idler pulley

[Dickymint]

Ok so brought a new aux belt and looking into it they upgraded the tensioner from mechanical to hydraulic so me being me cant just do the normal and replace what's there I have brought all new parts to do the upgrade..... that I'm happy with but what I cant figure out is my mechanical system does not use the idler pulley so when I change them over do I fit the new idler pulley? I guess its supposed to go on there but cant find someone on the net that's done the change that says its a extra you need to buy. (I have brought it anyway)

anyway before I do that there is a snapped bolt for the thermostat I need to remove, wish me luck (its rusted away )

 

[Lee]

Enjoy mate, I've had a few of them bolts snap. Seems to be common. Buy a set of easy outs.

 

[Sean d]

Ok so brought a new aux belt and looking into it they upgraded the tensioner from mechanical to hydraulic so me being me cant just do the normal and replace what's there I have brought all new parts to do the upgrade..... that I'm happy with but what I cant figure out is my mechanical system does not use the idler pulley so when I change them over do I fit the new idler pulley? I guess its supposed to go on there but cant find someone on the net that's done the change that says its a extra you need to buy. (I have brought it anyway)

anyway before I do that there is a snapped bolt for the thermostat I need to remove, wish me luck (its rusted away )

Whats the advantage of the upgrade if you don't mind me asking.

 

[Dickymint]

looks nicer , been doing some research and the stock one can bounce against the belt and BMW replace them in a service and that's about it, price is almost the same for either.

 

[Dickymint]

bolt is out and everything fitted (thermostat and water pump ect) except the idler pulley, still need to know if I need it or not

 

[t-tony]

I changed the pulley with my tensioner on my Z3 2.0. It was the pulley bearings that were knackered and had become very noisy. It's a no-brainer really as it is most likely a bearing failure which would throw the belt off. This was the old one.

View: https://www.youtube.com/watch?v=R3B1bWF0Lic&index=26&list=FLC-M7yLKSNJlaaiUga62JhQ


Then after fitting the new pulley. At 15 seconds you can hear how quiet it is after the Aux. air pump stops running.

View: https://www.youtube.com/watch?v=WUojMoDNgUQ&list=FLC-M7yLKSNJlaaiUga62JhQ&index=25


Tony.

 

[Dickymint]

Cheers but changing it is not a problem and I have brought one anyway, its not if I should change it its should I have one?

I'll try to be more clear

1, I had the old mechanical tensioner and NO idler pulley
2, I have changed to hydraulic tensioner
3, I have seen some pics of engines with a idler pulley so brought one just in case
4, realoem.com is no help as the pic shows the mechanical pulley but also a idler pulley, if its a old pic used with new part numbers then why the pulley?
5, if no one knows then I'll just have to try it and let people know what works, I have ordered a longer bolt anyway just in case

http://www.realoem.com/bmw/enUS/showparts?id=CN12-EUR-05-2002-Z3-BMW-Z3_22i&diagId=11_6226

 

[Dickymint]

OK so just to clear this up when you change to hydraulic tensioner you can put in the idler pulley or not, I have tried both and either works fine, I have decided to leave it off for 2 reasons, one is its less to go wrong and second it was easier to put the belt on with out it, the tension is the same either way
don't know why some cars have it and some not......

 

[t-tony]

So long as you have enough tension on the belt and it rotates the right way all should be good.

Tony.

 

[Dickymint]

just one extra point If you decide to change it for the hydraulic tensioner make sure you run a 8mm tap in the holes as they are not used and are full of crap and oxidisation ect,
the one I brought came with tensioner and pulley wheel and all the bolts for £33 , l was reading on the internet a possible reason it was changed by BMW, there was a few people that had the casing brake that holds the mechanical tensioner when the pulley wheels fails....... not that I believe everything I read on the net but it kinda makes sense "the upgrade" having better fixings and not being spring loaded