This thread will help you decide what pulleys you have and what to buy based on the setup of your particular car.
Begin!
For complete up to date write up of this exact blog as well as other amusing and funny blog postings and other bonus info, see my page here: Mango Definitive E46 Pulley Guide DIY - So you wanna replace your pulleys huh?
Your M5X and S54 engines have three belt-driven tensioner pulleys. The role of the tensioner is either to provide belt-spacing/traction and to quell crankshaft vibrations due to irregular accelerations from the crankshaft. This is done to prolong the life of belt-driven accessories and likely to quiet engine operation.
When should you replace your pulleys?
(Other engines such as the S50/S52 and S54 are same/similar. Even some Mercedes/Volvo engines use identical belt routing.)
Pulley 1:
There is only ONE part number that all E46s share (E36 S50 and S52 as well). There are some rare instances where some people have reported their car doesn't have this pulley. Always check before you buy!!
Notice the big nub sticking out of it:
Pulley 2: Main tensioner pulley. Your non-M E46 could have either a hydraulic tensioner or mechanical tensioner.
Look at your engine bay with a flash light and/or feel around the tensioner.
If you have this mechanical ROUND tensioner with HEX-shaped NUT sticking out of it like this:
You need the following: Dayco 89133 purchased at either Amazonian or your local Autozone. It may be under a different part number or name, but if you ask for an a/c tensioner for your E46, it will be the correct part.
This is how the Mechanical Tensioner Dayco 89133 pulley looks:
Pulley 3: A/C pulley.
If your A/C pulley uses a MECHANICAL tensioner as well, you'll again use the Dayco 89133 pulley:
This is the pulley all the way at the bottom. It's usually mechanical (haven't seen a hydraulic setup yet on the E46.) Just check yours to make sure by feeling with your hands or using a flashlight.
Remember: if the tensioner is round and has a hex-shaped nut sticking out of it, it's mechanical and you NEED the Dayco pulley.
Both types of tensioners use different pulleys.
Install tips:
If mechanical, you can use a 16mm or 5/8" socket turned clockwise to ease tension on the tensioner for purposes of removing the belt. Use an extension on your ratchet for extra leverage. Safely remove belt. Then insert appropriate torx or allen-head socket into actual tensioner bolt and turn counter-clockwise to remove bolt that holds the tensioner in.
If hydraulic, you use the bolt that goes through the tensioner to both relieve tension and remove the pulley.
BONUS:
If you want to change the ACTUAL tensioners themselves:
Hydraulic:
Mechanical:
OEM/Ina:
11287512758 (9/02+)
11281433571-1 (up to 9/02)
Common E46 setups: One alternator deflector pulley aka idler pulley, one hydraulic pulley for the main belt, one mechanical pulley for the a/c. (That's how my setup is on my 2002 330i)
Another setup I've seen is: One alternator deflector pulley aka idler pulley, and TWO mechanical pulleys (aka Dayco 89133 pulley) I've seen this on a 2004 330ci.
Your particular setup may vary!
If this has helped you, click on the star-rating at the top of the thread and rate it! 👏
Begin!
For complete up to date write up of this exact blog as well as other amusing and funny blog postings and other bonus info, see my page here: Mango Definitive E46 Pulley Guide DIY - So you wanna replace your pulleys huh?
Your M5X and S54 engines have three belt-driven tensioner pulleys. The role of the tensioner is either to provide belt-spacing/traction and to quell crankshaft vibrations due to irregular accelerations from the crankshaft. This is done to prolong the life of belt-driven accessories and likely to quiet engine operation.
When should you replace your pulleys?
- If your pulleys are original: replace them.
- If you don't know how old they are: replace them.
- If they are noisy or have excess play: replace them.
- If they have 60,000 or more miles: replace them.
(Other engines such as the S50/S52 and S54 are same/similar. Even some Mercedes/Volvo engines use identical belt routing.)
Pulley 1:
There is only ONE part number that all E46s share (E36 S50 and S52 as well). There are some rare instances where some people have reported their car doesn't have this pulley. Always check before you buy!!
Notice the big nub sticking out of it:
Pulley 2: Main tensioner pulley. Your non-M E46 could have either a hydraulic tensioner or mechanical tensioner.
Look at your engine bay with a flash light and/or feel around the tensioner.
If you have this mechanical ROUND tensioner with HEX-shaped NUT sticking out of it like this:
You need the following: Dayco 89133 purchased at either Amazonian or your local Autozone. It may be under a different part number or name, but if you ask for an a/c tensioner for your E46, it will be the correct part.
This is how the Mechanical Tensioner Dayco 89133 pulley looks:
Pulley 3: A/C pulley.
If your A/C pulley uses a MECHANICAL tensioner as well, you'll again use the Dayco 89133 pulley:
This is the pulley all the way at the bottom. It's usually mechanical (haven't seen a hydraulic setup yet on the E46.) Just check yours to make sure by feeling with your hands or using a flashlight.
Remember: if the tensioner is round and has a hex-shaped nut sticking out of it, it's mechanical and you NEED the Dayco pulley.
Both types of tensioners use different pulleys.
Install tips:
If mechanical, you can use a 16mm or 5/8" socket turned clockwise to ease tension on the tensioner for purposes of removing the belt. Use an extension on your ratchet for extra leverage. Safely remove belt. Then insert appropriate torx or allen-head socket into actual tensioner bolt and turn counter-clockwise to remove bolt that holds the tensioner in.
If hydraulic, you use the bolt that goes through the tensioner to both relieve tension and remove the pulley.
BONUS:
If you want to change the ACTUAL tensioners themselves:
Hydraulic:
Mechanical:
OEM/Ina:
11287512758 (9/02+)
11281433571-1 (up to 9/02)
Common E46 setups: One alternator deflector pulley aka idler pulley, one hydraulic pulley for the main belt, one mechanical pulley for the a/c. (That's how my setup is on my 2002 330i)
Another setup I've seen is: One alternator deflector pulley aka idler pulley, and TWO mechanical pulleys (aka Dayco 89133 pulley) I've seen this on a 2004 330ci.
Your particular setup may vary!
If this has helped you, click on the star-rating at the top of the thread and rate it! 👏