2005 VW Jetta TDI belt noise and alternator decoupler pulley replacement

[@danoriron4975]

This is how ALL repair videos should be. You have a keen insight to teaching, the camera techniques are great, and the editing truly helps people understand what’s going on during the process. Wish I had videos like this when I was younger. Learning the ‘hard way’ can be quite costly.

[@ThePracticalMechanic]

Thank you very much!!!!! Some of my videos are time consuming to create and positive reinforcement keeps the fire lit. Thanks again for watching.

[@inspector7144]

😅😅😅

[@genie121]

Omg mine was making noise since June! I wanted to cry lol. For months I'd put the radio on loud to avoid the noise. Just had a car service and they replaced this for me. Now she drives like a dream.

[@chibluth]

one of the best instructional videos I have seen, brilliantly explained, and the amount of detail you imparted was second to none . Many thanks for taking the time to explain the nuances of this set up. Just going out to test mine as its making some unhealthy noises :)

[@ThePracticalMechanic]

Thank you!!!! Sometimes the tensioner fails on its own but most of the time it ends up needing the alternator pulley. Some of these engine have a more complicated belt routing but the job will be nearly identical.

[@rogerlucas1733]

Beautiful video! I appreciate you going slowly and thoroughly thruout. So many others just gloss over several steps

[@ThePracticalMechanic]

Glad it was helpful!

[@hayzeproductions7093]

See i was a bit concerned about the belt tentioner vibrating thinking the speing was failing. To find posts about the alternator pully failing as a common issue. I was under the impression i would need to get a new alternator. However seeing this video gives me a much better insight on if i need to fix or replace any pully parts. Your video was truely helpful! And i learned a few things from this video tonight. Definately bookmarking this for future reference.

[@tedjohnson64]

Fascinating video! I’ve watched hundreds of car repair videos over the years, but have never seen this failure/fix scenario before! Also, the video lighting and narration were also extremely well done. Cheers!

[@jamiedutton8721]

Great video, tried to replace mine last year with no joy, watched your video and learned about the tensioner pin! Still struggled with getting the pulley to start loosening but once it started it was a piece of cake. No more vibrations, no more rattling, no more squeaky steering. Thanks for the vid 👍

[@TimothyChandawira]

I have this problem on my 06 Audi A3 1.9tdi, the belts makes so much noise, was really dissapointed when i got a new tensioner coz it didnt change anything and only this morning whilst reversing in the driveway, the alternator decoupler pulley seized and fell off. Upon investigating the tensioner, i realised i could replace the coupler pulley. After fitting another 2nd tensioner again this morning i realised the noise problem is still there and that got me searching on youtube and im glad i found this video

[@ThePracticalMechanic]

I’m not gonna lie the first time I came across this I replaced the tensioner. It was good for about a week and started rattling again, ended up being the pulley. Now I always check the alternator pulley when checking out belt noises.

[@CanadianDrifter777]

Great video all around! Showing in detail how the 2 tools attach to pulley/shaft was really helpful. Nice touch with the mirror view. Thanks!

[@spelunkerd]

What an interesting repair. You had me scratching my head regarding the clockwise method to spin the tensioner off. My first thought was that it is left handed, but not so! You're spinning the alternator shaft from 'behind', meaning that the pulley bearing is threaded onto the shaft with right hand threads.... Like turning the workpiece to thread on a bolt, you spin the opposite way!

[@felipesolanet7469]

Very good video. I have to do this same repair in my car's alternator and none of the other videos showed the details and with the clarity that this video does. Thank you for sharing this.

[@NicsElectronics]

My Jetta along with the mods and "maintenance" have turned me into an ASE certified mechanic haha

[@ThePracticalMechanic]

Hands on training is sometimes the best way to learn. Back that up with some theory and the ASE cert tests aren’t too bad.

[@glasser2819]

then you're ready to upgrade to a Porsche 👍🏻

[@shanks_1908]

Thank you so much for this. I was literally about to go buy another belt tensioner pulley before I watched this video. Going to check the alternator pulley now 👍

[@LewChaney]

Excellent video. Very understandable. The symptoms on my 2013 2.5L PASSAT are the same as yours before the repair. Thanks so much for sharing your time and knowledge on this.

[@abudabidibibudi]

respect ! i have the belt on my mk4 golf ca 200.000km and stil going ok :P nice german inginering ! helo from Montenegro

[@dillon7773]

Good lad no stupid music just clear instructions thank you 😎

[@333oberon]

Perfect demonstration of a check. Thank you.

[@hypnoblizxzx2606]

Much respect for using the correct tool to de thread the Pully I just put a wrench in there and wedge it in lmao “welcome to backyard mechanics”

[@harrisdoesthings]

Holy, I didn't know about that pin to hold the tensioner!! Here I am trying to do this one handed, jeepers.

[@ThePracticalMechanic]

I used to fight them as well until I replaced the first tensioner and it came pined in the released position. Kept the pin and use it all the time.

[@harrisdoesthings]

@@ThePracticalMechanic hopefully this is the cause of my start up rhythmic belt whine which changes with RPM and goes away after 5mins.. Would you have any knowledge around this?

[@ThePracticalMechanic]

It can cause a whine or chirping noise if the alternator pulley is is trying to lock up and then releases. Sometimes the whining noise can be cause the alternator itself when it try’s to recharge the battery after startup. You may want to pickup a cheap stethoscope from harbor freight and see if you can tell where the whine is coming from. I would then pull the serpentine belt off and see if the noise goes away. This confirms that the problem is indeed in the belt drive system. Is you have a gasoline model the noise could be from secondary air injection pump as well. I had a passat in the shop a few days ago that had turbo whine for about 3minutes after startup as well.

[@bugattieb110ss]

Bloody superb video my friend. The best i've seen.

[@JorgeCastillo-rd7cc]

gracias; por compartir estos buenos conceptos y la herramienta adecuada; para el reemplazo correcto de la polea altrnador

[@Dicky-the-Driver]

Absolutely top notch video and instructions.

[@grahamwishart4832]

Easy peasy if the access allows you to do this... usually end up having to remove alternator and use impact wrench or long spanner to crack pulley off rotor spindle

[@bryanlamontagne2914]

@ 3:20 can you use a drill bit instead of a pin?

[@ThePracticalMechanic]

Bryan Lamontagne sure!!! A drill bit or an Allen wrench will work great but sometimes drill bits are too long to fit in there.

[@mygtisfastr]

Great video ill changing my pulley belt and tensioner

[@ThePracticalMechanic]

Great!!! Did you pickup the tools for the pulley?

[@jocelyntoussaintj241]

What tools need to take out altenateur pulley?

[@samdavinchi1624]

Thanks for the video. So I understood that the rattling noise is because of bad pulley. What about squeaky noise in idle when cold engine.?

[@markorakonjac1364]

Why is the tensioner still vibrating so much at the end of the video? I have replaced all pulleys and put a new serpentine belt along with a new tensioner. However, the tensioner is vibrating just like in this video, and it makes a fairly loud hissing noise. The mechanic says it's normal but doesnt seem normal to me. I've seen a few videos of this engine where the tensioner barely moves, this is the first video in which the tensioner vibrates just like mine.

[@ThePracticalMechanic]

I find the vibration at the end to be normal on most of the TDI's. At the beginning it was vibrating so bad it was rattling or knocking.

[@ignaciobarcia1549]

What an amazing video! No circus music or ai voices and can't be clearer! I did replaced the tensioner recently and the rattle comes and goes still, if anything a bit stronger perhaps because of the new tensioner? The question is.. In my case if I rev the car ever so slightly to say 900rpms the rattle dissappears immediately. Would you or any follower say this is l consistent with a bad alt. Pulley?

[@ThePracticalMechanic]

Still quite possible. The engine speed is more consistent above idle so the belt will smooth out.

[@Crumble787]

I thought that if the tensioner was wiggling at all it meant that it was going out. I’m new to car repair so I’m just figuring it out. The after video is what a properly operating tensioner is supposed to look like?

[@ThePracticalMechanic]

The automatic belt tensioner a like in the video will always wiggle a little bit and diesel VWs seem to wiggle more than most. The tensioner at the beginning was shaking so bad it would cause a rattling noise at times. After fixing the alternator pulley the tensioner returned to a normal condition.

[@Crumble787]

@@ThePracticalMechanic thanks for replying! That clears up my confusion.

[@xobk]

Could a bad alternator pulley like this cause flickering headlights and stutter in power steering?

[@starlite3597]

I am sure you are supposed to do this by turning the 32 spline nut counter clockwise, and at same time holding the triple square. would make sense as the spline on the pulley is stronger than the spindle?. would love to know you're thoughts on this? thanks

[@starlite3597]

??

[@jagvolvo33]

looks like you can do it both ways BUTTT you have to turn it clockwise first to unsieze/unlock first then turn it anti clockwise by hand to "wind"it off.

[@unnikrishnan7913]

Very well demonstrated. Kudos

[@JJT331]

Thanks for the info. Worked out great.

[@alfonsosierra406]

Hoping you can reply to me as this was the easiest simplest most effective video I seen about this issue. My question is, will this work on a VW cc sport 2011 2.0tsi?

[@thabohendrick1021]

Hello. Is that a double sided fan belt. Because mine, the lines faces the clutch pulley. 🤔

[@ThePracticalMechanic]

Yes. Some of these had double sided belts.

[@thabohendrick1021]

@@ThePracticalMechanic ooohhhh this is new to me where i stay i saw single sided

[@lorettamckee208]

What if rpm needle is jumping and sounds like my car is coughing squeak coming engine

[@gbrmoto263]

Are these same style pulleys on the 2.0 tdi bkd as I have the same noise ?

[@FaceTigers]

Thank you for the video .. very helpful !

[@AK-sv4kb]

On a 1.6 tdi the idler pulley has some sideways movement( left to right). I do have some weird electrical issues which couldn't be sorted. I'm wondering if this could be the issue. Any tips?

[@dand7056]

I stripped the torx bit part and couldn't get it off. Does that mean I need a whole new altenator now? This was not as easy as this video for me. I have 2013 passat tdi. Can I somehow still use this altenator, or did I ruin it?

[@ThePracticalMechanic]

It may still be possible to remove the pulley from the alternator with an impact wrench. This may require alternator removal but may keep you from needing a complete replacement.

[@jagvolvo33]

@@ThePracticalMechanic if he takes it off the car ,does he then just put the impact wrench on the "spline" tool and wiz it off ANTIclockwise without having to lock anything ??

[@techoutsider2801]

Mine turns but not as easily as yours. Should I still replace it? For example, I can not spin it with just my fingers and the tool like you can. I have to use a wrench to give me more leverage to make it spin. (Not a crazy amount. Just a little)

[@johnstewart4749]

Hi have u got the link to get the soling bit for to tak alt pulley off

[@bakaerammutla7855]

does this also apply to a 2008 Audi A4 B8 petrol? I have cnaged the tensioner and still noise

[@ThePracticalMechanic]

It will apply to some but not all of them. You may need to inspect the alternator pulley and see if it is the same style as in the video.

[@bakaerammutla7855]

will do and inform you after checking

[@glasser2819]

plastic idlers with dry bearings can develop excessive freeplay - This all contributes to killing the expensive accessories from bearings death. Tensioner itself is engineered to wear out in *3* ways: - Lose of *dampener* friction - Loose arm *bushing* - loose ball *bearing* Minimal Tune Up: - *idler* set - *tensioner* assembly - New quality *belt*

[@LeonSkipiol]

Size tool are you using or is it universal size (adapter ) 33 teeth

[@durnadal1]

Can this also happen on a 2.0l mk6 version of this vehicle? I seem to have the noise issue I cannot figure out

[@1.9tdilove71]

Very good video my friend. Hi from India. I have 2006 skoda Octavia 1.9 tdi alh diesel 5 speed manual clocked 100k. There is little rattle grinding type of sound coming from gearbox side . Clutch is normal soft , gear engagement normal. Mechanic is saying use it and no urgent repair need. Should I do clutch overhaul? Should I change clutch plt pressure plt release bearing and flywheel? Which brand luk or sachs I should opt? Also which brand timing kit I should opt for? INA or contitech? Thank you bro

[@fridagylterud9491]

A rattle? I’ve had that on my 1,9 tdi, we installed a new flywheel and the noise went away. If your clutch feels normal then you don’t need a new one

[@1.9tdilove71]

@fridagylterud9491 yes. My clutch is normal soft, gear engagement normal, pickup is Also normal . Only thing is little rattle when cold, when I press the clutch, noise disappears and when release, little noise. Can it be of release bearing and flywheel only?

[@fridagylterud9491]

@@1.9tdilove71 sounds like a bad flywheel, mine also made a rattle noise when idling and when I pressed the clutch the noise went away, so maybe you have the same problem as me. Try replacing the flywheel first 👌 could be release bearing too but if your clutch feels normal it’s more likely that your flywheel is bad

[@fridagylterud9491]

@@1.9tdilove71 to sum it up, if your clutch feels normal and good, you don’t have to replace it, It’s supposed to feel soft. If the rattle noise is the only thing, it’s very likely that it’s just your flywheel making a noise. And to know wether you need luk or sachs flywheel, you have to know what kinda clutch you’ve got

[@1.9tdilove71]

@fridagylterud9491 Thanks mate for your kindness. Highly appreciated. Thnx

[@tylerb7795]

Thank you Do you have a source that you prefer for the purchase of the pulley?

[@RedondoBeach2]

I appreciate this video. The links provided show a few options for necessary tools. Would you recommend the specific tools you have over the others or would you say the others might have an advantage over the set featured in this video? Also, is the Hazet decoupler socket a high quality tool or just a good tool? Do you have an opinion on the triple squares you have compared to SnapOn's version? Finally, my MKIV GTI VR6 has 136K miles and the original pulleys. Am I pushing the limits of the pulley's life, and the life of the alternator at this point? Unsure how long each typically lasts on a MKIV GTI 2.8L VR6 or even a MKIV GTI 1.8L. Thanks in advance for your feedback.

[@bestbuildpc]

What is the torque specification? Thanks for sharing!

[@grahamwishart4832]

Usually 85 Nm ...

[@keithsmigielnpdc6547]

I have a 2015 jetta 2.0 and i am having same issue. However, I changed the tensioner and alternator and having the same issue. Could it be the power steering pump pulley or the A/C they only 2 left LOL

[@DanTheManIOM]

does the 2.5 tensioner have a pin too ? I replaced it since I stripped the pulley bolt and the belt is loose, I screwed up something....

[@ThePracticalMechanic]

Yes. Almost all of the tensioners come shipped with a pin installed

[@DanTheManIOM]

@@ThePracticalMechanic ok, I will go look. A year ago, I replaced one on a subaru, it had a pin. I don't recall seeing one...

[@Genic1981]

great video, very helpfull, thanks

[@julianescamilla2667]

Good video but the belt tensioner is still bouncing all over the place, is that normal? or a bad tensioner spring that needs to be replaced?

[@ThePracticalMechanic]

They will always bounce some. If it is bouncing enough to here a rattle then something is wrong with the tensioner or the alternator pulley.

[@xshahid1987x]

Superb video pal 👌🏼

[@johngonzalez1193]

So does the 18 piece basic kit provide everything you need? It looks like it..

[@ThePracticalMechanic]

Yes the 18 pc kit has the tools to do the VWs and several other makes.

[@TryDiy]

Great instructional video.

[@jamesmarshalsea9916]

Hey great video 📹 very helpful but all the items listed in the video arnt available on amazon now did you have any names of what the sockets are called ?

[@ThePracticalMechanic]

No problem. With current supply issues many of my linked items are unavailable. There are probably alternatives if you search for VW decoupler socket

[@jamesmarshalsea9916]

@@ThePracticalMechanic thank you very much for geeting back to me very helpful 😀 keep up the good work mate 👍

[@johnstewart4749]

And the new part ur puting on u got a link to it plz

[@antoinej.8910]

Is there any way to get rid of the normal rattle noise that you mention at 7:07 ? It’s extremely annoying at times.

[@ThePracticalMechanic]

Sometimes a new tensioner will resolve the slight rattle as the spring is stronger when new. Some of the tensioner have a hydraulic dampener that helps also.

[@mybigbackyard741]

What would be causing small screeching noise around that area when idling? It doesn't happen at first cold start, only after driving it around and can only hear from outside. It sounds like sheesh sheesshhh shessh sheeshhh then goes quiet then come back again after few minutes. Trying to describe it best I could lol. Happens with AC on or off. The noise appeared 2 weeks after replacing AC compressor clutch.

[@raymangtir]

I've just done mine but I removed the alternator. But a question the belt orientation, why is the belt say upside down, why isnt it in the grooves on the alternator and the AC pump? I have seen this many times and no one can give me the answer why. I've fitted all types of belts to all different kinds of applications but never seen them like this, apart from on these cars. Could you let me know why?

[@ThePracticalMechanic]

David Atkinson this belt has grooves on both side of the belt to give it increased grip to drive accessories on both sides of the belt. Not all of the accessories have grooves but still run on the grooved belt.

[@raymangtir]

@@ThePracticalMechanic ahh ok that makes sense. Thanks

[@henrikskovlundjuul7459]

what link could i buy the tool you use. thanks for a good video

[@ThePracticalMechanic]

This is a basic kit that fits several vehicles. I also have individual tools listed in the description. amzn.to/2MEgYkP

[@FL3345]

I have a 2010 tdi cup edition vw, I desperately need help solving an emissions code, any ideas on fixing emissions codes ? I replaced my egr valve thinking it would fix it but it didnt, not sure what is going on, my light is on but dont really feal any different going on with the car ... any ideas ?

[@phillmcaverty]

Fantastic video. Cheers

[@EdgewithHedge]

Can I use OAD in place of OAP type pulley? Engine is Fiat 1.9d

[@konstantin-big]

What of type pulley you use????

[@306-fromthestix]

I had a similiar problem with mine and it was pully overun.

[@richiepenaflor9844]

Hi, just want to ask where or which name of that tool your using and where to buy. Thanks for sharing this video..

[@johnstewart4749]

Were can u get it

[@weskarlson2287]

Very well done Sir!!!

[@EMonzon]

Awesome video, thank you.

[@Chris5044]

Great tutorial thank you! :)

[@azmisalleh6465]

Are you sure the belt installed correctly? It seem facing the wrong side.

[@ThePracticalMechanic]

This is a double sided belt on this car. There are many variations of the belt type and routing but many of these use a double sided belt.

[@OuttaHere7]

Excellent presentation!!? ***** Thank-you!

[@Nick110182]

Is that spline tool a torque rench ?

[@ThePracticalMechanic]

The two spines tools are not torque wrench’s or torx bits. The smaller tool is called a triple square bit and the larger tool is a alternator decoupler pulley socket. I hope that answers your question. If not, let me know.

[@metalartwelder]

You’re a great teacher! I found a small metal piece that looks as if it could be a partial edge or possibly a section of something that helped support the Alternator Decoupler Pully or keep it in place? I’m not a mechanic & am trying to problem solve & fix my own 2006 VW Jetta TDI. Any suggestions on how to tell if the alternator decoupler pully is bad? Hoping you see this question, but understand completely if not. Cheers for the easy to understand instructions!

[@E69apeTheMatrix420]

Very helpful! Thank you.

[@ThePracticalMechanic]

Your welcome!! Thanks for watching.

[@E69apeTheMatrix420]

@@ThePracticalMechanic With mine I can get away with removing the air filter assy for great access, then I can just use the 1 tool on the impact wrench. easy job.

[@E69apeTheMatrix420]

Hey sorry to ask such a trivial question, What if you dont have a locking pin and cant find a bolt that fits.. if I let the tensioner slack fully after removing belt is it bad for it? Kind regards.

[@ThePracticalMechanic]

Henry Phillips that not a problem. Locking the tensioner is more of a convenience.

[@E69apeTheMatrix420]

@@ThePracticalMechanic that's what I thought. It gets caught at the square part that blocks it going past vertical. Access not as good as I previously bragged about. Both tools needed 100%.

[@thompson114mt]

Great video. Did you have to remove anything to get clearance to reach the pulley and replace?

[@ThePracticalMechanic]

thompson114mt Thanks!! On this car I did not have to remove any other part to gain access. It would have been a little easier to see if I removed the large black pipe but that pipe can be a pain to remove so I normally just work around it.

[@litmois7672]

great video !

[@ThePracticalMechanic]

Glad you enjoyed it

[@litmois7672]

@@ThePracticalMechanic 😃😃

[@vampir335]

that tensionser shouldn't be bouncing like that

[@nigelmitchell351]

Mr PM, what is going on in this set up, I don't have a VW but surely the belt is not only inverted it's routed incorrectly ? Check out the idler, it should run on the flat side of the belt, here it doesn't. The belt should be turning the AC pump clockwise ! WTF ???

[@ThePracticalMechanic]

nigel mitchell it seems strange that VW routes the belt this way but it is the correct routing for this engine. The serpentine belt is double sided and has micro-v profiles on both surfaces. VW changed to a much longer belt and much more complicated belt routing a few yrs later and on those the compressor does rotate in a clockwise rotation. Good eye for spotting the odd German engineering. Here is a link to a belt routing image. images.app.goo.gl/HTZijoEwzt9id4PY9

[@nigelmitchell351]

@@ThePracticalMechanic My apologies PM, never heard of such a thing.! Thought it was only the French who were that accentric!.! I looked you up as I'm having bouncing tensioner problems with a Citroen C2 1.4 HDI. Changed the belt, tensioner and mass damper crank pulley, still it bounces.! So now only things left to change are alternator pulley, which is locked up, then AC pump, both of which spin quietly and smoothly. Extremely slight wobble to alternator pulley. Seems incredible to look at it that this could be causing the bounce, well you live and learn, as they say. I've had my head under bonnets for 45 years but....... Stay safe buddy. Mitch.

[@HalfassDIY]

Now that was slick !

[@MM-sq4cv]

Amazing, thank you!

[@khulisomuloiwa9620]

Good video. Is this belt grooved on both sides?

[@ThePracticalMechanic]

Yes there are two options on these engines depending on year. Some take a double sided belt and some take a single sided belt.

[@damiannowak8216]

Well done

[@coryboggs6247]

I have a 2000 jetta tdi where the alternator pulley broke off I'm not sure if I need the extra spline tool or does one of these kits or a couple of these kids have everything I need but just differ in price?

[@ThePracticalMechanic]

Some of the kit include more options than others. The basic kit should have everything needed for the VW amzn.to/2E5MbeS Let me know how it goes.

[@coryboggs6247]

@@ThePracticalMechanic I found the pulley on idparts and it has a kit for 29.95. well whatever some of the description parts that it has which I believe is only 3 pieces and has a 17 mm head for the box wrench and I don't see any 17 mm in the description of the basic kit

[@ThePracticalMechanic]

@@coryboggs6247 if this is the one you were looking at it should do the trick. www.idparts.com/metalnerd-serrated-alternator-pulley-bit-set-a4a5-p-564.html I looked at the description of the basic kit and it doesn't show the head size but it is the 33 splined socket.

[@coryboggs6247]

Yes that is the one I'm talking about I will be purchasing the basic kit them through Amazon and buying the alternator pulley off of idparts.I was just curious and worried why you had four different links I thought maybe I should also buy that splined socket

[@ThePracticalMechanic]

Cory Boggs No problem. Some people want the exact tool I’m using because they know it will fit and they normally have a slightly better fit, finish and warranty. I normally include both the tools I use and also a more cost effective option. I will make sure to clarify the description.

[@bohumilblazek565]

that is what is perfect tu say how to do that

[@iguana73]

the belt is installed inside out

[@ThePracticalMechanic]

It’s a double side belt

[@rajakaupunki4622]

altenator cluch is broken....

[@abdalqadr1]

Regards for you from Iraq

[@ArtyTheNewOne]

is that how the belt should be mounted asking for a friend...

[@ThePracticalMechanic]

Arturas Karelis yup. I know it looks strange but this is a double sided micro V belt. It has grooves on both sides even though some of the pillows are smooth.

[@mattsez2879]

im gonna find the guy that decided to put that pulley on my Jetta.......................

[@forgottenknowledge8917]

He said "shaft' 😄

[@lloydbarwick4977]

Great video, thanks

[@chriskahlson]

Well done video