BMW E63 Belt Replacement – 2004-2010 6 Series – N62 8 cylinder

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1119
BMW E63 Belt Replacement – 1 Hour
Basic level repair
Repair cost level 1
The BMW Repair Guide used this 2005 645ci for the following article.
Repair Summary
The following article gives detailed instructions on replacing the drive belts in a BMW E63 6 series car with the N62 8 cylinder engine. Even though we have used a 2005 BMW 645ci to perform this installation, this article can be applied to any vehicle with the N62 8 cylinder engine with minor modifications.

A BMW E63 belt replacement should be performed at the first signs of wear on the accessory or AC drive belts.

Two of the most important components under the hood of your BMW 6 series vehicle, and often the least maintained, are the drive belts that power your engine’s mechanical accessories. The mechanical accessories include the water pump, alternator, power steering pump and air conditioning compressor.

The BMW N62 8 cylinder engine has two drive belts, both of which are driven by the crankcase pulley (harmonic balancer); the main accessory belt (also known as the “serpentine” belt) and the AC belt. The main accessory belt powers the water pump, alternator and power steering pump. The AC belt, as the name implies, powers the air conditioning compressor.

The two drive belts on your N62 8 cylinder engine are subjected to brutal conditions over the span of their lifetime. Extreme engine heat, pulley friction and stress take their toll on engine belts causing them stretch and crack. Oil leaks and other engine fluids can contaminate drive belts, weakening them and causing them to slip on the pulleys. A broken main accessory belt will shut down the water pump and power steering system, effectively making the car undriveable.

A BMW E63 belt replacement is a relatively simple repair for the home mechanic. It is important to note that on all 6 series vehicles produced from 2004-2010, BMW used a “stretch” AC belt to drive the air conditioning compressor. A stretch belt does not use mechanical tensioners, but rather is installed onto the AC pulley with a special tool (please see our tool list below for ordering). The stretch belt was also used on other BMW models with the N62 8 cylinder engine, including the E60 5 series and E65 7 series (production date from 10/2003). For those readers using this article to repair a model without a stretch belt, we have also included instructions for replacing an AC drive belt with the traditional mechanical tensioner pulley.

Many home mechanics with a stretch belt on their N62 engine have expressed interest in reverting to the mechanical tensioner system (stretch belt delete). It is a very easy and inexpensive switch to make. If you are interested in learning more about deleting your AC stretch belt and replacing it with a belt tensioner, please read our article BMW N62 AC Belt Tensioner Retrofit – Stretch Belt Delete  before starting this repair.

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1. Main accessory belt (required) The main accessory belt powers the water pump, power steering pump and the alternator on the BMW N62 8 cylinder engine. The following are two quality choices based on personal preference and budget.

Accessory belt – Continental 11287539831

All BMW models with the N62 8 cylinder engine.

Accessory belt – Genuine BMW 11287631817

All BMW models with the N62 8 cylinder engine.

2. AC belt (required) – There are two different types of AC belts, depending on whether your vehicle uses a “stretch” or tensioner system. As a general rule of thumb, all BMW E60 5 series (8 cylinder), E63 6 series, and E65 7 series cars (production date from 10/2003) use a stretch belt. All early E65 7 series (production date to 10/2003) and E53 X5 4.4 vehicles use a belt tensioner system. Always visually check your engine before ordering to confirm which system you have.

AC belt – Continental 11287512971

All BMW models with N62 8 cylinder engine using a belt tensioner system

AC belt – Continental 11287520177

All BMW models with N62 8 cylinder engine using a "stretch" belt system

Stretch belt installation tool

T50 torx bit

T60 torx bit

Socket wrench – 24″ extra long

Shears – heavy duty

Screwdriver – flat blade

Section 1 – BMW E63 belt replacement – removing the old belts.
The accessory belt can be easily replaced from the top of the engine compartment. You will have to get under the front of the vehicle to replace the AC belt. As discussed at the beginning of this article, some model BMWs use a stretch AC belt in place of a belt tensioner. We give instructions on replacing both systems below.

  1. Jack and support the front of the vehicle. If you are not sure how to do this, please see our article BMW Jacking and Supporting for Repairs and Maintenance.
  2. Looking down inside the N62 engine compartment, identify the main accessory drive belt on the front of the motor.bmw E63 belt replacement - Identify the accessory belt at the front of the engine.
  3. Use a small flat blade screwdriver or metal pick to remove the dust cap off of the tensioner pulley.bmw E63 belt replacement - Remove the dust cover from the tensioner pulley.
  4. Using a T50 torx bit and a long handle ratchet (or breaker bar), turn the tensioner pulley clockwise to release the pressure on the main accessory belt.Turn the tensioner pulley clockwise to release the pressure on the accessory belt.
  5. With the tension released, remove the belt from the water pump pulley. Remove the belt from the engine compartment.bmw E63 belt replacement - Slip the belt off of the water pump pulley.bmw E63 belt replacement- Remove the accessory belt from the engine.
  6. Moving underneath the front of the car, identify the AC drive belt. It will either be a stretch belt or use a tensioner pulley, depending on the year of production and/or model of your vehicle.
    BMW E63 belt replacement - locate the AC belt under the car.
    N62 engine with a “stretch” AC drive belt.
    BMW E63 Belt Replacement - AC belt tensioner pulley
    N62 engine with an AC belt tensioner.
  7. Stretch AC belts (belts with tensioner, see step 8) – Use a pair of heavy duty shears to cut the AC belt and remove it from the vehicle.BMW E63 belt replacement - cut the AC stretch belt with a pair of heavy duty shears and remove from the engine compartment.
  8. AC belts with tensioner – Using a T60 torx bit, rotate the belt tensioner counter clockwise to release its pressure on the AC drive belt.Remove the AC belt from the pulleys. bmw E63 pulley replacement - Use a T60 torx bit to turn the tensioner counter clockwise to release the pulley.

 

Section 2 – BMW E63 belt replacement – installing the new drive belts

Installing the new drive belts on models with a tensioner pulley is easy…just follow the above steps in reverse. Models with a stretch AC belt require several different steps. We show you both ways below. If you are interested in replacing your stretch AC belt with a tensioner system, please see our article BMW N62 AC Belt Tensioner Retrofit – Stretch Belt Delete before continuing.

  1. Stretch AC belts (belts with tensioner see step 2) – Loop the new AC belt around the crankshaft pulley (harmonic balancer). Partially install the belt on the bottom of the AC compressor pulley using the stretch belt installation tool to hold it in place (see image below). Using a long handled ratchet and a 24mm socket, slowly turn the crankshaft clockwise pulling the stretch belt onto the AC compressor pulley. Make sure to remove the stretch belt tool when you are finished. Check the belt to make sure it is aligned correctly on all pulleys…a misaligned belt can snap causing engine damage.bmw e63 belt replacement - stretch belt installation toolLoop the stretch belt under the AC pulley and hold in place with the installation tool.bmw e63 belt replacement - Use a long socket wrench to turn the crankshaft pulley bolt.Turn the crankshaft pulley bolt clockwise to pull the stretch belt onto the ac pulley.
  2. AC belts with tensioner -Using a T60 torx bit, rotate the tensioner counterclockwise to retract the pulley. Loop the new AC belt around both the crankshaft pulley and the ac compressor pulley then release the pulley. Check the belt to make sure it is aligned correctly on all pulleys…a misaligned belt can snap causing engine damage.bmw E63 belt replacement - Use a T60 torx bit to turn the tensioner counter clockwise to retract the pulley.
  3. Install the new accessory belt, making sure it is routed correctly. Pay careful attention to where it loops around the power steering and deflection pulleys…this can be confusing.Reinstall the accessory belt, making sure it is routed correctly.
  4. Using a T50 torx bit, turn the accessory belt tensioner clockwise retracting the pulley. Loop the accessory belt over the tensioner pulley then release it into its operational position.bmw E63 belt replacement - Turn the accessory belt tensioner clockwise to retract the pulley.BMW E63 belt replacement - Loop the accessory belt around the tensioner pulley and release it to its operational position.
  5. Check the belt to make sure it is seated correctly on all of the pulleys.

 

Final Notes
Always check, then double check, to make sure the belts are correctly lined up on the pulleys. A belt that is partially off of a pulley can snap causing engine damage. Start the vehicle and let it idle for a minute. Take the car for a spin around the block, then give the belts one more final check to make sure they are seated correctly on the pulleys.

 

BMW E63 Belt Replacement Finished
If you have any questions or comments, please feel free to contact us. And congratulations for Doing It Yourself!