Performance Radiator for GMC Envoy (2005-2009) 5.3L

All-Aluminum Heavy-Duty Radiator for 2005-2009 GMC Envoy

Direct Cooling Upgrade: Replaces fragile factory plastic-tank units with an all-aluminum downflow heat exchanger engineered to stabilize coolant temperatures under heavy towing and high thermal loads.

The Stock Envoy End-Tank Failure Point

Factory radiators in the GMT360 platform rely on crimped plastic end tanks bonded to an aluminum core. Over repeated thermal cycles and system pressure spikes, the composite tanks degrade, turn brittle, and split along the crimp seams. Additionally, high thermal dissipation demands during heavy towing rapidly expose the flow limitations of the stock core, leading to sustained heat soak and elevated transmission fluid temperatures.

The Engineering Solution

Engineered entirely from aircraft-grade AA5052 aluminum, this direct bolt-on radiator eliminates leak-prone composite plastics with 100% TIG-welded structural joints. The downflow core measures 18.11 in x 26.69 in x 1.02 in, utilizing an efficient multi-louvered fin array that accelerates heat rejection and prevents thermal runaway. It features an integrated transmission fluid cooler, a CNC-machined filler neck, and an included radiator cap, pressure-tested for zero-leak reliability.

Technical Specifications

Compatibility

• 2005-2009 GMC Envoy (5.3L V8 LH6)
• Note: Fits 5.3L V8 models only; does not fit 4.2L Inline-6 variants due to core dimension differences.

The GMC Towing Standard

Built to handle severe duty cycles, this all-aluminum cooling system protects your LH6 V8 and automatic transmission against thermal breakdown when hauling heavy payloads or traversing steep mountain grades.