Major N52 Issues... Ouch!

[coupedan]

So... looking like I'm in for an engine replacement / rebuild..

Car has always been serviced yearly and on time / early, early in life it had full main dealer, then TWG and now RBM.
Always used Shell V-Power and more recently Esso Synergy.
It's never been neglected - pretty much always said yes to any work that needed to be done in the past.

But, the story goes like this:
On my way to work, covered approximately 10 miles at this point so the engine was warm and hadn't been driven hard at all that morning.
Pull out of a roundabout gently to head onto a dual carriageway. Got to second gear at about 25mph, went to accelerate up to about 40mph.
Car hesitated and I got what sounded like top end knock (almost like a whole bunch of marbles in a can) type of sound.
Straighten up, into 3rd gear to get up to 50mph and a S**T tonne of blue smoke out the exhaust..
At this point I was less than 3 mins from work, so limped it slowly.

Come home time, started it up and a whole bunch of blue smoke that eventually cleared. Drove home fine, although admittedly I didn't give it the beans, so to speak.

So.. Valvestem oil seals right?
Wrong.

It now doesn't really smoke on startup - it will only do it after a longer journey.
Doesn't smoke on overrun.
Doesn't smoke if left idling for a while then revving it.

Smokes when giving it the beans (full throttle after around 3.5k RPM) at which point the cylinders get a misfire as they're full of oil.

Taken it to RBM who suspect piston rings, but can't tell me conclusively without stripping it down.
The car is at 152K miles - doing piston rings at that milage, you might as well do a full rebuild...

So, here is the question.. what do?

I need a car - I was happy to spend around £4.5K on a rebuild - however, I am struggling to find people to take it on and more so, take it on in the next coming weeks.
I'm currently without a car, which means I cannot currently go to work.

My plans are to buy a cheap runabout for now.. but the reasons I am here asking you wonderful people are:
1. Do I rebuild it?
2. Put a replacement 2nd hand engine in? (Although these appear to be rocking horse S**T)
3. Try and source a replacement new engine from BMW (Contacted them who say they are on a worldwide factory back order)
4. Find someone who can devote time and willingness to put a different engine in
5. Walk away from the car that I've owned for 10 years, take a huge loss in selling it as it's not worth buggar all and no one will want to buy a f**ked N52 engined Z4..

Any suggestions welcome..
As said I'm budgeting around £4.5k to get this fixed..

Cheers,
Dan

TLDR: Engine is f**ked - what do?

 

[brillomaster]

Hmm, well i would realistically ask yourself how much a car on 152,000 miles is worth with a working engine in the first place.

A car with a blown engine is still going to be worth a reasonable amount to someone, it wouldnt be completely worthless. put it on Ebay with an honest appraisal of the problem and someone will buy it off you who has the means to fix it up themselves, might get £3k for it.

personally, i wouldnt spend £4.5k rebuilding an engine that had already done 150k.

Also, how is the rest of the car? i'd be more inclined to keep the chassis if you'd just spent £2k on new suspension, for example, but if you're still on original parts, then might these have problems in the future?

i think, unless you're really attached to that car for some reason, ie it has a very rare spec/colour options/customisations etc. I would probably sell it as is, and buy another car with half the miles on.

 

[Zedebee]

Ouch indeed, that doesn’t sound like much fun. I can’t offer any practical advice except to say that you should be able to replace a 150k coupe for c.£7k (or 100k for <£9k) which makes spending £4.5k on a rebuild seem like a lot of money given that yours in good nick with a failing (not failed yet) engine must be worth a few grand as a project car. Plus the costs of buying a runaround in the the meantime and all the aggro are significant. Plus Coupes being broken for parts are rare as rocking horse poo too. A decent set of 224s with tyres and M-sport seats, if you have them, are worth almost two grand on their own.

Buy another one, keep all the bits you like and sell the old one as a project.

P.s. [ref]Brillomaster[/ref] beat me too it, but seems to share the same view

 

[coupedan]

I get that used car prices are silly at the moment, however the cheapest 3.0si coupe on AT is over £7k currently..

My thought process was that if I sell the car for £2k.. I've lost out on £4k on it's worth if it was working, so either way - I'm at a loss.

It had an inspection 2 in October plus over a grands worth of work, such as oil leaks and front-rear brake lines..
All chassis bits were replaced in 2018, which was Bilstein B12 pro, drop links, poly bushes all around, lower control arms etc.

The only things that were left to do this year were the rear top mounts were starting to perish and front discs and pads.

But then the engine went pop, so kinda out the window now though!

Thing is, an engine with 152k on is fully rebuilt.. as long as the crank, bores and cams were fine - everything else can be replaced and should be as good as new..

 

[Smartbear]

Is the ccv system 150k miles old?
Rob

 

[coupedan]

Is the ccv system 150k miles old?
Rob

CCV was replaced, probably 25K miles ago in 2018 / 2019.

 

[mr.tourette]

The obvious thing if you have the time/enery/will and space is to break it for parts yourself..you will certainly yield a more than 2k but its a big job in itself

 

[Ewazix]

Is the ccv system 150k miles old?
Rob

Picking up on Rob's point I'd want a firmer diagnosis of the problem before writing off the engine (or car), as it is piston rings are not the most obvious possibility unless one was broken and they sound bloody awful all the time when they let go. 150k on a well kept N52 is not even half worn.

Have you got the results of basic tests like compression and leak-down? Have they looked for fault codes? (Both are home DIY checks TBH). If those are OK than as Rob says the CCV, MAF or even a coil can all give similar symptoms. Let us know how it goes

 

[dhobbs]

Maybe put a different engine in it

There's a guy on instagram that puts the m5 v10 into 1m's. Not sure if that is expensive (engine alone) but would be a great car afterwards.


Dreaming aside, first thing really to do is get a proper diagnosis especially as it only exhibits itself advice 3.5k rpm

 

[Mr Tidy]

Really sorry to hear of your engine issues Dan, but I'm surprised Ross couldn't be a bit more specific.

Could he possibly do so if he had the car for a day or two, like Ewazix has suggested?

Picking up on Rob's point I'd want a firmer diagnosis of the problem before writing off the engine (or car), as it is piston rings are not the most obvious possibility unless one was broken and they sound bloody awful all the time when they let go. 150k on a well kept N52 is not even half worn.

Have you got the results of basic tests like compression and leak-down? Have they looked for fault codes? (Both are home DIY checks TBH). If those are OK than as Rob says the CCV, MAF or even a coil can all give similar symptoms. Let us know how it goes

Failing that could you see what Will at TWG thinks? But probably best not to tell either of them it has been to the other!

£4.5K seems a lot of money - I paid less than that for my E90 330i in 2019, complete with a sweet 107K mile 3 litre N52 engine!

I hope it's something simpler like CCV, MAF, etc.

 

[Silverstar]

A little while back a friend of mine's engine in his 2009 520d died, he was getting silly quotes to repair / rebuild it around 3 to 4K and some garages weren't even interested. Eventually he found a garage called Gemini Auto Works in Essex who were recommended by an engineering company that does machine work on engine heads / block and that chap rebuilt his engine which happened to be a broken timing chain for just £1200. I am not sure where in the country you are but they might be worth speaking to, my mate lives NW London and had his car towed up to Gemini so might be an option.