Tech Tip: Boom-Type Noise During Engine Warm-Up on Chevy Astro Vans – UnderhoodService

Tech Tip: Boom-Type Noise During Engine Warm-Up on Chevy Astro Vans

Some customers may comment on a boom-type noise heard in the vehicle passenger compartment during engine warm-up. To correct this, install an exhaust dampener assembly on affected vehicles. Use the following procedure and the part numbers listed in this Tech Tip.

Vehicles:
• 1996-2005 Chevrolet Astro Van
• 1996-2005 GMC Safari Van

Condition:
Some customers may comment on a boom-type noise heard in the vehicle passenger compartment during engine warm-up.

Correction:
Install an exhaust dampener assembly on affected vehicles. Use the following procedure and the part numbers listed below.

1. Raise and support the vehicle. Refer to the General Information subsection of the applicable service manual for information on lifting and jacking the vehicle.

Important: The exhaust dampener weight must face forward.

2. Position the exhaust dampener assembly on the catalytic converter pipe assembly approximately 90 mm (4 inches) forward of the outlet flange. See Figure 1.

3. Hand tighten the clamp nut and the dampener weight while maintaining the proper position. Install three 3/8” inside diameter and 1/16” thickness flat washers, part number 11509161, or equivalent between the top of the dampener and the heat shield plate.

Note: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

4. Install the 3/8-inch inside diameter lock washer, part number 11500046, or equivalent and jam nut. Tighten the clamp nut and the jam nut to 30 Nm (22 lb.ft.).

5. Lower the vehicle.

Technical service bulletin courtesy of Mitchell 1.

For additional information, visit www.mitchell1.com.

You May Also Like

Wallbox Announces Milestones in Acquisition of ABL

The company says the move has already paid off in the effort to support the EV transition.

Wallbox announced a number of milestones since its acquisition of ABL. According to the company, the move has already paid off in the effort to support the EV transition."We are immensely proud of what we have achieved in the first six months following Wallbox’s acquisition of ABL," said Jaume Ferre, Co-CEO of ABL and CTO of Wallbox. "The synergies between our companies have allowed us to move forward quickly with product integrations. We only expect this cadence to continue and to strengthen our ability to set new standards for innovation, reliability and customer experience."

Standard Motor Products Introduces 200 New Numbers

The release provides new coverage in 60 distinct product categories and 75 part numbers for 2023 and 2024 model-year vehicles.

Child Labor for Repair Shops

This could be a chance to introduce teenagers to the auto care industry.

Autel Energy Unveils Megawatt Charging System at ACT Expo

The MaxiCharger Megawatt Charging System is designed for heavy-duty electric trucks.

The Vital Nature of Multi-V Belt Systems

From the alternator to A/C, the multi-v belt uses a truck’s engine to operate crucial components. Here’s how to keep things running smoothly.

Other Posts

Mullen Continues Commercial EV Dealer Expansion in Midwest

New franchise partners Ziegler Truck Group and Range Truck Group will focus on the Pacific Northwest and upper Midwest regions of the U.S.

Non-Competes: A Non-Starter, Says FTC

The FTC’s rule is set to take effect in about four months, unless it is blocked by legal challenges.

Navigating The Legal Landscape with Succession Planning

Planning for a successful business handover means doing things by the book.

PRT Launches 59 New Complete Strut Assemblies

Extending PRT’s product portfolio in North America, the new release represents nearly 12M vehicles in new coverage.