Related Audi S8 Timing Belt Replacement for 4.2L 40 Valve Engine

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What to replace while changing the Audi S8 timing belt on the 4.2L 40 valve engine.

Audi S8 Timing Belt Replacement Diagram 4.2L
IMAGE DESCRIPTION Apart from the timing belt, the Audi A8 4.2L 40 valve engine's timing belt system consists of 5 serviceable timing belt components. One is the water pump that is driven by the timing belt. Second is the eccentric idler bearing, located on the driver side mid area of the engine block. Third is the small upper idler bearing on the passenger side cylinder head. Fourth is the timing belt tensioner with lever unit, which works in sync with the hydraulic tensioner damper providing the appropriate tension to the timing belt system.

Before going through the significant work of taking your car apart for timing belt replacement, please consider the following:

Looking To Save Money... "Can I Just Replace the Timing Belt?" Simply changing the 4.2L Audi S8 timing belt isn't enough. Why? Around the timing belt service interval (75,000 miles), due to age the integrity of the tensioner(s), damper, water pump, and other seals and o-rings are at the end or very near the end of their service life. Some individuals make the mistake of only replacing the timing belt. Then, 10,000-20,000 miles later, their new timing belt fails due to tensioner, idler bearing, or water pump failure.

Tensioners

Why replace your Audi S8 4.2L timing belt tensioners during timing belt service? Just as the timing belt has a designated service life and subsequent change interval, so do the tensioners and idler bearings. It's true that timing belts can get old, begin to crack, and eventually fail. However, it is just as common for the timing belt tensioners and/or idler bearings to fail, thus causing timing belt failure.

How can the tensioners cause a timing belt to fail? Most tensioner bearings contain a set amount of grease behind the seal. This grease provides ample lubrication and ensures tensioner reliability for the designated life span (75,000 miles). During engine operation, constant thermal temperature fluctuations eventually cause the bearing's grease to breakdown and loose it's lubricating properties. Over time, this results in unwanted bearing play and eventual seizure. If a timing belt tensioner has too much play or seizes, the timing belt can become misaligned, or begin to 'burn up' and shred, causing engine failure. Thermal temperatures also affect the timing belt causing the material composition of the belt to change and accelerates it's life span, often resulting in premature failure.

Water Pump

Why replace your V8 Audi S8 water pump during timing belt service? It makes sense from a labor standpoint since timing belt dis-assembly is required for water pump replacement. The water pump is driven by the timing belt and contains an internal sealed bearing that has a life span similar to the timing belt, tensioner, and idler bearings. The internal bearing and seals of an Audi water pump can weaken and is the primary reason why a water pump eventually fails.

Thermostat

Why replace your 4.2L V8 Audi S8 thermostat during timing belt service? The thermostat and housing is located behind the timing belt on the passenger side of the engine. It makes sense from a labor standpoint, since timing belt dis-assembly is required for thermostat replacement. The engine temperature is controlled by the thermostat. Near the end of it's designated service life the thermostat spring temper changes. This causes the thermostat to open too much allowing the engine to run cooler, resulting in poor fuel optimization, decreased fuel economy, and less horsepower.

Cover Gaskets & Cam Chain Tensioner Gaskets

Why replace your Audi S8 valve cover gaskets and cam chain tensioner gaskets during timing belt service? Audi S8 Valve Cover Gasket Replacement KitLeaking S8 cam chain tensioner gaskets are the most common oil leak, producing a foul burning oil smell in your interior. It makes sense from a labor standpoint to replace them during timing belt service, since timing belt dis-assembly is required for proper cam chain tensioner gasket replacement. Replacing them together will save you precious time and hundreds of $$$ of costly labor charges.

Audi S8 Timing Belt Replacement Kits

NEW! BLAU OFFICIAL O.E.tm INA Audi S8 Timing Belt Kits for 4.2L 40 Valve Engine

2001 Models with Early VIN

2001 engines had a VIN split with two different timing belt tensioner possibilities. 2001 owners will also need to confirm their VIN #. This kit is for the early VIN system, up to VIN 010500. How To Decipher Your Audi VIN Number.

  • Base INA Audi S8 Timing Belt Kit 4.2L

    INA Base Audi Timing Belt KitBASE

    Preassembled BASE INA Kit:
    • INA Gates Audi S8 Timing Belt
    • NTN Audi S8 Timing Belt
      Tensioner and Lever
      w/ Genuine Hardware
    • NTN Audi S8 Timing Belt
      Hydraulic Tensioning Damper
      w/ Genuine Hardware
    • INA Audi S8 Timing Belt
      Tensioner Eccentic Idler
      w/ Genuine Hardware
    • INA Audi S8 Timing Belt
      Tensioner Idler
      w/ Genuine Hardware
    • Timing Belt Service Interval
      Sticker

    Buy Audi S8 Timing Belt Kit Base

    Preassembled BASE kit comes directly from our partner Schaeffler who has been manufacturing timing belt components under the Official O.E. INA brand for decades. These kits include the same manufactured brand of timing belt and timing belt tensioner(s), the same ones that were fitted on your car from the factory.
  • Enhanced INA Audi S8 Timing Belt Kit 4.2L

    INA Enhanced Audi Timing Belt KitENHANCED

    Preassembled BASE INA Kit:
    • INA Gates Audi S8 Timing Belt
    • NTN Audi S8 Timing Belt
      Tensioner and Lever
      w/ Genuine Hardware
    • NTN Audi S8 Timing Belt
      Hydraulic Tensioning Damper
      w/ Genuine Hardware
    • INA Audi S8 Timing Belt
      Tensioner Eccentic Idler
      w/ Genuine Hardware
    • INA Audi S8 Timing Belt
      Tensioner Idler
      w/ Genuine Hardware
    • Timing Belt Service Interval
      Sticker

    Other Components:
    • Graf Audi S8 Water Pump
      w/ Metal Impeller and Gasket
    • Audi S8 Thermostat w/ O-Ring
    • Audi S8 Flennor Gates
      Serpentine Belt
    • Front Crank Seal
    • Camshaft Seals

    also included...

    Blauparts Extras
    • Allen Bolts for Lower
      Crankshaft Pulley
    • Thread Locking Compounds
    • Anti Seize Compound
    • Blauparts Detailed Step-by-Step
      Audi S8 4.2L Timing Belt
      Instructions - Numerous pages
      and images of detailed step-by-
      step guidelines, including front
      bumper removal.

    Buy Audi S8 Timing Belt Kit Enhanced
  • Enhanced Plus INA Audi S8 Timing Belt Kit 4.2L

    INA Enhanced + Audi Timing Belt KitENHANCED +

    Preassembled BASE INA Kit:
    • INA Gates Audi S8 Timing Belt
    • NTN Audi S8 Timing Belt
      Tensioner and Lever
      w/ Genuine Hardware
    • NTN Audi S8 Timing Belt
      Hydraulic Tensioning Damper
      w/ Genuine Hardware
    • INA Audi S8 Timing Belt
      Tensioner Eccentic Idler
      w/ Genuine Hardware
    • INA Audi S8 Timing Belt
      Tensioner Idler
      w/ Genuine Hardware
    • Timing Belt Service Interval
      Sticker

    Other Components:
    • Graf Audi S8 Water Pump
      w/ Metal Impeller and Gasket
    • Audi S8 Thermostat w/ O-Ring
    • Audi S8 Flennor Gates
      Serpentine Belt
    • Front Crank Seal
    • Camshaft Seals
    6 Liters German Ravenol G12   Plus Antifreeze (4 - 1.5L Bottles)

    also included...

    Blauparts Extras
    • Allen Bolts for Lower
      Crankshaft Pulley
    • Thread Locking Compounds
    • Anti Seize Compound
    • Blauparts Detailed Step-by-Step
      Audi S8 4.2L Timing Belt
      Instructions - Numerous pages
      and images of detailed step-by-
      step guidelines, including front
      bumper removal.

    Buy Audi S8 Timing Belt Kit Enhanced +

2001 Models with Later VIN

2001 engines had a VIN split with two different timing belt tensioner possibilities. 2001 owners will also need to confirm their VIN #. This kit is for the later VIN system, and VIN's that are after 010501 . How To Decipher Your Audi VIN Number.

2002-2003 Models

2002-2003 model years had only one timing belt system option. Owners will NOT need to confirm their engine code or VIN #.

  • Base INA Audi S8 Timing Belt Kit 4.2L

    INA Base Audi Timing Belt KitBASE

    Preassembled BASE INA Kit:
    • INA Gates Audi S8 Timing Belt
    • NTN Audi S8 Timing Belt
      Tensioner and Lever
      w/ Genuine Hardware
    • NTN Audi S8 Timing Belt
      Hydraulic Tensioning Damper
      w/ Genuine Hardware
    • INA Audi S8 Timing Belt
      Tensioner Eccentic Idler
      w/ Genuine Hardware
    • INA Audi S8 Timing Belt
      Tensioner Idler
      w/ Genuine Hardware
    • Timing Belt Service Interval
      Sticker

    Buy Audi S8 Timing Belt Kit Base

    Preassembled BASE kit comes directly from our partner Schaeffler who has been manufacturing timing belt components under the Official O.E. INA brand for decades. These kits include the same manufactured brand of timing belt and timing belt tensioner(s), the same ones that were fitted on your car from the factory.
  • Enhanced INA Audi S8 Timing Belt Kit 4.2L

    INA Enhanced Audi Timing Belt KitENHANCED

    Preassembled BASE INA Kit:
    • INA Gates Audi S8 Timing Belt
    • NTN Audi S8 Timing Belt
      Tensioner and Lever
      w/ Genuine Hardware
    • NTN Audi S8 Timing Belt
      Hydraulic Tensioning Damper
      w/ Genuine Hardware
    • INA Audi S8 Timing Belt
      Tensioner Eccentic Idler
      w/ Genuine Hardware
    • INA Audi S8 Timing Belt
      Tensioner Idler
      w/ Genuine Hardware
    • Timing Belt Service Interval
      Sticker

    Other Components:
    • Graf Audi S8 Water Pump
      w/ Metal Impeller and Gasket
    • Audi S8 Thermostat w/ O-Ring
    • Audi S8 Flennor Gates
      Serpentine Belt
    • Front Crank Seal
    • Camshaft Seals

    also included...

    Blauparts Extras
    • Allen Bolts for Lower
      Crankshaft Pulley
    • Thread Locking Compounds
    • Anti Seize Compound
    • Blauparts Detailed Step-by-Step
      Audi S8 4.2L Timing Belt
      Instructions - Numerous pages
      and images of detailed step-by-
      step guidelines, including front
      bumper removal.

    Buy Audi S8 Timing Belt Kit Enhanced
  • Enhanced Plus INA Audi S8 Timing Belt Kit 4.2L

    INA Enhanced + Audi Timing Belt KitENHANCED +

    Preassembled BASE INA Kit:
    • INA Gates Audi S8 Timing Belt
    • NTN Audi S8 Timing Belt
      Tensioner and Lever
      w/ Genuine Hardware
    • NTN Audi S8 Timing Belt
      Hydraulic Tensioning Damper
      w/ Genuine Hardware
    • INA Audi S8 Timing Belt
      Tensioner Eccentic Idler
      w/ Genuine Hardware
    • INA Audi S8 Timing Belt
      Tensioner Idler
      w/ Genuine Hardware
    • Timing Belt Service Interval
      Sticker

    Other Components:
    • Graf Audi S8 Water Pump
      w/ Metal Impeller and Gasket
    • Audi S8 Thermostat w/ O-Ring
    • Audi S8 Flennor Gates
      Serpentine Belt
    • Front Crank Seal
    • Camshaft Seals
    6 Liters German Ravenol G12   Plus Antifreeze (4 - 1.5L Bottles)

    also included...

    Blauparts Extras
    • Allen Bolts for Lower
      Crankshaft Pulley
    • Thread Locking Compounds
    • Anti Seize Compound
    • Blauparts Detailed Step-by-Step
      Audi S8 4.2L Timing Belt
      Instructions - Numerous pages
      and images of detailed step-by-
      step guidelines, including front
      bumper removal.

    Buy Audi S8 Timing Belt Kit Enhanced +