Faint knocking? (Clip)

[Argenta]

Hello!

I need help on this!

My MC has done ca 4000km's since new rod bearings in June.
Over the past weeks I've gradually come to hear this faint knocking sound, only on tick-over, and only really inside car with fan etc turned off.
Now it's loud enough to be audioble in this little clip from yesterday:

https://youtu.be/kGOxUHfXA0k

Any thoughts?
It can't be my new bearings can it? Revving just makes it quiet.
It's also a bit fluctuating, it's not completely constant. Like somethings loose etc.

 

[MrPT]

When was the last major service?

Check it is actually coming from the engine and not the transmission or any of the ancillaries. If it is, personally I'd get it towed to a specialist and have the top end checked for valve clearance and/or cam follower or cam lobe wear issues. I know some people wouldn't be this cautious with only a slight tap, but you could rack up a much bigger repair bill by driving it.

 

[Beedub]

yeah i hear it.... good pickup for sure, us s54 owners seem pretty tuned into the various noises they make and also when something changes....

it sounds louder as you move to the rear of the motor, wouldn't drive it personally.

 

[Argenta]

Thanx.
Last major service was two weeks ago and valve adjustments was done 6000km's ago.

 

[mmm-five]

Thanx.
Last major service was two weeks ago and valve adjustments was done 6000km's ago.

What's a 'major service'...as the only service besides the I1 & I2 (both involving clearances) is an oil service, which is not what I'd call a major service.

These engine can be a bit 'rattly' but that sounds 'knocky'. I can't tell whether that's from the top or bottom of the engine. Probably need someone with a stethoscope (or long screwdriver) to identify exactly where.

 

[ph001]

Sounds just like my S54 tbh. Not sure I would be concerned about that - normal to my ears.

 

[Beedub]

their definitely a knocking that needs to be investigated, the ticks and metal tings are cool, this engine does sound complicated and kinda dead on idle but i think i can hear the knock OP is talking about, he's also noting its gotten louder to the point he's hearing it over the radio.

 

[MrPT]

Could be nothing, but why take any chances? Two of the most experienced Z4M owners in the country have just chimed in saying they'd get it looked at. Especially if you had the rod bearings done not long ago - that's warrantable work.

Mine made a knocking noise like that once (under the previous owner, albeit louder) and it ended up needing a top and bottom end rebuild. It was failure of nearly all of the cam followers - forum advice probably saved the camshafts themselves, avoiding an even more eye-watering repair bill.

 

[ph001]

Fair enough - may just be my crappy PC speakers here preventing me hearing anything unusual.

 

[Argenta]

Thanx again, yeah you prob need a set of earphones for this.
Will be back at the INDY tomorrow morning for a good check.

 

[Beedub]

Could be nothing, but why take any chances? Two of the most experienced Z4M owners in the country have just chimed in saying they'd get it looked at. Especially if you had the rod bearings done not long ago - that's warrantable work.

Mine made a knocking noise like that once (under the previous owner, albeit louder) and it ended up needing a top and bottom end rebuild. It was failure of nearly all of the cam followers - forum advice probably saved the camshafts themselves, avoiding an even more eye-watering repair bill.

dont suppose you got to keep any of the worn followers did you??? id love to see how they wear when they go bad... i can keep an eye out when the cam cover is off mine.

 

[AndyBeech]

Could be nothing, but why take any chances? Two of the most experienced Z4M owners in the country have just chimed in saying they'd get it looked at. Especially if you had the rod bearings done not long ago - that's warrantable work.

Mine made a knocking noise like that once (under the previous owner, albeit louder) and it ended up needing a top and bottom end rebuild. It was failure of nearly all of the cam followers - forum advice probably saved the camshafts themselves, avoiding an even more eye-watering repair bill.

dont suppose you got to keep any of the worn followers did you??? id love to see how they wear when they go bad... i can keep an eye out when the cam cover is off mine.

What was the mileage?
Can only imagine that could happen with a lack of oil, oil pump fail or something of the like? Certainly doesn't sound normal!

 

[firebobby]

Why did BMW build such a fickle engine, reminds me of the Triumph Stag in the early years. These engine issues and the sky high road tax just don't appeal to me on the M cars.

 

[BMWZ4MC]

Could be nothing, but why take any chances? Two of the most experienced Z4M owners in the country have just chimed in saying they'd get it looked at. Especially if you had the rod bearings done not long ago - that's warrantable work.

Mine made a knocking noise like that once (under the previous owner, albeit louder) and it ended up needing a top and bottom end rebuild. It was failure of nearly all of the cam followers - forum advice probably saved the camshafts themselves, avoiding an even more eye-watering repair bill.

dont suppose you got to keep any of the worn followers did you??? id love to see how they wear when they go bad... i can keep an eye out when the cam cover is off mine.

What was the mileage?
Can only imagine that could happen with a lack of oil, oil pump fail or something of the like? Certainly doesn't sound normal!

The followers wear due to inadequate case hardening as opposed to being a direct consequence of a lack of lubrication. If ignored, this leads to a consequential wear of the cam lobes. Schrick sell BMW followers with additional case hardening which (they claim) prevents the problem.
There has been much speculation that the problem affects only cars that have been thrashed from cold or tracked, or that it is a result of incompetently adjusted followers, but there's no evidence that any of this is true and the problem is surprisingly common amongst Z4Ms and E46 M3s.

 

[mmm-five]

Why did BMW build such a fickle engine, reminds me of the Triumph Stag in the early years. These engine issues and the sky high road tax just don't appeal to me on the M cars.

Is it really such a fickle engine? I don't know if the S54 failure rate is any higher than any other high output per litre engine?

Possibly don't hear much about 'cooking' engines as they're not rare/special enough to complain about.

BTW, mine has 130,000 on it - with nothing but regular servicing and the odd 'Italian tune-up'.

 

[AndyBeech]

dont suppose you got to keep any of the worn followers did you??? id love to see how they wear when they go bad... i can keep an eye out when the cam cover is off mine.

What was the mileage?
Can only imagine that could happen with a lack of oil, oil pump fail or something of the like? Certainly doesn't sound normal!

The followers wear due to inadequate case hardening as opposed to being a direct consequence of a lack of lubrication. If ignored, this leads to a consequential wear of the cam lobes. Shrick sell BMW followers with additional case hardening which (they claim) prevents the problem.
There has been much speculation that the problem affects only cars that have been thrashed from cold or tracked, or that it is a result of incompetently adjusted followers, but there's no evidence that any of this is true and the problem is surprisingly common amongst Z4Ms and E46 M3s.

But a failure of nearly all of them and the bottom end as well? If it was purely the case hardening then nearly everyone with an S54 would have to replace them at some point and that doesn't appear to be the case so...logically something else must be going on?
You say common but...I've spoken to a few independent specialists in the S54 world and from what I've been told I wouldn't say it's common, depending on you're definition of the term.
As the old saying goes, you only hear about the one's that have problems, not the many that don't.

 

[Beedub]

Why did BMW build such a fickle engine, reminds me of the Triumph Stag in the early years. These engine issues and the sky high road tax just don't appeal to me on the M cars.

please don't come in here talking shite. These are very robust motors, and have no less issues than the next performance engines.... We are talking decade old engines and most have seen the rev limit a good few times, as thats what ///M made it to do....

On the case of the solid top end, ferrari...used the same tech in the f12 TDF now a million quid car, and Porsche has just used it in the latest GT3........ its race derived stuff and things go wrong....

 

[firebobby]

Why did BMW build such a fickle engine, reminds me of the Triumph Stag in the early years. These engine issues and the sky high road tax just don't appeal to me on the M cars.

please don't come in here talking shite. These are very robust motors, and have no less issues than the next performance engines.... We are talking decade old engines and most have seen the rev limit a good few times, as thats what ///M made it to do....

On the case of the solid top end, ferrari...used the same tech in the f12 TDF now a million quid car, and Porsche has just used it in the latest GT3........ its race derived stuff and things go wrong....

Sorry mate but there are quite a few threads on here about bottom end/shell rebuilds and top end issues with these engines, just an observation really, Didn't think it was shite

 

[MrPT]

After some investigative work, I'm pretty sure mine was caused by skipped valve clearance adjustments during Insp II (not while under forum ownership but I know the indie quite well). That was at 44k and the failure was at 53k after hard driving (Nurburgring). The rod bearing shells were replaced during an exploratory look at the bottom end and didn't look great, but they didn't look much different to others with similar mileage and certainly hadn't spun or pitted badly. The general condition of the car is one of the best I have seen for its age and I'm hoping to hold onto it for a very long time.

Look away now if you are squeamish - here are some pics of the followers. I actually keep the worst one on my keyring as a reminder to take it easy!

I think there were nearly 100k S54s made, so I'm sure we're looking at a relatively low failure rate for such a highly strung engine. The problem is, I don't think your typical M3 or Z4M owner would understand just how much damage they could do by not religiously sticking to the servicing schedule and not ragging the engine from cold. It's so painful when you take someone out for a spin and you have to trundle around for ages warming the thing up. But it must be done!

Thanx again, yeah you prob need a set of earphones for this.
Will be back at the INDY tomorrow morning for a good check.

Good luck. Let us know how it goes, either way.

 

[Beedub]

After some investigative work, I'm pretty sure mine was caused by skipped valve clearance adjustments during Insp II (not while under forum ownership but I know the indie quite well). That was at 44k and the failure was at 53k after hard driving (Nurburgring). The rod bearing shells were replaced during an exploratory look at the bottom end and didn't look great, but they didn't look much different to others with similar mileage and certainly hadn't spun or pitted badly. The general condition of the car is one of the best I have seen for its age and I'm hoping to hold onto it for a very long time.

Look away now if you are squeamish - here are some pics of the followers. I actually keep the worst one on my keyring as a reminder to take it easy!

I think there were nearly 100k S54s made, so I'm sure we're looking at a relatively low failure rate for such a highly strung engine. The problem is, I don't think your typical M3 or Z4M owner would understand just how much damage they could do by not religiously sticking to the servicing schedule and not ragging the engine from cold. It's so painful when you take someone out for a spin and you have to trundle around for ages warming the thing up. But it must be done!

Thanx again, yeah you prob need a set of earphones for this.
Will be back at the INDY tomorrow morning for a good check.

Good luck. Let us know how it goes, either way.

jeeezzzzzzzz the flat spot on that follower is insane.... These are seriously tough material as well, the cam lobe must have been worn off! Also agree with your comments totally.