Replace Timing Chain Tensioner (N20) pre 2015 cars

[Deepseaskateboard]

In the interest of some preventative maintenance, I was thinking about replacing the timing chain tensioner on my 2012 Z4 20i with the updated part, post 2015.

We have all read the horror stories regarding earlier n20 engines, and this is my reasoning:

. Cheaper to replace timing chain tensioner (TCT) than timing chain guides.

. Post 2015 cars had a revised design of tensioner, so the replacement would be an improved design.

. Accessibility to TCT is easy, no major disassembly required.

. As I understand if the TCT is too slack, this can cause increased wear and damage the guides, so why would it not be a good idea to change?

. Part costs about £50 - £60.


I have researched a little and found a discussion about this topic:

https://f30.bimmerpost.com/forums/showthread.php?t=1508793&page=3

Part number is: 11318685091 (for updated version… I think!)


So, my questions are:

Is this a good idea?

Are there any mechanical reasons why it’s not a good idea?

Would any other n20 owners be interested in having this done too?

Has anyone already had this done?

To me it seems a no brainer for the cost and effort involved, considering it can cause such catastrophic damage if the timing chain fails.

BMW updated the part, so the older version clearly isn’t up to par.

Apparently, reading that forum link, the n55 engine uses the same guides and chain, but a different tensioner, and that does not have the engine grenade issue.

I would like to draw on your advice and the wonderful knowledge base here.

Thanks all.

 

[TomZ4]

Checked with BMW dealership in UK before I bought my car and there was no recall for 2012 Z4 version. I understand that it was raised in USA as civil case but the chances of failing timing chain are something like 1-2% as far I could find online before I bought the car.

So I voted Bad Idea in your poll. I do however listen for slack chain noises every so often :?

 

[B21]

You many want to add at least one other variable…do it properly..

For completeness you may wish to add ‘and oil pump drive’

 

[Deepseaskateboard]

You many want to add at least one other variable…do it properly..

For completeness you may wish to add ‘and oil pump drive’

Interesting, is this a easy replacement?
Is this the chain which drives the pump?

I think it’s included in the timing chain guides kit if so.

The appeal of swapping the tensioner, is that it’s a very simple job, I am no mechanic by any means.
If replacing the oil pump drive is also straight forward, I suppose it wouldnt be a bad shout.

 

[B21]

There are two complete kits, the BMW timing chian kit which includes the new white chainguide assemblies and a new IWIS heavy duty cam chain and the oil pump drive kit again through BMW which is a complete unit of chain/drive/tensioner.

You can via Autodoc (and there may be other suppliers) order the Febi Bilstein equivalent which IS the BMW kits but with the BMW logo dremelled off!

You will also need the new crankshaft sprocket to match the new heavy duty chain.

A number of special tools are required so it put it pass my pay grade, others may be more capable.