[jabroni80]

Hi All

Haven't posted on here for a while but thought I'd let you all know of a serious problem I had with my 520d Msport.

My car slowly developed a ticking noise when up to temperature which I wasnt happy with- no error codes or performance issues just an irritating tick.
Anyway, took to my local dealer who gave me the dreaded news they thought it maybe timing related. They stripped the engine and found a slack chain and broken guide- not a cheap repair! Ive got the car back with new guide, top and bottom chains with tensioners.

I only purchased the car last May and was well aware of timing chain issues on the 520d but I was assured by Bmw my car wasnt affected as it was only a problem with older E60/61s. Its absolutely disgraceful these parts should fail when they are designed to last the life of the engine. Had I ignored the noise I would have been looking at total timing failure as the guide itself was broken.

I should point out my car is a 2011 model with 65k on the clock and full bmw main dealer service history.

Also, when I collected the car the rear suspension had sagged as it was parked in the dealers for a few days but thats for another post

[IanS100]

Did you get it fixed under an extended warranty or was it raid the piggy bank time?

[suj999]

I have a 2011 model too with 102k, I too thought there was a ticking noise and had my friend listen in too.

So bogged it in to the local dealer, after ousting £100 for them to check it they came back and said that's normal 'no faults found'.

[jabroni80]

I have driveline warranty cover so didnt hurt too much.

Suj999 I would just keep an eye on it.....you know the sound of your own car and when something dosent sound right. When I took mine to the dealers at first the thought I was just being fussy but after a 2nd opinion they decided to look further. I was petrified of the issues regarding timing chains on this engine and didnt want to consider what a new engine would cost had it failed.

[The Beast]

Well at least you spotted early

My made had his timing chain snap on his 1 Series, destroyed the engine!

[jabroni80]

Originally Posted by The Beast

Well at least you spotted early

My made had his timing chain snap on his 1 Series, destroyed the engine!

Yeah mate very very lucky. Just really annoys me I was assured by Bmw the problems didnt relate to f10/11 520d engines when I bought the car. Just hope I get some hassle free motoring now from the car.


......once I sort the air leak in the self levelling suspension

[Diesel Flash]

I likewise am annoyed reading your post, I sold my 2008 e90 for exactly the same reason, and updated to the f11 after being reassured these are not going to suffer the same timing chain issues, I guess all I can hope is that they have maybe rectified some of the initial issue and cases are fewer and far between.

best of luck with yours and the airsuspension issue, ill cross my fingers and toes.

[HighlandPete]

Originally Posted by Diesel Flash

I likewise am annoyed reading your post, I sold my 2008 e90 for exactly the same reason, and updated to the f11 after being reassured these are not going to suffer the same timing chain issues, I guess all I can hope is that they have maybe rectified some of the initial issue and cases are fewer and far between.

best of luck with yours and the airsuspension issue, ill cross my fingers and toes.

There doesn't seem to be conclusive data on why some engines (even out of the so called manufacturing date period) have the timing chain issues.

It appears the N47 engine has more timing chain issues than say the N57 with the same timing parts, but we assume more load, mass, inertia, etc., to its work cycle, does suggest some of the cause is in the way the N47 engine may be used. The fact there is some anecdotal evidence the N47S1 engine (325d) appears to have more timing chain issues, may suggest the higher tune, and/or working the engine more, revving more/higher could contribute to premature issues.

If that is the case, tuning the N47 and working it hard (low and high revs) is not going to help longevity. More regular oil changes may help a bit, but if it is due to stress and fatigue, possibly some working frequencies, (e.g. torque pulses at the rear of the engine where the timing chains are fitted), moderate use/engine load may be the best way to extend the life. Or replace the parts as a matter of course, ahead of issues.

HighlandPete

[jabroni80]

Originally Posted by Diesel Flash

I likewise am annoyed reading your post, I sold my 2008 e90 for exactly the same reason, and updated to the f11 after being reassured these are not going to suffer the same timing chain issues, I guess all I can hope is that they have maybe rectified some of the initial issue and cases are fewer and far between.

best of luck with yours and the airsuspension issue, ill cross my fingers and toes.

Thanks mate luckily the air leak should be far cheaper to repair.

To be honest although these timing chain issues shouldnt happen I may have been extremely unlucky as my car was registered 30 days before the final solution which appears to be safe so far. I maybe wrong but I think there has been 3 revisions since this problem first blighted the engine and I believe mines was fitted with the 2nd.

Bmw finally recalled e60/1 520d variants to fit a new tensioner and chain but this dosent apply to f10/f11 cars. I spoke to various independents near me and the were sick of the sight of this problem on e60s but did say it was rare to happen on f10s

I would agree with Pete and make sure oil servicing is regular.

[jabroni80]

Originally Posted by HighlandPete

There doesn't seem to be conclusive data on why some engines (even out of the so called manufacturing date period) have the timing chain issues.

It appears the N47 engine has more timing chain issues than say the N57 with the same timing parts, but we assume more load, mass, inertia, etc., to its work cycle, does suggest some of the cause is in the way the N47 engine may be used. The fact there is some anecdotal evidence the N47S1 engine (325d) appears to have more timing chain issues, may suggest the higher tune, and/or working the engine more, revving more/higher could contribute to premature issues.

If that is the case, tuning the N47 and working it hard (low and high revs) is not going to help longevity. More regular oil changes may help a bit, but if it is due to stress and fatigue, possibly some working frequencies, (e.g. torque pulses at the rear of the engine where the timing chains are fitted), moderate use/engine load may be the best way to extend the life. Or replace the parts as a matter of course, ahead of issues.

HighlandPete

Interesting points Pete. I'll deffinatly be driving mine lighter on the old right foot now thats for sure. A couple of the indys I spoke to advised annual oil changes and letting the engine heat up before reving higher. Mines has full bmw service history but I cant account for the way the first owner drove the car.....probably driven hard!

[IanS100]

HighlandPete: Do you think Auto Stop/Start is having any adverse affect on timing chains, ie are chains subjected to higher loads during start-up?
I hate Auto Stop/Start anyway and switch it off as soon as I think about it, but I wonder if the small fuel / emission saving is offset by the extra wear and tear on batteries and ancillary components?

[HighlandPete]

Originally Posted by IanS100

HighlandPete: Do you think Auto Stop/Start is having any adverse affect on timing chains, ie are chains subjected to higher loads during start-up?
I hate Auto Stop/Start anyway and switch it off as soon as I think about it, but I wonder if the small fuel / emission saving is offset by the extra wear and tear on batteries and ancillary components?

I'm not sure if stop-start has a direct connection with premature wear, as examples of failure seem as common in cars which cover high mileage, meaning longer trips. I'm of the opinion stop-start doesn't do any components any good, extra stress and wear rates must be higher, even if parts are beefed up a bit to accommodate the additional cycles.

I'm minded that a lot of the timing chain issue has to do with torque pulses and running high torque in the 4-pot engines. If the same parts were on the front of the engine the issues may not have materialised.

HighlandPete

[DDarkEnergy]

Originally Posted by HighlandPete

If the same parts were on the front of the engine the issues may not have materialised.

HighlandPete

Hi Pete, can you expand on this point please.
Why you think the orientation of the engine would affect the longevity of the timing chain components?
Cheers.

[HighlandPete]

Originally Posted by DDarkEnergy

Hi Pete, can you expand on this point please.
Why you think the orientation of the engine would affect the longevity of the timing chain components?
Cheers.

I'll come back to this later, but think in terms of high torque pulses, the timing gear taking on a shock absorbing role, coping with additional/different oscillations due to the close proximity to the flywheel.

[martin mustang]

Hi jabroni80, is your car produced before March 2011, according to my search on this before end of last year - see below, only cars produced before 1st March 2011 are impacted by this issue, curious to see if this is true.
My car was produced in May 2011, never the less still worried my one is also a possible candidate! Also how can you tell when diesel engines rattle any way with cold weather?
Both my car and my wife are equipped with the N47 (F10 and X3) so love to know how to tell something is up before too late.

The following models have the problem:

- E81/E82/E87/E88 116d/118d/120d - LCI cars built before 01/03/2011 only
- E90/E91/E92/E93 316d/318d/320d built between September 2007 and 01/03/2011 (anything with Efficient Dynamics could have the problem if it's built before 01/03/2011)
- E60/E61 LCI 520d built after September 2007 (models with Efficient Dynamcs, LCI 520ds built before September 2007 do not have this problem as they didn't change the engine until a few months after the LCI model was introduced)
- F10/F11 520d with a build date of before 01/03/2011
- E84 X1 18d/20d/23d with a build date of before 01/03/2011
- E83 X3 2.0d built after September 2007
- F25 X3 xDrive20d with a build date of before 01/03/2011

Models built between 05/01/2009 and 01/03/2011 do not require as many parts to be changed as those built before those dates.

There is no problem with N47 engines built after 01/03/2011 (for now).
More via this link: http://www.boards.ie/vbulletin/showt...php?p=82905489

[HighlandPete]

Originally Posted by HighlandPete

I'll come back to this later, but think in terms of high torque pulses, the timing gear taking on a shock absorbing role, coping with additional/different oscillations due to the close proximity to the flywheel.

To save time writing, take a look at the linked article, which contains some of the general points which could well apply to where you place the timing chains and how engineers design vibration control.

http://performancedevelopments.com/p...enginefailure/

We see from the article, changing engine components/designs can change the harmonic state, move the weak link (no pun intended) to different components.

With the BMW N47 engine, BMW moved the timing gear from the front of the engine where there is a vibration damper on the crank, to the rear, where the DMF (or TC) are not harmonic dampers. I'm sure the engine designers considered the implications, but clearly the timing gear became a weakness in the engine.

With the BMW N47 engine, when the first timing chain/guide issues emerged, BMW engineers did not solve the problem with the first fix. That indicates BMW didn't fully understand the mode of failure. Even with more modifications there still appears to be failures, albeit much rarer.

[IanS100]

Why was the timing chain moved to the back, are there substantial benefits, because it's turned a fairly simple chain swap into a hugely expensive epic of a job?

[xenon]

It's supposed to last the lifetime of the car and hence no issue with being at the back - or so the designers thought.

[HighlandPete]

Originally Posted by xenon

It's supposed to last the lifetime of the car and hence no issue with being at the back - or so the designers thought.

Hence the strong argument that BMW needed to sort the issues at their cost when failures occurred.

[HighlandPete]

Originally Posted by IanS100

Why was the timing chain moved to the back, are there substantial benefits, because it's turned a fairly simple chain swap into a hugely expensive epic of a job?

One reason put forward is the height of the engine. Taking the cam drive away from the top front of the engine, allows a lower 'top line'. This can be used to advantage, shared between body form and space 'under the hood' for better pedestrian safety.

Plus it moves weight further back, also slightly helps the centre of gravity.

[Pottsy]

Originally Posted by HighlandPete

More regular oil changes may help a bit,
HighlandPete

This.

Timing chains "stretch" and then if the tensioner is not up to the job (or the stretch is too great), then the chain will fail.

The thing is that they don't really stretch. They get longer, but this is due to the rotating bearings wearing in each link. To stop the bearings from wearing, you need the best oil, regularly changed.

Anything else that will prevent bearing wear is also good. I wonder whether those who have suffered early failure have bad habits - like starting the car and immediately revving it...

And of course, at the slightest whiff of an issue (so that'll be an odd noise), spend the money and get them changed.

[jabroni80]

Originally Posted by Pottsy

This.

Timing chains "stretch" and then if the tensioner is not up to the job (or the stretch is too great), then the chain will fail.

The thing is that they don't really stretch. They get longer, but this is due to the rotating bearings wearing in each link. To stop the bearings from wearing, you need the best oil, regularly changed.

Anything else that will prevent bearing wear is also good. I wonder whether those who have suffered early failure have bad habits - like starting the car and immediately revving it...

And of course, at the slightest whiff of an issue (so that'll be an odd noise), spend the money and get them changed.

Hi Pottsy,

My car has had 2 owners from new so I cant account for the first. What I will say, is the service record is exemplary (main dealer) and the car didnt have high mileage.
As for bad habbits, I always run my engine to allow oil to circulate and get up to temperature before leaving the drive and dont just switch off at the end of my journey.

The noise coming from my engine was only very slight and the dealer first thought I was being a little over senstitive to it. Its only when I persisted with getting it inspected by two indys as I still wasnt happy that bmw decided to look further. Bmw told me I would have to pay nearly 700 to have the engine looked at as they weren't convinced there was an issue. I decided to pay this as I wasnt enjoying driving the car fearing at any moment it could fail. It took the dealer 2 hours to find my suspensions were correct- chain rattle and broken guides. They told me had I not been so persistent with the issue there would have deftinatly led to total failure whether that be a snap or the chain jumping.