Dorman 674-391 Driver Side Exhaust Manifold Kit Instruction Manual

1. Introducció

This manual provides detailed instructions for the installation, operation, maintenance, and troubleshooting of your Dorman 674-391 Driver Side Exhaust Manifold Kit. This precision-engineered and durably manufactured exhaust manifold is designed to match the fit and function of the original manifold on specified vehicles, ensuring reliable performance and a complete repair.

Image: Dorman Exhaust Manifold Kit, highlighting components for a complete repair.

2. Compatibilitat del vehicle

The Dorman 674-391 Driver Side Exhaust Manifold Kit is compatible with the following vehicles. Always confirm fitment using your vehicle's make, model, and trim level before installation.

• Chevrolet C2500 Suburban: 1996, 1997, 1998, 1999
• Chevrolet C2500: 1996, 1997, 1998, 1999, 2000
• Chevrolet C3500: 1996, 1997, 1998, 1999, 2000
• Chevrolet C3500HD: 1996, 1997, 1998, 1999, 2000
• Chevrolet Express 3500: 1996, 1997, 1998, 1999, 2000
• Chevrolet K2500 Suburban: 1996, 1997, 1998, 1999
• Chevrolet K2500: 1996, 1997, 1998, 1999, 2000
• Chevrolet K3500: 1996, 1997, 1998, 1999, 2000
• Chevrolet P30: 1996, 1997, 1998, 1999
• GMC C2500 Suburban: 1996, 1997, 1998, 1999
• GMC C2500: 1996, 1997, 1998, 1999, 2000
• GMC C3500: 1996, 1997, 1998, 1999, 2000
• GMC C3500HD: 1996, 1997, 1998, 1999, 2000
• GMC K2500 Suburban: 1996, 1997, 1998, 1999
• GMC K2500: 1996, 1997, 1998, 1999, 2000
• GMC K3500: 1996, 1997, 1998, 1999, 2000
• GMC Savana 3500: 1996, 1997, 1998, 1999, 2000

3. Què s'inclou

Your Dorman 674-391 Driver Side Exhaust Manifold Kit includes the following components for a complete repair:

• 1 x Dorman Driver Side Exhaust Manifold
• Required Gaskets (for manifold to cylinder head and manifold to downpipe)
• Required Downpipe Hardware (bolts, nuts, studs)

Image: All components of the Dorman 674-391 Driver Side Exhaust Manifold Kit.

4. Informació de seguretat

ADVERTÈNCIA: aquest producte conté productes químics coneguts per l’Estat de Califòrnia que provoquen càncer i defectes congènits o altres danys reproductius.

Always prioritize safety when working on your vehicle. Professional installation is recommended. If performing installation yourself, adhere to the following safety guidelines:

• Utilitzeu l'equip de protecció individual (EPI) adequat, incloent-hi ulleres de seguretat, guants i protecció auditiva.
• Assegureu-vos que el vehicle estigui ben recolzat sobre gats o un elevador abans de treballar a sota.
• Allow the engine and exhaust system to cool completely before beginning work to prevent burns.
• Disconnect the vehicle's battery before starting any electrical work or major component removal.
• Work in a well-ventilated area to avoid inhaling exhaust fumes or other hazardous vapors.
• Use the correct tools for each step to prevent injury and damage to components.

5. Guia d'instal·lació

This section outlines the general steps for replacing an exhaust manifold. Specific procedures may vary by vehicle model. Refer to your vehicle's service manual for precise torque specifications and detailed instructions.

5.1. Preparació

1. Aparqueu el vehicle en una superfície plana i activeu el fre d'estacionament.
2. Deixeu que el motor es refredi completament.
3. Desconnecteu el terminal negatiu de la bateria.
4. Raise the vehicle safely using a lift or jack stands.
5. Locate the driver side exhaust manifold.

5.2. Removal of Old Manifold

6. If applicable, disconnect any oxygen sensors or other components attached to the manifold.
7. Remove the bolts connecting the exhaust downpipe to the manifold.
8. Remove the bolts securing the manifold to the cylinder head. These may be seized due to heat and corrosion; use penetrating oil if necessary.
9. Carefully remove the old exhaust manifold and any old gaskets.
10. Clean the mating surfaces on the cylinder head and downpipe thoroughly to ensure a proper seal with the new gaskets. Remove any carbon buildup or old gasket material.

5.3. Installation of New Manifold

11. Place the new manifold-to-cylinder head gasket onto the cylinder head studs (if applicable) or align it with the bolt holes.
12. Position the new Dorman exhaust manifold onto the cylinder head.
13. Install the manifold-to-cylinder head bolts. Hand-tighten them initially.
14. Install the new manifold-to-downpipe gasket and connect the downpipe to the manifold using the provided new hardware. Hand-tighten.
15. Following your vehicle's service manual, tighten the manifold-to-cylinder head bolts to the specified torque in the correct sequence.
16. Tighten the manifold-to-downpipe hardware to the specified torque.
17. Reconnect any oxygen sensors or other components that were disconnected.
18. Baixeu el vehicle.
19. Torneu a connectar el terminal negatiu de la bateria.
20. Start the engine and check for any exhaust leaks. Listen for unusual noises.

6. Principis de funcionament

The exhaust manifold is a critical component of your vehicle's exhaust system. Its primary function is to collect exhaust gases from multiple cylinders and direct them into a single pipe, leading to the catalytic converter and then out through the muffler. This process is essential for efficient engine operation and emissions control. A properly functioning exhaust manifold ensures optimal gas flow, reduces back pressure, and minimizes exhaust leaks, which can affect engine performance and fuel economy.

7. Manteniment

While exhaust manifolds are designed for durability, regular inspection can help identify potential issues early:

• Inspecció visual: Periodically inspect the manifold for visible cracks, rust, or signs of exhaust leaks (e.g., black soot around joints or flanges).
• Listen for Leaks: A ticking or tapping sound, especially when the engine is cold, can indicate an exhaust leak.
• Comprovació dels elements de fixació: Ensure all bolts and nuts securing the manifold and downpipe are tight. Over time, heat cycles can cause them to loosen.
• Emissions System Check: If your vehicle has an integrated catalytic converter, ensure it is functioning correctly as part of your regular emissions checks.

8. Solució De Problemes

Common issues related to exhaust manifolds and their potential solutions:

9. Especificacions

10. Garantia i assistència

Dorman is committed to providing high-quality replacement parts. Your Dorman exhaust manifold is backed by the following warranty:

• Conventional Manifolds: Backed by a lifetime warranty against defects.
• Manifold Converters (if applicable): Guaranteed for 5 years or 50,000 miles.

For technical support, warranty claims, or further assistance, please visit the official Dorman Products website or contact their customer service directly. Always have your product model number (674-391) and vehicle information ready when seeking support.

Visita DormanProducts.com for more information and to find the correct application for your vehicle.