Ignition Coil and Iridium Spark Plugs for Hummer H3T (2009-2010) 3.7L

Direct-Fit Ignition Coil and Iridium Spark Plug Kit for 2009-2010 Hummer H3

What it Does: The Ignition Coil and Iridium Spark Plug Kit restores secondary ignition energy and consistent flame-front propagation on the 2009-2010 H3 to eliminate cylinder misfires and restore lost engine performance.

The Stock Hummer H3 Secondary Ignition Breakdown

In the cramped bay of the GMT345 chassis, continuous thermal cycling severely degrades factory coil-on-plug modules. Over time, internal micro-arcing compromises the primary and secondary copper windings, while thermal fatigue breaks down the dielectric epoxy resin and silicone plug boots. Compounding this, standard nickel-core spark plugs suffer from accelerated electrode erosion, increasing the plug gap and demanding higher dielectric breakdown voltage. This results in erratic spark delivery, unburnt hydrocarbon build-up, catalyst degradation, and persistent P0300-P0305 random misfire diagnostic trouble codes under load.

The Engineering Solution

Engineered as a synchronized drop-in refresh, this kit pairs reinforced pencil ignition coils with ultra-fine-wire iridium spark plugs. The coils utilize premium copper wire with upgraded internal magnetic lamination and high-grade dielectric potting to resist heat soak, electrical leakages, and mechanical vibration. Paired with laser-welded iridium center electrodes, this package significantly lowers the required ionization voltage, ensuring crisp arc stability, optimal combustion efficiency, and precise throttle response across the entire powerband.

Technical Specifications

Compatibility

• 2009-2010 Hummer H3 Base 3.7L L5
• 2009-2010 Hummer H3 Adventure 3.7L L5
• 2009-2010 Hummer H3 Luxury 3.7L L5
• 2009-2010 Hummer H3T Base 3.7L L5
• 2009-2010 Hummer H3T Adventure 3.7L L5

Frequently Asked Questions

Does this fit the GMT345 H3?
Yes, this is a direct fit for the 2009-2010 Hummer H3 and H3T equipped with the 3.7L LLR inline-five engine.

Are the iridium spark plugs pre-gapped for the Atlas 3.7L?
Yes, they are factory gapped to OEM specifications, though checking gap clearance prior to installation is always recommended.

The Hummer Heavy-Duty Trail Standard

Built to handle extreme trail conditions, high ambient thermal loads, and heavy utility demands, this complete ignition service pack provides dependable spark stability and sustained low-end torque retention on and off the pavement.