 and 3.7 straight-fives are the engines most have, and they are unusual enough to be worth naming: an inline five with a cylinder-head casting that developed a known cracking history between the valve seats, which produces coolant loss and misfire codes on an engine that otherwise reads healthy. The Alpha's 5.3 V8 is a different proposition and shares none of that.
Generations
-
First generation 2005–2010
GMT355, shared with the Colorado and Canyon; the straight-five's head cracking between the valve seats is the fault behind most of its coolant and misfire codes.
- Body styles
- SUV · Pickup
- Platform
- GMT355
- Engines
-
- 3.5 five-cylinder — L52 · petrol · 164 kW (220 hp) · 305 Nm (225 lb-ft)
- 3.7 five-cylinder — petrol · 178–180 kW (239–241 hp) · 327–328 Nm (241–242 lb-ft)
- 5.3 V8 — LH8 · petrol · 224 kW (300 hp) · 434 Nm (320 lb-ft) · H3 Alpha
- Transmissions
- 5-speed Aisin AR5 manual · 4-speed 4L60-E automatic
- Drivetrain
- Part-time four-wheel drive with low range
Information, not instruction
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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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