BMW Serpentine Belt and Pulley Replacement, How To
BMW Serpentine Belt and Pulley Replacement, How To

100 thoughts on “BMW Serpentine Belt and Pulley Replacement, How To”

  1. Bavarian Autosport says:

    @chicoloco101 –
    While you may or may not "need" a new tensioner or idler pulley, it would certainly be wise to replace all of the pulleys. This will assure that you do not have a pulley failure at some point after replacing the belts. A faulty pulley can cause an annoying squeal and eventually will seize or come apart. This will result in loss of and damage to the belts …. as well as a full vehicle failure as the water pump and alternator will no longer be operating.

  2. tomas kantor says:

    how do you keep your engine so clean

  3. Bavarian Autosport says:

    Well ……… This particular car has 60k miles, has never driven in salt (winter roads) and we do clean under the hood regularly.

    While some would not agree, we do not have an issue with using the "quarter car wash" wand under the hood, along with cans of engine cleaner. Just be wise about what you are spraying.

  4. Bavarian Autosport says:

    Unfortunately, your car could have either system. You will need to make a visual inspection.

  5. Calcutta151 says:

    How about the a/c tensioner? I watched a well made vid only to see the a/c belt and tensioner omitted….

  6. doodo412 says:

    wow you just saved me a lot of money, thank you so much

  7. Bavarian Autosport says:

    If the pulley has any play or roughness when rotated … replace it. The further school of thought is to always replace the pulleys when replacing the belts. If a pulley seizes or gets too wobbly (loose), it will throw the belt, resulting is a road side tow and subsequent repair …. or damaged engine due to overheating.

  8. free palestine says:

    nice and clean, thank you so much

  9. voicetube says:

    Question: I have a 2002 330ci and have had an on and off high-pitched whine over the past few days (when it whines, it's full loudness and when it's not, car sounds fully fine It's always one or the other when start 'er up).

    When it's there, I turn engine off, engine comes to a complete stop yet the whine continues for a full second or two and THEN winds down. Any idea what it might be? (The idler pullys have stopped while the whine continues for a sec or two … and THEN slows).

  10. Bavarian Autosport says:

    You may have a vacuum leak in the intake system. This could be any of the intake boots, bellows, hoses, etc., or the crankcase ventilation oil separator and check valve. The leakage could also be in the fuel tank vent system. Obviously, without being there to diagnose it, there are certainly other possibilities. Have you gotten under the hood to try to localize the sound, when it happens? This should really be the next step. Feel free to call us at 800-535-2002, for further assistance.

  11. Bavarian Autosport says:

    We do not actually offer vehicle service at our NH headquarters. We can see that, with our knowledge, it would appear that we are servicing the vehicles. We did start into this business servicing and repairing BMWs, back in the '70s. We now operate the online, phone and catalog business. Our continued knowledge comes from still being enthusiasts and owning and driving these cars. Unlike some enthusiast oriented businesses, our employee parking is packed with BMWs and MINIs. 800-535-2002

  12. voicetube says:

    Thanks!! I'm guessing right now that it is (was actually – it's working fine now after 200 or so miles!) the secondary cooling fan (which is why it could keep sounding for a few seconds, after the engine was turned off). I'll have it looked at by my mechanic here in Dallas next oil change.

  13. Norman Singleton says:

    I really just wanted to say thank you this video was the shit …….i have a BMW 530I the only the diff was the fan shroud because the radiators hose is part of that assemble but after you get that out this video is 100% and way easy ….trust me i can believe to tell you the money i saved for about 2hrs of work thank you once again

  14. hondaguy453 says:

    This is awesome! Thank you very much!

  15. Bavarian Autosport says:

    The piston should not push all the way out of the cylinder. If it is, it needs to be replaced. We do have them in-stock at or call us at 800-535-2002

  16. Bavarian Autosport says:

    It may be "fine" as long as it is under compression (installed). But you should plan on a replacement.

  17. 14_07_22 says:

    What is this belt for

  18. Bavarian Autosport says:

    The main belt drives the water pump, alternator and power steering pump. The air conditioning compressor is on the smaller secondary belt.

  19. D Block says:

    At 2:25 I call BULL ISH!! I see they cut and edit the clip. Just a hammer will not get that fan off. Have to use some break free and let it soak for like 10 minutes. I know, I know, i'm not mad. Just saying that part is usually difficult. Be sure to put anti-sieze on the fan clutch nut so its easier next time when installing. EXCELLENT video though.

  20. Bavarian Autosport says:

    Yes, all of our videos are fully edited so we can show hours of work in a few minute video. We did indeed use the hammer to break this one free. In our overall experience, on many models, they do usually break free with a good crisp hammer hit. You typically do need the pulley holder tool, so that the pulley does not turn when you hit the hammer. If the pulley is held secure so that it cannot move, the hammer blow will do the trick most of the time. Just remember, the thread is left-hand.

  21. Anthony Salazar says:

    how would you do it on a hydraulic tensioner?03 325ci

  22. Bavarian Autosport says:

    Remove the plastic center cap on the tensioner pulley and use a Torx or hew bit (with a ratchet) to press against the hydraulic piston (in the same manner as shown for the mechanical tensioner).

  23. NutNbutSpeed says:

    My only gripe with this video is that I just noticed they removed the radiator hoses but they don't mention any of it on the video. Is it gonna make a huge mess and how do I prevent it? I understand you have to edit the video but that is critical not to mention someone as newbie as myself could really get into some deep trouble if I screw something up. Just some constructive criticism, no disrespect.

  24. Bavarian Autosport says:

    As noted in the video, you do not need to remove the radiator (or the hoses) in order to replace the belts and the pulleys. We removed them so that we could get a better view of the belts and pulleys with the video camera. We would normally only remove the fan and the fan shroud.

  25. chino3642 says:

    Is this Belt removal the same for a M50 motor?

  26. chino3642 says:

    I have the fan removal tools so it will be a sinch

  27. Bavarian Autosport says:

    The M50 will be very similar. Any differences will be more due to whether the engine has a mechanical tensioner (as shown in the video) or a hydraulic tensioner.

  28. matrix4583 says:

    is this the same way for the z4 engine?

  29. Bavarian Autosport says:

    What year and model Z4? If it has the M54 6-cylinder engine, yes it would be basically the same.

  30. matrix4583 says:

    it is 3.0si

  31. Bavarian Autosport says:

    You have the N52 engine. This is a different engine (M54 is shown) and the belt routing will be different, but the basic procedures will be similar.

  32. Brandt Selvig says:

    Would i be able to use any socket wrench set? And if you can please, what size socket exactly for the tensioner?

  33. Bavarian Autosport says:

    You will need at least a 3/8" drive socket set. However, a 1/2" drive set would be better, especially for detensioning the tensioner. The socket used for the detensioning in the video is 17mm. However, different models may have different sizes.

  34. matrix4583 says:


  35. hindflight R says:

    You guys did an excellent video, probably one of the best on youtube! However the OP to this question should note that there are some models with the M54 (such as 330ci) that will have an additional idler pulley positioned above the tensioner that the belt runs under. This pulley is often the source of bearing noise when worn. anyway, thanks BA I was able to complete this project his weekend thanks you!

  36. Bavarian Autosport says:

    Thanks for your notes. There are indeed, differences between specific engine models, in placement and use of idler pulleys as well as the differences in mechanical vs hydraulic tensioners.

  37. Brunosautoshop says:

    If doing it from the bottom then removing fan clutch is not needed ?

  38. Mike Kelly says:

    Thanks for this video, its been really useful.

  39. Joe Levesque says:

    How was it to remove the belt and tensioner with the additional idler? It seems that the idler is restricting access to the bolt for the upper tensioner. Is there a particular sequence to removing and assembling?

  40. Bavarian Autosport says:

    You shouldn't have any specific trouble in de-tensioning the belt by rotating the tensioner pulley against the tensioner. Once the pulley is rotated, pull the belt off of one of the pulleys and then release the pulley.

  41. hindflight R says:

    DeTensioning the belt was accomplished with a T50(60? can't remember) as shown here. The tensioner can be removed after the idler pulley was removed. If you're changing your tensioners, you might as well change the idler pulley as well. Assembly is the reverse of removal.

  42. Bavarian Autosport says:

    Sometimes. You'll have to take a look to see, on your model.

  43. raross6119 says:

    can you help with e36 m44 motor belt tensioner. this looks as ugly as it gets and there is no info anywere for this looks like you need to take the whole poer steering assembly off just to get to it

  44. Bavarian Autosport says:

    We don't have an M44 engine here to check for you. We seem to recall that the power steering pulley may need to be removed from the pump.

  45. Buzzy Beatz says:

    What is the difference between a idler pulley and a drive belt tensioner roller

  46. David Brown says:

    is this same way for a m50b20 bmw engine?

  47. soccer10083 says:

    How would you do this for a R56 MINI cooper S? My mechanic said it would be $500 or something ridiculous because he would have to move the turbo

  48. Bavarian Autosport says:

    Well, we're not sure just whet the mechanic may have had in mind, but the belt replacement certainly does not require removal of the turbocharger. The belt is accessed through the passenger wheel-well area. Remove the wheel, then remove the inner plastic shielding.

  49. Bavarian Autosport says:

    The M50 engine will be very similar. You may find that the tensioner assembly is hydraulic vs. the mechanical style shown here.

  50. Bavarian Autosport says:

    The idlers are "hard mounted" and direct the belt in order to apply additional torque to a driven pulley or to direct the belt to the next pulley. A tensioner pulley is spring or hydraulically mounted an "pushes" or "pulls" on the belt in order to keep the belt tight on the pulleys.

  51. bigoscdog says:

    I have a 2002 E53 3.0 M54. I want to replace the belts and tensioners, but would like to be thorough while the belts are off. I am going to also replace the water pump. What other parts/pulleys should I replace while its opened up?

  52. Daniel Fosha says:

    Can a mechanical tensioner fail and how would one know when it does? Can the pulley be replaced on a mechanical tensioner? I have a 95 325i. Thanks for the videos!

  53. Ron Tiemens says:

    EXCELLENT video. Abundantly clear. Used it  to quickly and easily change out the belts on my E34 today.

  54. Milan Novek says:

    its the same on a e46 316i m43 ???

  55. Philip Gilles says:

    Are there any torque specs to worry about with this process?

  56. mike richardson says:

    your video is clear and precise. i enjoy the videos. i have 2008 e60 bmw 528XI. do you have a video showing serpentine belt and water pump removal

  57. Gr8mate13 says:

    I replaced all of my pulleys and belts this Saturday just gone 14th/06/2014 . My car is 2002 530i MSport, virtually everything shown above is correct except when he slides out the fan cowling. At the bottom of the cowling there is several heaters hoses attached which you also need to un hook. Not disconnected
    I managed to slide it up high enough and twist it to right to get it all out the way without discoonecting those hoses, however you will need to disconnect the little black hose that attaches to the header tank on the right hand side of the top of the radiator. It is a bit awkward but then i simply laid the cowling back onto the engine allowing enough room to access the lot. Whole job took 1.5 hours taking my time. I only had to add a cup full of coolant afterwards. Works perfectly , used OEM parts and replaced all pulleys and belts

  58. Eugene Bruno says:

    Otto, can you give me instructions on changing the alternator and serpentine belt on a 2003 BMW 325 I? And also the tools I will need. I know you have a store. [email protected] thanks

  59. krystyna paprocka says:

    Wow I dound the video that u were asking about but I am not sure it will help u calling serpentine bmw chnages bejt

  60. martinitime1975 says:

    I love this channel, saved me so much money on repairs for my E46!

  61. exterminator2x2 says:

    tengo un bmw 325i 2003   abres la llave y le funciona todo el tablero pero no tiene marcha el motor  y le doy directo al motor de arranque y no prende
    que puede ser 

  62. BenDC85 says:

    for those of you who are JUST replacing the belts (and not the tensioners), this is a 5min job (maybe a 10min job if you work slowly).  
    The air filter box, and radiator fan/shroud, DO NOT need to to come off to get to the belts.  

    All you have to do is loosen the tensioners (16mm socket) and slip the belts off.

    And like he says in the video, take the lower (A/C) belt off first.  
    Once the A/C belt is off, loosen the second (main) tensioner and the main belt can be slipped around/past the fan and out.  
    The new belts can go back on in the reverse order, it is really that simple.  the only tools you will need is a 16mm socket wrench.

    (the A/C belt is easier to get to if you put the car on jacks and work from the bottom)

  63. Pierre B. says:

    HELP! HELP. where is the input turbine shaft sensor on 1999 BMW 328i. I'm trying to solve a P0715 code.
    I googled it but had no serious info.
    These videos are excellent.

  64. Marco Fekry says:

    Help Please,I have m50b20 engine on my E36..I have got a squeezing sounds coming from one of the belts..but it only sounds when the engine revenues down.!!!I
    I have checked the Belts with no cracks..
    I just wonder if it is the tension-er of the drive belt or something else!!!

  65. Kesisha Griffth says:

    i have a 2003 bmw 745li and i have problem with my belt  i change the belt 4 times and the idler and tensioner  but i found out that i have to use a belt from the dealer i can put a new belt on and  it will work good for about 2 weeks are 1500 miles  then it will start  squeezing again do you think i have to get a   tensioner pulley from the dealer 

  66. Irakli Kavsadze says:

    I have e39 with M52tu engine (double vanos engine) 523i
    I have a strange noise when I start the engine in the morning 
    After engine runs for 2 or 3 min the noise goes away. If I shutdown the engine and start it again noise does not come again. It comes only on the first time when the engine is cold.
    I made a video here it is
    noise is gone at 0:58 in the video
    What it might be? any pulley? belt? or something else? please help

  67. Peter S. says:

    …you said in video "the A/C tesioner was already replaced, so we will not be replacing it" ??????? REALLY? The one pulley tensioner I needed to see being replaced! Your Video is INCOMPLETE.

  68. Guillermo Arria-Devoe says:

    Great video, I am getting ready to perform the tensioner/belt replacements on my 2006 X3 and I was wondering what socket size is needed for the tensioner assembly mounting bolts. Thanks!

  69. Jomiah Bernard says:

    Gr8 video. Well done. Thanx. Have a 325i 2002 model, on mornings cold start and misfires. After a few minites it idlies fine . What is the cause of that?

  70. Jomiah Bernard says:

    Gr8 video. Well done. Thanx. Have a 325i 2002 model, on mornings cold start and misfires. After a few minites it idlies fine . What is the cause of that?

  71. stuarth43 says:

    why do you refer to hex head screws as bolts, a bolt is something with a nut, you can have hex head or socket head screws, the are all in the cat of CAPSCREW, which was a word used for bearing caps
    all these are screws
    thanks for info, but you let it all down by your terms

  72. Christophe Laurent says:

    Your video is great. Thank you

  73. Tyler Cothren says:

    How can I get one of your awesome Bavarian Autosport Red towel/mat things that are in all of your videos?

  74. Daniel Alvestrand says:

    thank you!

  75. Le San says:

    Awesome video thanks!

  76. mronemanband1 says:

    Nice video too bad you cant list a year & model  there are many BMW's

  77. clown tipsie says:

    i have an 528 i 1997 ..and my brother has the 1996 i have automatic and he has manual..we both have m52 engine only one strange thing he has two pulleys also one above the tensioner pully and i have only the tesioner pulley but not one above it like on video is this possible

  78. htc one says:

    I have a 2000 BMW 528i with a sports package and it looks the exact same as this one for putting it back together I don't know if it had or didn't have a idler like some pictures show but its lookes like this were there is none

  79. blackpassenger says:

    excellent vid. gonna be doing this to my 2000 320i here in tokyo

  80. Deano says:

    Really helpful, though it turns out I grenaded my PAS pump, so yeah bit more work to be doing.

  81. Derrick Brooks says:

    I changed my alternator on my BMW 545i 2005 and now I am getting active steering inactive on my dashboard and it hard to turn. what can I do need help. thanks

  82. matt gallagher says:

    Do you have the same video for the E83 SD Msport?

  83. ron romano says:

    You forgot to mention putting the block drain back in

  84. Trang Nguyen says:

    Thank you, this helps a lot

  85. Zachary Alcorn says:

    Was told need to replace belt and tensioner. Is the tensioner really need to be replaced $600 for a spring that got some oil on it? Would like to not replace old one if it looks good, but not sure if would be OK . Any ideas?

  86. ProSlam says:

    Why your BMW Z3 in your video do not have a idler pulley ?

  87. pgreenx says:

    These guys do the best videos.

  88. Cray Bal says:

    Help I have a 93 bmw 325i the engine won't turn over when I use the key, I had change the battery and the altinator but its still the same problem, when I jump start it the car the engine always turns over, but it won't start when I use the key and also when I leave the battery terminals on it drains the battery.

  89. David Monk says:

    The air conditioner belt tension pully , upper mounting bolt was removed in the beginning of the process. No where in the completion of the job, after belts replaced, does it show or say that that bolt (upper bolt on the air conditioning tension pully) needs to be replace. This is a very important step and was left out of the video,However, this video was very helpful and very much appreciated for me, not being a mechanic, saved me at least a couple hundred dollars. Thank you

  90. Bmw M3 e46 says:

    My car doesn't have an idler pulley

  91. MRXCHRISS says:

    do you recommend anti seize on the fan clutch nut? what kind would be best if any?

  92. jhrodriguez08 says:

    It's always so easy when you don't run into a seized fanclutch nut 😂

  93. Javier Garza Jr. says:

    You skipped ac belt..

  94. mgnum d says:

    thanks, great job

  95. Shawn Hill says:


  96. Paul Somlo says:

    Be glad that you have the hex head on the tensioner, rather than the Torx.

  97. S. T says:

    Wish you'd do one for elastic belts like on M57N.

  98. Timothy Gehring says:

    Do you have to change the tensioners and pulleys if ypur just changing the belts? Or can I just change the belts

  99. L. Thill says:

    I love YouTube, I was looking because a shop said I should replace my belts and wants $630 to do the job. they also want $260 to replace the fuel filter.
    I dont like doing the mechanics myself but these prices are insane for the amount of labor involved. I guess I will scratch them off my list and/or do it myself.

  100. Kisuk Yang says:

    Good voice and professional video. Excellent!

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