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

[Deep Thought]

DailyHack said:

Deep Thought said:

Out of curiosity, Cavanagh, what service interval were you getting it done at?

Interested in this as well, as it's been proven long intervals do exacerbate the issue...many manaufactuers (Mazda) to name one, relooked at their intervals and shortened them, as this hasnt only happened to BMW.

TBH, 150k is not alot of miles if the oil has been changed every 10k - it is if it's not been changed in 20k basically BMW service intervals...

I would find a good Indy and stay away from BMW garages, Peter Van deer in Huddersfield is a good shout and knows his bacon on these engines, but there are more around if this is not local.

+1

With my son's we got it serviced by BMW as per their service intervals (so it got the recalls and the FBMWSH stamps) but maintained and intermediate services done by a local indy. TBH although the car did (proverbially) keep me awake at night worrying about the chain (as it would have down to Bank of Dad to sort it out), i wish i'd bought it when he sold it.

[DailyHack]

Deep Thought said:

+1

With my son's we got it serviced by BMW as per their service intervals (so it got the recalls and the FBMWSH stamps) but maintained and intermediate services done by a local indy. TBH although the car did (proverbially) keep me awake at night worrying about the chain (as it would have down to Bank of Dad to sort it out), i wish i'd bought it when he sold it.

I have had two N47 engined cars (118d) which i took to 178k and now a 318d, just under 100k now, oil changed every 8k because im anal, and oil is cheap, I use any LL04 spec oil, despite many people only using branded marketing oil

I stopped worrying years ago, after worrying alot.

End of the day, £2k bill for a car isn't the end of the world in my eyes, think of all the money you saved on not doing cam belt services?

[Deep Thought]

DailyHack said:

Deep Thought said:

+1

With my son's we got it serviced by BMW as per their service intervals (so it got the recalls and the FBMWSH stamps) but maintained and intermediate services done by a local indy. TBH although the car did (proverbially) keep me awake at night worrying about the chain (as it would have down to Bank of Dad to sort it out), i wish i'd bought it when he sold it.

I have had two N47 engined cars (118d) which i took to 178k and now a 318d, just under 100k now, oil changed every 8k because im anal, and oil is cheap, I use any LL04 spec oil, despite many people only using branded marketing oil

I stopped worrying years ago, after worrying alot.

End of the day, £2k bill for a car isn't the end of the world in my eyes, think of all the money you saved on not doing cam belt services?

Yeah thats probably the reality of it in hindsight. He bought it when he was 19 with 45K miles on it @ 3 years old and we ran it to near 80,000 with no issues other than consumables. I should have bought it off him last year when he sold it and used it as my airport runner.

[QuiteQuietCerb]

Have had 3 120d s all remapped no issues at all

[Deep Thought]

QuiteQuietCerb said:

Have had 3 120d s all remapped no issues at all

Not seeing the link?

[DailyHack]

Got lift back in a 318d 2010 E91 N47 taxi the other day from a night out..was interested in this, particulary because of all the talk of cam chains etc

This car had 246,000 miles on the clock, and it "ran beautifully" - quoting the driver, didn't even have a rattle anywhere!

Only issues he has had with it (he's had it from new) were shocks and dampers around 180,000 and it's had a clutch at 150k. It Gets fresh oil and filter every 10k the cheapest LL04 spec he said, usually Asda when he pops in for his groceries! Ha!

Says alot I thought...so thought I would share this with you guys

[Deep Thought]

DailyHack said:

Got lift back in a 318d 2010 E91 N47 taxi the other day from a night out..was interested in this, particulary because of all the talk of cam chains etc

This car had 246,000 miles on the clock, and it "ran beautifully" - quoting the driver, didn't even have a rattle anywhere!

Only issues he has had with it (he's had it from new) were shocks and dampers around 180,000 and it's had a clutch at 150k. It Gets fresh oil and filter every 10k the cheapest LL04 spec he said, usually Asda when he pops in for his groceries! Ha!

Says alot I thought...so thought I would share this with you guys

Interesting.

Backs up the general consensus that they need serviced every 8-10K miles.

[bmwmike]

Or that stop start kills the chain,a taxi engine is likely to run for hours and hours non stop

[Deep Thought]

bmwmike said:

Or that stop start kills the chain,a taxi engine is likely to run for hours and hours non stop

Any evidence to support that? General consensus from owner and on specialist forums is long oil changes and oil level being unchecked and dropping below min...

[bearman68]

DailyHack said:

Had 2 N47 since 2008, one "vintage" 118d, took this to 179k (no issues). Now got a 2012 318d, yup with the N47 engine, just dumped 30k on this, now its nearing 90,000 miles.

The secret is to forget changing oil at 20-25k intervals, this I am afraid is insane, I do not care what anyone says, I drop my oil every 8-9k, and many mechanics say the same!

No cam-chain car should go this far on dirty oil, especially a diesel, they are dam hard on their oil.

BMW wont give a sh*t whether the engine lasts to 100k+ they bow down to the lease/business market, and 25k oil changes looks cheap on paper to running a fleet of business cars.

Many marques now have reduced their service schedules now, because of this issue. Mazda is one, as believe it or not they had massive cam-chain issues because of long intervals.

There was a problem early on, 2007/08 but find me a "snapped" chain since 2011? Noisy yes, but not "snapped".

Edited by DailyHack on Wednesday 28th March 13:03

I've changed a snapped one - not noisy at all, but defo snapped, on a late 2011, with 97k miles and full BMW service history. So yes, pink elephants do exist.

[DailyHack]

bearman68 said:

97k miles and full BMW service history.

I would hazard a guess a full BMW service history is probably why it snapped??

As it would of had oil intervals every @15/20k which is no good for any car, especially a chain driven one.

[bmwmike]

Deep Thought said:

bmwmike said:

Or that stop start kills the chain,a taxi engine is likely to run for hours and hours non stop

Any evidence to support that? General consensus from owner and on specialist forums is long oil changes and oil level being unchecked and dropping below min...

Just common sense

[Mr Tidy]

Deep Thought said:

bmwmike said:

Or that stop start kills the chain,a taxi engine is likely to run for hours and hours non stop

Any evidence to support that? General consensus from owner and on specialist forums is long oil changes and oil level being unchecked and dropping below min...

Well I bought a pre-reg 123d in 2008 with the stop/start nonsense and it needed a new battery after just under 55K miles. And with it being full of "AGM" wonderfulness it needed coding to the car, so it cost over £250 by the time it was fitted!

But then just before 77K it needed a new starter motor, which only cost £600 from BMW!

I can't help thinking these issues may have been related to starting/stopping, but by then I became aware of N47 diesel cam-chain issues so I sold it before it broke in a big way because at that time BMW hadn't begun the "Quality Enhancement" programme.

So I sold it as soon as I could on 81K miles before it became scrap!

Only straight 6 N/A petrol for me since then.

[Deep Thought]

Mr Tidy said:

Deep Thought said:

bmwmike said:

Or that stop start kills the chain,a taxi engine is likely to run for hours and hours non stop

Any evidence to support that? General consensus from owner and on specialist forums is long oil changes and oil level being unchecked and dropping below min...

Well I bought a pre-reg 123d in 2008 with the stop/start nonsense and it needed a new battery after just under 55K miles. And with it being full of "AGM" wonderfulness it needed coding to the car, so it cost over £250 by the time it was fitted!

But then just before 77K it needed a new starter motor, which only cost £600 from BMW!

I can't help thinking these issues may have been related to starting/stopping, but by then I became aware of N47 diesel cam-chain issues so I sold it before it broke in a big way because at that time BMW hadn't begun the "Quality Enhancement" programme.

So I sold it as soon as I could on 81K miles before it became scrap!

Only straight 6 N/A petrol for me since then.

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

[Deep Thought]

bmwmike said:

Deep Thought said:

bmwmike said:

Or that stop start kills the chain,a taxi engine is likely to run for hours and hours non stop

Any evidence to support that? General consensus from owner and on specialist forums is long oil changes and oil level being unchecked and dropping below min...

Just common sense

Sorry but no its not "common sense".

Starting a car does not put excessive stress on a timing chain / timing belt. If it did, then timing belts wouldnt be prevalent as they would snap.

However infrequent oil changes / allowing the car to run low on oil, does exacerbate the design flaw in that engine.

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

[bmwmike]

Deep Thought said:

Sorry but no its not "common sense".

Starting a car does not put excessive stress on a timing chain / timing belt. If it did, then timing belts wouldnt be prevalent as they would snap.

However infrequent oil changes / allowing the car to run low on oil, does exacerbate the design flaw in that engine.

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

No doubt oil changes help but think of the inertia and stress each time an engine starts and stops.

Starting up the crank pulls on the chain to get the timing gear moving.

When engine stops, the crank stops and the intertia of the timing gear is taken up by the chain.

Chatting to a mechanic mate in the pub last night about this. Seems obvious that most of the chain strain is caused during stopping and starting. There are pulses during running, obviously, as well.

Edit to add not sure why you mention cam belts?. And yes, very obviously, running too low on oil will cause damage. Agree on that point.

I just don't think it's one single cause. Arguably the root cause is crappy design by a company that have made as many crappy engines as they have belters which are exacerbated by various things like extended service intervals, thinner chains for less drag and interia losses, stop/start etc. Ironic considering their middle name is engine.

Edited by bmwmike on Sunday 30th September 11:33

[Deep Thought]

bmwmike said:

Edit to add not sure why you mention cam belts?. And yes, very obviously, running too low on oil will cause damage. Agree on that point.

I just don't think it's one single cause. Arguably the root cause is crappy design by a company that have made as many crappy engines as they have belters which are exacerbated by various things like extended service intervals, thinner chains for less drag and interia losses, stop/start etc. Ironic considering their middle name is engine.

I mentioned cam belts because if it was caused by intertia, we'd see an awful lot more cam belt failures generally (given chains are stronger) and loads of cars with timing belts have stop start.

The root cause IS a crappy design, and the way to mitigate a lot of the risk of failure is by ensuring you do more regular oil changes and check and top up the oil when necessary. The engine does use oil and far too many people simply dont lift the bonnet between these 18,000 mile services and end up running below the minimum.

So whats KEY in longevity is more regular oil changes and keep it topped up. Using or not using stop start will make a zero difference and i wouldnt be reliant on that as a way of preventing timing chain problems on these engines.

Edited by Deep Thought on Sunday 30th September 14:13

[bmwmike]

Deep Thought said:

bmwmike said:

Edit to add not sure why you mention cam belts?. And yes, very obviously, running too low on oil will cause damage. Agree on that point.

I just don't think it's one single cause. Arguably the root cause is crappy design by a company that have made as many crappy engines as they have belters which are exacerbated by various things like extended service intervals, thinner chains for less drag and interia losses, stop/start etc. Ironic considering their middle name is engine.

I mentioned cam belts because if it was caused by intertia, we'd see an awful lot more cam belt failures generally (given chains are stronger) and loads of cars with timing belts have stop start.

I'm not so sure that modern chains ARE stronger. Do you have any info on that? Chains are much less meaty these days than they used to be. Single vs duplex etc. Belts on the other hand are very strong.

[Deep Thought]

bmwmike said:

Deep Thought said:

bmwmike said:

Edit to add not sure why you mention cam belts?. And yes, very obviously, running too low on oil will cause damage. Agree on that point.

I just don't think it's one single cause. Arguably the root cause is crappy design by a company that have made as many crappy engines as they have belters which are exacerbated by various things like extended service intervals, thinner chains for less drag and interia losses, stop/start etc. Ironic considering their middle name is engine.

I mentioned cam belts because if it was caused by intertia, we'd see an awful lot more cam belt failures generally (given chains are stronger) and loads of cars with timing belts have stop start.

I'm not so sure that modern chains ARE stronger. Do you have any info on that? Chains are much less meaty these days than they used to be. Single vs duplex etc. Belts on the other hand are very strong.

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.

[The Mad Monk]

greenarrow said:

OK,I have been spending more time looking up potential purchases suitable for my new work commute, which is a twice weekly drive from my home nr Bournemouth to Dorking, 95 miles away, a pretty awful drive tbh, so I want something comfortable and torquey and with reasonable MPG. My weekly mileage is current just over 400, with weekend trips added in....

Anyway, the 520d (or 320d) seems to fit the bill well, big (for the family), comfortable and decent MPG....in many ways, I think it would do the job well.

But every google link refers to the dreaded N47 timing chain problem. I am just wondering how much of an issue this is still. BMW obviously shifted thousands of cars, the majority of which I am guessing have been fine, but it is still a worry...anyone got any information on this?

Wiki says yes

https://en.wikipedia.org/wiki/BMW_N47