Big End Gone

[Smallsy99]

So got the wonderful news that the knocking noise in my engine is caused by the copper/brass in my engine oil system. Essentially the engine has had it (3.0 N52)
Options are refurbished engine, second hand or engine rebuild/refurbishment.

Any experience on this at all - it’s probably the worse outcome it could possibly be

 

[Chippie]

Sorry to hear this, what’s the mileage on the engine?

 

[Joycey]

Depends on the zed as to what you do next, is she in pristine condition etc or is she ropey high mileage.

The cheapest option is to pull the engine and fit another, or if you're happy with the cost rebuild the current engine.

Your call.

 

[Smallsy99]

Sorry to hear this, what’s the mileage on the engine?

Currently sitting at 83,000

 

[B21]

Very unusual…I’d think a swap for a second hand one is on the balance of probabilities the best route..

 

[Smallsy99]

That’s what I thought, I had under the impression that it was the HVL but it’s not the case. Quotes I have range from £6k to £11.5k

 

[Ed Doe]

So got the wonderful news that the knocking noise in my engine is caused by the copper/brass in my engine oil system. Essentially the engine has had it (3.0 N52)
Options are refurbished engine, second hand or engine rebuild/refurbishment.

Any experience on this at all - it’s probably the worse outcome it could possibly be

got any videos at all? sounds very odd, if it actually is a big end failure, I think that's the second one I've ever heard of in over 10 years of faffing about on the forums with these cars, and the only other one was that Rory fella off autoalex, who bought a high mileage car which very much hadn't been looked after...!

 

[Joycey]

That's alot of money, seen a few second hand N52B30 engines around the 1K mark, I think "Mazcool" wo breaks Z4's has one at the moment.

Will take the best part of a day to remove and refit the replacement.

 

[Smallsy99]

So got the wonderful news that the knocking noise in my engine is caused by the copper/brass in my engine oil system. Essentially the engine has had it (3.0 N52)
Options are refurbished engine, second hand or engine rebuild/refurbishment.

Any experience on this at all - it’s probably the worse outcome it could possibly be

got any videos at all? sounds very odd, if it actually is a big end failure, I think that's the second one I've ever heard of in over 10 years of faffing about on the forums with these cars, and the only other one was that Rory fella off autoalex, who bought a high mileage car which very much hadn't been looked after...!

I have a video of it knocking yes, no idea how to add it to this forum though
There are basically copper/brass shavings in the oil filter. Which apparently can only come from the bottom end. The rebuild guy I just spoke too suggested that straight away when I told him the symptoms. Knocking sounds that increase from about 2.5/3k rpm

 

[buzyg]

6k seems a lot. Sad day, but if you can't find a considerably better quote, then I would probably be saying good buy to the car and starting the journey to find another.

 

[Chippie]

So got the wonderful news that the knocking noise in my engine is caused by the copper/brass in my engine oil system. Essentially the engine has had it (3.0 N52)
Options are refurbished engine, second hand or engine rebuild/refurbishment.

Any experience on this at all - it’s probably the worse outcome it could possibly be

got any videos at all? sounds very odd, if it actually is a big end failure, I think that's the second one I've ever heard of in over 10 years of faffing about on the forums with these cars, and the only other one was that Rory fella off autoalex, who bought a high mileage car which very much hadn't been looked after...!

I have a video of it knocking yes, no idea how to add it to this forum though
There are basically copper/brass shavings in the oil filter. Which apparently can only come from the bottom end. The rebuild guy I just spoke too suggested that straight away when I told him the symptoms. Knocking sounds that increase from about 2.5/3k rpm

You can’t upload a video on here unfortunately only photos, the easiest way is to upload to YouTube and then post a link on here.

 

[matsmith749]

Perhaps WBAC it & source another?

 

[B21]

£1,5k-£2k should get you a 3.0N52

 

[Smallsy99]

got any videos at all? sounds very odd, if it actually is a big end failure, I think that's the second one I've ever heard of in over 10 years of faffing about on the forums with these cars, and the only other one was that Rory fella off autoalex, who bought a high mileage car which very much hadn't been looked after...!

I have a video of it knocking yes, no idea how to add it to this forum though
There are basically copper/brass shavings in the oil filter. Which apparently can only come from the bottom end. The rebuild guy I just spoke too suggested that straight away when I told him the symptoms. Knocking sounds that increase from about 2.5/3k rpm

You can’t upload a video on here unfortunately only photos, the easiest way is to upload to YouTube and then post a link on here.

https://youtube.com/shorts/N4tT2pLG4z8?si=lA72fhKzsGvg5VKK

 

[Geddin]

I wonder if a second opinion could be worthwhile? Just to be sure of the options. It seems pricey to rebuild the big end.

It could be more beneficial to sell it for parts and buy a new one. There’s a few coming up under £9k

 

[Chippie]

I’m no mechanic and it’s hard to tell where it’s coming from, but to me it sound more rattling than knocking, I always thought big end was more of a regular knock varying with engine speed. (What does anyone else think)
I’d be inclined to take it somewhere else for another opinion, maybe worth while dropping the sump and examining the big end shells and crank.

 

[enuff_zed]

I’m no mechanic and it’s hard to tell where it’s coming from, but to me it sound more rattling than knocking, I always thought big end was more of a regular knock varying with engine speed. (What does anyone else think)
I’d be inclined to take it somewhere else for another opinion, maybe worth while dropping the sump and examining the big end shells and crank.

But regardless of where the noise seems to be coming from, it is the debris in the oil that is pointing to the bottom end apparently.
Is it worth spending a few quid on oil analysis first?

 

[Geddin]

I’m no mechanic and it’s hard to tell where it’s coming from, but to me it sound more rattling than knocking, I always thought big end was more of a regular knock varying with engine speed. (What does anyone else think)
I’d be inclined to take it somewhere else for another opinion, maybe worth while dropping the sump and examining the big end shells and crank.

100%

Over the years I’ve had a couple cars with the big end needing rebuilt. It’s definitely a more definite knocking that gets more severe the higher you rev. It is also a consistent knocking… the con rod is hitting off the cam shaft as it rotates, due to the gap caused by bearing failure. And i suspect he believes the copper is from the bearing failure… but it’s not the only place there’s copper.

It’s weird because at idle, there’s no knocking. I’m also no expert. But I’ve never heard an engine run smooth at idle if the big end is gone

 

[Usel]

This engine is smooth at idle:

https://youtu.be/hCzlJ8fMC44?si=o9oaTNHeandxEgOX

 

[Smallsy99]

It’s not bad at idle, there is a slight tapping but it’s quiet generally