BMW M54 Belt and Pulley Repair – 2004-05 E60 5 Series – M54 6 Cylinder

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bmw e60 belt repair pulley repair tensioner pulley

BMW M54 Belt and Pulley Repair – 3 Hours

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The BMW Repair Guide used this 2005 530i for the following article. To see other repairs on our site using this actual car, please click on the image below!

 

 

Repair Summary
The following article gives detailed instructions on performing a belt and pulley repair on a BMW E60 5 series car with the M54 six cylinder engine. Even though we have used a 2005 BMW 530i to perform this installation, this article can be applied to any BMW vehicle with the M54 six cylinder engine, including the E39 (5 series), E46 (3 series), E53 (X5), E83 (X3) and Z3 cars and SUVs. 

A BMW M54 belt and pulley repair will help cure one of the most annoying sounds you will encounter in your E60 5 series…the dreaded squealing sound from under the hood.

***Please note this repair is for the BMW E60 with the M54 6 cylinder engine with the mechanical accessory belt tensioner (please see below for more information on mechanical versus hydraulic belt tensioners). Other E60 models and engines may differ. Not sure which engine your BMW has? Use our realoem.com engine identification tool below.

This repair requires that you know which engine model you have in your BMW so you can order the correct parts. Not sure which engine model you have? The BMW Repair Guide uses realoem.com to verify all of their engine numbers. Simply click on the link below, enter the last seven digits of your BMW’s serial number (VIN number), and your engine model will be displayed along with other information concerning your vehicle.

Get my BMW engine model number

Unlike many of the BMW repairs we cover, belt and pulley squeal is simple to identify without the need of any fancy diagnostic equipment. You can hear it from 50 feet away; that embarrassing nerve grating squeal from under your hood that sounds like finger nails scraping on a chalkboard. The sound is a clear indication that your vehicle may require a belt and pulley repair.

The following video is what it sounds like on our 2005 530i E60 repair car:

The main accessory belt, or serpentine belt, on your BMW E60 serves the critical function of operating your alternator, water pump, and power steering pump. The second accessory belt, or a/c belt, operates the air conditioning compressor. As these belts age they become worn. The heat and stress put on them from the engine causes “dry rot”, a condition where the belt will actually start to crack. Belt and pulley squeal is the first indication that one of the belts are failing and is an extremely serious situation that should be fixed immediately. A broken main accessory belt can quickly cause catastrophic engine failure due to overheating.bmw e60 belt and pulley repair tensioner pulley serpentine belt

When replacing the belts on your BMW E60, it is also good practice to replace the two belt tensioner pulley assemblies and main idler pulley. The mechanical belt tensioner pulleys are responsible for keeping the belts taut so they do not slip or fall off. They are an integral part of the accessory belt system, and not replacing them is like changing your engine oil and not replacing your dirty oil filter.

Take the time to familiarize yourself with the following BMW M54 engine diagram showing the location of the belts and pulleys that need to be replaced.

bmw e60 belt repair pulley repair tensioner pulley

Please note that this repair article deals with the BMW M54 engine with a mechanical accessory belt tensioner. Many M54 six cylinder engines were produced with the “old style” mechanical belt tensioner for the main accessory belt.

“Old style” mechanical belt tensioner found on many M54 six cylinder engines.

The mechanical belt tensioner was later replaced with the updated, more reliable hydraulic belt tensioner.

Hydraulic belt tensioner
Updated hydraulic belt tensioner.

If you want to upgrade your mechanical belt tensioner with the newer hydraulic version during this repair, there is a very simple kit you can purchase to do this. We have provided a link to the kit in the parts section below for your convenience.

Parts, Tools and Supplies

Affiliate link disclosure – The BMW Repair Guide uses affiliate links in their site. For more information on affiliate links, please click here.

This repair requires that you know which engine model you have in your BMW so you can order the correct parts. Not sure which engine model you have? The BMW Repair Guide uses realoem.com to verify all of their engine numbers. Simply click on the link below, enter the last seven digits of your BMW’s serial number (VIN number), and your engine model will be displayed along with other information concerning your vehicle.

Get my BMW engine model number

Parts
This repair is for the BMW M54 six cylinder engine that uses a mechanical main accessory belt tensioner pulley (not the hydraulic). If you are not sure which main accessory belt tensioner pulley you have, please see our discussion above. If you have a mechanical tensioner pulley and would like to convert it to the more reliable hydraulic version, please see our parts list below to order a conversion kit.

1. Tensioner and idler pulleys (mechanical) (required) You will need to purchase a main accessory tensioner pulley (mechanical), an AC tensioner pulley and an idler pulley to complete this repair. If you would like to convert your mechanical main accessory pulley to hydraulic, please see part #3 below. If you already have a hydraulic accessory belt tensioner installed on your vehicle and need to replace it, please see part #4 below.

Part Quantity Part # Description
AC belt tensioner pulley – 12758 1 11287512758 OEM URO
Main accessory belt tensioner pulley – 27252 1 11281427252 OEM URO – mechanical tensioner pulley
Idler pulley – 16847 1 11287516847 OEM URO

 

2. Drive belts (required) Even if you have recently replaced them, we suggest replacing them again when servicing your pulleys. They only cost a couple bucks…that’s cheap insurance for avoiding catastrophic belt failure.

Part Quantity Part # Description
AC Belt – 31822 1 11287631822 Continental 4K843
Accessory Belt – 06545 1 11281706545 Continental 6PK1538

 

3. Hydraulic accessory belt tensioner conversion kit (optional) If you would like to upgrade your mechanical belt tensioner to the hydraulic version, then this is the kit for you. A hydraulic accessory belt tensioner is more reliable than the mechanical version, and can help avoid premature belt failure in your BMW E60 5 series vehicle.

Part Quantity Part # Description
Hydraulic tensioner pulley conversion kit – 797KT 1 11287838797KT ECS Tuning – complete kit to convert mechanical tensioner to hydraulic

 

4. Hydraulic belt tensioner (optional) Do you already have a hydraulic belt tensioner installed on your vehicle? You can still use this article to replace it. Please note – the hydraulic tensioner does not come with a new pulley…you must purchase it separately. We have included it below (it is the same “idler” pulley used in part list 1 above).

Part Quantity Part # Description
Main accessory belt tensioner – 38797 1 11287838797 OEM URO – hydraulic tensioner pulley
Idler pulley – 16847 1 11287516847 OEM URO

 

Tools and Supplies
Floor jack – low profile
Wheel Ramps
3/8″ hex key wrench (or alternatively T60 torx bit with Socket wrench – low profile flex head)
16mm socket wrench
T50 torx bit
Socket extensions
Torque Wrench
Socket drive adapter (optional)

Procedure

Section 1 – Removing the old belts and pulleys

  1. Jack and support the front end of your vehicle. You will need to get under the front of the car to access the AC belt and tensioner pulley. Not sure how to jack and support your BMW? Read our article on the simple and safest way by clicking here.
  2. The first belt to be removed from your vehicle is the AC accessory belt. You will need to remove the pressure being put on the AC belt by the belt tensioner pulley so the belt can be removed. There is a recessed torx (star) fitting on the front of the belt tensioner (see image below). Take a 3/8″ hex wrench, insert it into the torx fitting, and use your muscles to turn CLOCKWISE. The pulley will swivel downward allowing you to remove the belt. ***The reason we use a 3/8″ hex wrench instead of a torx bit is due to clearance issues in the engine compartment. Unless you have a special low profile ratchet or modified torx bit, you will not be able to get to the torx fitting using that combination. The 3/8″ hex wrench is easy and works perfectly!bmw e60 belt repair pulley repair tensioner pulleybmw e60 belt repair pulley repair tensioner pulleybmw e60 belt repair pulley repair tensioner pulley
  3. Using a 16mm socket wrench, remove the ac tensioner pulley mounting bolt. Remove the tensioner pulley from the car.bmw e60 belt repair pulley repair tensioner pulleybmw e60 belt repair pulley repair tensioner pulley
  4. Working from the top of the engine, find the main accessory (serpentine) belt tensioner pulley. This tensioner pulley is slightly different from the ac tensioner pulley – in order to release the belt pressure you will need to use a 16mm socket wrench instead of a hex wrench. There is a 16mm raised fitting on the front of the belt tensioner – use a 16mm socket wrench and turn clockwise to release the pressure on the main accessory belt. Grasp belt and remove from vehicle.bmw e60 belt repair pulley repair tensioner pulleybmw e60 belt repair pulley repair tensioner pulley
  5. The main accessory tensioner pulley is mounted to the front of the engine with two 13mm bolts, located on the top and bottom of the pulley assembly. The top bolt is easy to get to…unfortunately the lower bolt isn’t. It takes some trial and error, and a whole lot of patience, to get it out; try loosening it from the bottom of the engine and then removing it from the top. Everyone’s hand size and degree of flexibility is different, so it’s just a matter of finding the right angle to extract it. We used a 3/8″ 16mm socket wrench with a small extension to remove it…we found a 1/2″ drive socket wrench too large and clumsy.bmw e60 belt repair pulley repair tensioner pulley
  6. The final part that needs to be removed from the engine compartment is the idler pulley. If the pulley has its center dust cover on, remove it with a small metal pick. Use a T50 torx bit to remove the center mounting bolt. Please note that this bolt may be very tight and require the use of a breaker bar.

    One of the best tools you can have in your shop is a 24″ piece of 1″ galvanized pipe, purchased at any home improvement store. Simply slip it over the handle of a 3/8″ or 1/2″ ratchet and you have just created a great breaker bar that will free any stubborn bolt!

    bmw e60 belt repair pulley repair tensioner pulleybmw e60 belt repair pulley repair tensioner pulleybmw e60 belt repair pulley repair tensioner pulley

 

Section 2 – Installing the new belts and pulleys

    1. Installation of the new idler and tensioner pulleys is straight forward…just follow the steps above in reverse. Please note that the new tensioner pulley springs come pre-loaded out of the box – there is a pin holding them in the open position (DO NOT remove the pin yet) (see step 2b below). Torque all bolts to the following values: Tensioner Pulley – 18 ft-lb (24 Nm)
      Idler Pulley is 33 ft-lb (45 Nm)
  1. Once you have the three pulleys installed and torqued correctly, it is time to add the belts. Remember to always install the main accessory belt first…the AC belt is located on the outside of the engine and installed last.
    1. First, route the main accessory belt around and over all of the pulleys, as shown in the below diagram. Take your time and use patience…you are working in a confined space (if you get frustrated, take a break).
    2. The new belt tensioner pulley spring comes pre-loaded. In other words, there is a pin installed holding it in the “open” position so you can loop the belt over it.
    3. When you are satisfied you have the main accessory belt installed correctly over all of the pulleys, the final step is to remove the pin from the tensioner. This will require using both hands…one hand will turn turn the 16mm fitting clockwise to release pressure on the pin (just like in step 4 of the disassembly section above)….the other hand will remove the pin once the pressure is released. We know it sounds confusing, but it is actually quite simple. Watch the following video as we perform this procedure on our work bench:

bmw e60 belt repair pulley repair tensioner pulley

 

3. Install the AC accessory belt following the same directions in step 2 above.

 

BMW M54 Belt and Pulley Repair Finished
If you have any questions or comments, please feel free to contact us. And congratulations for Doing It Yourself!

The Repair Difficulty Level displays graphically how challenging the repair is, from easy to advanced. Easy repairs usually require very few tools, have short repair times and do not require jacking and supporting the vehicle. As the difficulty level rises, expect the repair to demand more time, specialized tools, and better understanding of mechanics to complete the job.
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