lcc014

I had bought both A/C and Accessories belts a while ago but too lazy to put them on until now. The accessories belt after 68k miles shows cracks.



For M54 engine, there is no way to replace the belts without taking out the fan. Therefore, I followed an UK memeber's instruction who did the thermostat change, to remove the fan. However, there are a few things which were not mentioned by that UK member when doing the fan removal. Maybe, UK model is different from US model.

I started by removing the 10 T30 metal screws to remove the metal cover above the radiator.

Center:


Driver side:


Passenger side:


T30 Screws:


Then I removed the plastic cover which is under the metal cover and above the radiator. There were 5 T25 screws. Take it easy when removing these 5 screws because you are dealing with plastic parts here.

Center screw hole:


Driver side screw holes:




Passenger side screw holes:

lcc014

Plastic cover off the car:


Then remove the small coolant hose on the plastic cover - 3 clips.

Now, the fan. According to the UK member instruction, there were 2 big clips in the bottom of the fan. That was true but half the story. There are 1 clip on the driver side of the fan, and 2 more clips on the passenger side of the fan.

Lower coolant hose clip, driver side:


Lower coolant hose clip, passenger side:




Coolant hose clip, driver side:


One of the 2 coolant hose clip, passenger side:




Driver side clip:



You need small hand to get to both coolant hose clips in passenger side. After that disconnect the fan connectors.





Now, the fun part to pull the fan up. There are 2 plastic "stop" on each side of the fan shroud. The one on the driver side is "movable". It needs to be turned away from the radiator hose when pulling the fan shroud up. The other "stop" on passenger side is fixed.

lcc014

Driver side fan shroud "stop":


It took me a while to pull up the fan shroud and had a tiny back pain .

With the fan shroud off, I could see a lots of leaves stuck in the gap between radiator and condenser.



There are also leaves in both sides of the power steering cooler.





I used T60 (as suggested by other member who replaced the belt in N52 engine) to release the tensioner of the A/C belt.





Just turn the tensioner clockwise, not much force is needed. A/C belt is still Okay. After removing the A/C belt, I used 16mm socket to release the tensioner of the accessories belt. This one needs more force to turn clockwise. I also used a drill bit to hold the tensioner in place.



I replaced both Accessories and A/C. One tip to put on the A/C is that belt on crankshaft first then route the belt over the compressor. I tried the other way, belt would not go into the crankshaft. Accessories belt was a bit easier, but I needed to remove the drill bit and turned the tensioner all the way clockwise to get the belt on it.

New A/C belt:


New Accessories belt:


Now, another fun part to perform belt change - to install fan shroud. It took me a while (more back pain) to put it back. The trick is to hold the fan shroud as close as possible (touching) to the radiator. Then slide it down while touching the radiator. You will encounter resistance on the driver side. You have to slide the fan shroud under the plastic part next to the radiator.



Above picture shows the plastic part next to the driver side coolant hose clip. Fan shroud has to goes under this plastic part. Once the fan shroud is half way down, you then hook coolant hoses back to the 5 clips around the fan shroud. Then "turned" the fan shroud "stop" on the driver side back such that it could go into the plastic slot on the side of the radiator. You will understand what I mean when you are doing this.

lcc014

I also took a picture of the radiator drain cock while I was in there.



These are the belts that I used :

A/C belt


Accessories belt


Putting everything back was just reverse the installation. Please do not over tighten the 5 plastic cover screws.

Hope this help other members to replace their belts in M54 engine.

lcc014

Here are the belt routing for A/C and Accessories belts:

A/C belt:


Accessories belt:


Hope this help.

JasonH

Great guide (I really should take more photos when I do jobs). My belts are at 70k miles and I think need doing soon so most helpful.

My UK diesel doesn't have a tensioner on the A/C so I'll have to wind/stretch the belt on... what fun.

lcc014

That will be some more work to do when putting the A/C belt back on.

ey2001

is this pretty much the same on a 525 2006? n52?

lcc014

Most likely they are similar but not exactly the same.

ray=out

i used this write-up as a reference for when i did my belt change on my 2004 525i (m54), and i just wanted to add a bit to a great DIY. i'm not sure what the differences are between the tensioners, but my car did not have a pin or torx bit arrangement on the alternator tensioner to relieve tension. i ended up having to take off the cover from the pulley and used a hex bit in the pulley bolt to release the tension.


thanks for this write-up.