N47 Timing Chain failure --- how common is it still?

[bmwmike]

Deep Thought said:

Maybe they are maybe they're not. Irrespective, theres no evidence to suggest that timing chain failure on BMW diesels was / is down to stop / start. Battery life reduction and starters - yes, wholly with you there, but its a big leap from that to timing chain failure, no matter what your mate down the pub says.

Or some random on the Internet.

[iSore]

Deep Thought said:

given chains are stronger

Says who?

[Deep Thought]

bmwmike said:

Deep Thought said:

Maybe they are maybe they're not. Irrespective, theres no evidence to suggest that timing chain failure on BMW diesels was / is down to stop / start. Battery life reduction and starters - yes, wholly with you there, but its a big leap from that to timing chain failure, no matter what your mate down the pub says.

Or some random on the Internet.

Ah right, so some random on the internet is saying that its down to a design fault, exacerbated by infrequent oil changes and not keeping it topped up, backed up by various other input on here saying the same and on BabyBMW.net, various other threads on here, but you "think" it might actually be because that engine has stop / start and you're evidence to support this is your car needed a battery prematurely, backed up by your mate down the pub who agreed with you.

OK.....

Well, on that note, I'm out.

[Elliot2000]

Deep Thought said:

Ah right, so some random on the internet is saying that its down to a design fault, exacerbated by infrequent oil changes and not keeping it topped up, backed up by various other input on here saying the same and on BabyBMW.net, various other threads on here, but you "think" it might actually be because that engine has stop / start and you're evidence to support this is your car needed a battery prematurely, backed up by your mate down the pub who agreed with you.

OK.....

Well, on that note, I'm out.

The design issue is well noted, but continuous starting of the engine with the relative jolting of the engine and chains into life and the initial low oil pressure feed at both of the tensioners during startup is never going to help with already weakened chains

[bmwmike]

Deep Thought said:

Ah right, so some random on the internet is saying that its down to a design fault, exacerbated by infrequent oil changes and not keeping it topped up, backed up by various other input on here saying the same and on BabyBMW.net, various other threads on here, but you "think" it might actually be because that engine has stop / start and you're evidence to support this is your car needed a battery prematurely, backed up by your mate down the pub who agreed with you.

OK.....

Well, on that note, I'm out.

Think you're mixing me up with someone else, my car doesn't have stop-start and its on it's original battery.

Elliot2000 said:

The design issue is well noted, but continuous starting of the engine with the relative jolting of the engine and chains into life and the initial low oil pressure feed at both of the tensioners during startup is never going to help with already weakened chains

Bingo. That's all I'm saying. The new chains are like bog flush pulls. Not like chains of old. Unfortunately.

[DailyHack]

Yup, long oil service was the main bug bear of these engines, that is why alot of manufacturers including BMW have changed their policy on long life serving, albeit changed a little.

This together with stop/start, cannot be good for any engine over a number of years and miles.

Thats why my car gets oil every 8k and it's become routine when I get in my car, to turn stop/ste off, just as it's a routine to put my seatbelt on.

[bmwmike]

Wasn't it GTX magnatec advert that said 80% of engine wear occurs during engine startup? That was pre stop-start days so they were probably allowed to say it back then hehe

[Mr Tidy]

Elliot2000 said:

Deep Thought said:

Ah right, so some random on the internet is saying that its down to a design fault, exacerbated by infrequent oil changes and not keeping it topped up, backed up by various other input on here saying the same and on BabyBMW.net, various other threads on here, but you "think" it might actually be because that engine has stop / start and you're evidence to support this is your car needed a battery prematurely, backed up by your mate down the pub who agreed with you.

OK.....

Well, on that note, I'm out.

The design issue is well noted, but continuous starting of the engine with the relative jolting of the engine and chains into life and the initial low oil pressure feed at both of the tensioners during startup is never going to help with already weakened chains

Well put - you've found the right words for what I wanted to say!

[khtung]

Cavanagh-cccim said:

Timing chain just gone on my 520d It's the 2011 model with 150k on the clock. Was driving on the motorway at the time so very dangerous!

Car has a full service history and was only serviced a couple of thousand miles ago. If BMW advised the timing chain needed changing after X miles, I would have done it. I had never heard of the problem.

Now I am stuck with the dilemma of recovering it to BMW and paying them £120 for the privilege of them diagnosing it, then telling me they won't contribute to fixing it (as it's not all BMW Service history), or face a £3k+ bill to get it repaired independently.

It's really tarnished my view of BMW.

Sorry to hear that!
Mind to share is there any symptom and abnormal things or sound happening before the incident?

[Mr Tidy]

Deep Thought said:

And how is a BMW needing a new battery and subsequently a starter evidence that stop start causes the chain to elongate or break??

My sons 120d took its first battery at around 80K miles and never needed a starter. And yes, the battery had to be coded in.

Start / stop is known to be harder on batteries and starters. Start / stop is not known to cause chains to snap or elongate.

Edited by Deep Thought on Sunday 30th September 09:41

Edited by Deep Thought on Sunday 30th September 09:42

I never said it was evidence of stop/start cam-chain issues did I?

But stop/start wouldn't exactly help with battery and starter motor longevity would it?

My long gone stop/start 123d hasn't had an MOT since October 2018 at 103K miles, so it's probably been crashed, had a cam-chain failure or just been trashed!

Still I've moved on to straight 6 petrols.

[DailyHack]

(Anyone still interested in this....)

I came across a really good video on YouTube, N47 analysis.

Great watch if you have 20 mins of your life spare, bit of an eye opener and very well documented in my view.

https://www.youtube.com/watch?v=TAnGC8q1S4Q

[UkRob]

I believe BMW use single row chains same as Mercedes, being a single row they have always been vulnerable to failure certainly in Mercedes but are now failing far earlier in that make of car equipped with stop/start (as early as 45,000 miles). More stress is put on the chain at startup (overcoming the moment of inertia) and at slow speeds. Estimated lifetime stop/starts is 600,000, without stop/start 60,000. Simple way to deactivate stop/start, disconnect the small sensor attached to the negative clamp of the starter battery. Works on the two cars I own, a Merc and a Porsche Cayman, try it, if don`t like reconnect the plug, totally safe and the battery will last at least twice as long. My Merc is late 2011 CGI, never used stop/start, car has original battery.

[RUSSELLM]

That sounds like the Battery Monitoring Sensor. I’d do a bit of homework before disconnecting that, on every type of car. I’d be shocked if that voltage sensor only has stop/start relying on it’s signal.

The intelligent generators on the MHEV/PHEV cars, will almost certainly want to see a return.

[Touring442]

UkRob said:

I believe BMW use single row chains same as Mercedes, being a single row they have always been vulnerable to failure certainly in Mercedes but are now failing far earlier in that make of car equipped with stop/start (as early as 45,000 miles). More stress is put on the chain at startup (overcoming the moment of inertia) and at slow speeds. Estimated lifetime stop/starts is 600,000, without stop/start 60,000. Simple way to deactivate stop/start, disconnect the small sensor attached to the negative clamp of the starter battery. Works on the two cars I own, a Merc and a Porsche Cayman, try it, if don`t like reconnect the plug, totally safe and the battery will last at least twice as long. My Merc is late 2011 CGI, never used stop/start, car has original battery.

BMW have used single row (Simplex) timing chains since 1980. A few engines such as the M42, M44, S14 and various S88's used a Duplex. A good simplex chain will do 200'000 miles or more. That's a proper Jwis or Reynolds chain made to a proper specification from proper metal, not the marginal crap in the N47. They are noticeably lighter than older chains with predictable results. They're not uniformly capable of 200'000 miles and as such they're not fit for purpose. They've been redesigned for the B47 and are a lot better.

Merc chains failed because they were too heavy, same with the Triumph Stag. Too much weight = wear in the links.

You're spot on with the start/stop thing as well.

[JakeT]

The M50 and M52 chains were particularly stout, I'd feel short changed on 200,000 miles from one really. They do literally last the life of the engine, and often aren't the point of failure that kills them.

[hilly10]

I hate stop start,as soon as I start up I switch the stop start switch to off

[dasbimmerowner]

I ran a 2011 N47 powered car up until about 65k, at which point I swapped it. For all that time I made sure I had a BMW warranty on it. I also ran that car exclusively on V Power diesel for its cleaning properties to help keep the oil guides clean. I did notice on the very rare occasion I drove it hard there did sound to be more engine/chain noise. I didn't however turn stop start off on mine and that was used all the time on my fairly contested commute each day and servicing wise it was all done according to CBS.


I guess the only way I'll be able to tell anything is to check its MOTs as and when it gets them from a new lucky owner!

[DailyHack]

dasbimmerowner said:

I ran a 2011 N47 powered car up until about 65k, at which point I swapped it. For all that time I made sure I had a BMW warranty on it. I also ran that car exclusively on V Power diesel for its cleaning properties to help keep the oil guides clean. I did notice on the very rare occasion I drove it hard there did sound to be more engine/chain noise. I didn't however turn stop start off on mine and that was used all the time on my fairly contested commute each day and servicing wise it was all done according to CBS.


I guess the only way I'll be able to tell anything is to check its MOTs as and when it gets them from a new lucky owner!

Dont think you would of seen much issue in 65k miles in your use, 65k is nothing as has been mentioned already - regularly see N47 engines in 3 series and 5 series with way over 250,000 miles on, other bits changed out, but not the cam-chains, but plenty of oil changes mind

[Deep Thought]

DailyHack said:

dasbimmerowner said:

I ran a 2011 N47 powered car up until about 65k, at which point I swapped it. For all that time I made sure I had a BMW warranty on it. I also ran that car exclusively on V Power diesel for its cleaning properties to help keep the oil guides clean. I did notice on the very rare occasion I drove it hard there did sound to be more engine/chain noise. I didn't however turn stop start off on mine and that was used all the time on my fairly contested commute each day and servicing wise it was all done according to CBS.


I guess the only way I'll be able to tell anything is to check its MOTs as and when it gets them from a new lucky owner!

Dont think you would of seen much issue in 65k miles in your use, 65k is nothing as has been mentioned already - regularly see N47 engines in 3 series and 5 series with way over 250,000 miles on, other bits changed out, but not the cam-chains, but plenty of oil changes mind

Regular oil changes are KEY. Every 9,000 miles, and check the oil level weekly and top up as necessary.

[Mr Tidy]

Like I said earlier, I ran my 123d to 81K miles before I sold it, but it got an MOT in February this year just short of 109K so I imagine it hasn't had an issue even though it only ever got serviced to BMW intervals while I had it. Mainly because I had a BMW Service Pack!