Admission d'air froid pour moteur 5 cylindres 3,7 L Hummer H3 3T (2007-2012)

The Wrench Time

• Estimated Time: 45-60 Minutes
• Difficulty: 3/10 - Basic hand tools and straightforward bolt-on. The biggest hurdle on the 2007-2012 Hummer H3 3.7L is fighting the bulky factory resonator box.

Tools You Will Need

• 10mm Socket & Ratchet (For the battery terminal, airbox mounts, and heat shield bolts)
• 8mm Nut Driver or Socket (For factory and aftermarket hose clamps)
• T20 Torx Driver (Critical for removing the factory MAF sensor)
• Flathead Screwdriver (For popping harness clips and prying stubborn boots)
• Needle Nose Pliers (For compressing factory spring clamps on breather hoses)

Phase 1: Removing the Factory Part

1. Disconnect the Battery: Always start by disconnecting the negative battery terminal using a 10mm wrench to prevent check engine lights and reset the ECU’s fuel trims.
2. Unplug the MAF Sensor: Locate the Mass Air Flow sensor on the factory intake tube. Slide the red locking tab backward with a flathead screwdriver, press down on the black tab, and pull the harness free. Tuck the wire out of the way.
3. Loosen the Intake Clamps: Use an 8mm nut driver to loosen the hose clamp securing the intake tube to the throttle body, and the clamp securing the tube to the lower airbox.
4. Disconnect the Breather Hoses: Locate the hard plastic PCV breather hose running into the factory resonator. Pinch the grey or green locking tabs with your fingers (or gently with pliers) and pull the hose straight off. Be extremely gentle—this 2007-2012 factory plastic is highly prone to cracking.
5. Remove the Factory Resonator and Airbox: Grab the large factory resonator box sitting over the engine block and pull it straight up to pop it off its rubber mounting grommets. Next, use a 10mm socket to remove the bolts holding the lower airbox to the inner fender well, and lift the entire lower assembly out of the engine bay.

Phase 2: Installing the Cold Air Intake

1. Assemble and Mount the Heat Shield: Drop the aftermarket heat shield or new lower airbox into the factory mounting location. Secure it using the supplied hardware and a 10mm socket.
2. Transfer the MAF Sensor: Using your T20 Torx driver, carefully unscrew the factory MAF sensor from the old intake. Pull it straight out. Do not touch the delicate wire element inside the sensor! Insert the MAF sensor into your new intake tube, ensuring the airflow arrow points toward the throttle body. Secure it with the new supplied screws (do not reuse the coarse factory screws in a metal tube).
3. Mount the New Intake Tube: Slide the provided silicone couplers onto the throttle body and the new airbox adapter. Slide the aftermarket intake tube into the couplers. Hand-snug the worm-gear clamps. Once everything is aligned without binding, lock all clamps down tight with your 8mm nut driver.
4. Route the New Breather Line: Connect the supplied silicone breather hose from the engine’s PCV port to the new nipple on the aftermarket intake tube. Secure both ends with the provided clamps using pliers.
5. Final Connection and ECU Relearn: Reconnect the MAF sensor wiring harness and push the red locking tab back in. Reconnect the negative battery terminal with your 10mm wrench. Turn the key and start the engine. Do not touch the gas pedal for 20 seconds. Let the vehicle idle so the ECU can properly adjust to the new, higher volume of airflow.

Disclaimer: This is a general guide provided for the 2007-2012 Hummer H3 3.7L. Always refer to your factory service manual for exact torque specifications and safety procedures.