OMG Big-end failure :-(

D

davegt

Active member
Northant's
I've had some tragic news on my Z, it went in to an indi yesterday to have the rocker cover gasket replaced along with a complete set of alu bolts after I found two snapped heads, whilst it was there I asked them to check on a very slight rattle I'd just started to hear around 2-3k revs when under load, they've diagnosed it as the big end bearings being on the way out :o . This came as a bit of a shock as the car drives perfectly, rather than "bodging" the shells I got a few quotes for a complete rebuild, these came back from £1800 - £6000 for a complete top to bottom strip and rebuild including honing the pistons, polishing the cams etc.

If it needs a rebuild then that's what it'll get but at 64k with full BMW history It wasn't what I was expecting. After looking at the rebuild cost vs a second hand engine for a couple of hours I decided to give the BMW customer help line a call, after a chat about the car they confirmed the service history I had is the same as their records so no issues there, they passed me on to my local dealer with a view to trying for a "goodwill" repair. I've agreed to have my car diagnosed at the dealer at my expense. The plan is to confirm the problem with the engine and then apply for a goodwill repair/contribution.

Maybe I should be going nuts that a low mileage BMW engine is showing these problems but that really isn't going to get me anywhere, I'm going to be as nice a pie (for as long as possible) and see what happens, the same dealer looks after my E91 and the wife's Cooper Clubman which may help, the Z had an inspection 2 just under 2.5k ago at the dealer in Oxford and the fault wasn't picked up then. I did say to the customer services person that I wasn't sure about applying for the goodwill due to the age of the vehicle but they seemed ok with the age due to the low miles and full dealer history, I'll be spending the next few weeks with more than just my fingers crossed.

Wish me luck :|
 
Be interesting to get another diagnosis in any event - wouldn't rely on just the one with such a large potential cost.

Hope things work out for the best.

Keep us informed. . .

:driving: :thumbsup:
 
Sounds like you're a bit fast in jumping to conclusions.
How did they diagnose that it's failed rod bearings?
2nd of all you have to find out why they failed (IF its the rod bearings). Otherwise you're rebuilding an engine that might fail again in weeks...

The N52 is known for ticking and ratteling :wink: but not for failed rod bearings..
 
All fair comments, I trust the indi that looked at the car, he's been looking after my BMW's for about 10 years, the second opinion will be via BMW, it's not cheap but in order to apply for "goodwill" BMW have to diagnose the fault, either way at least I'll have the correct information from the dealer before emptying my pockets further!
 
Gasket replacement & snapped head bolts at 60k :cry:
Interesting post & look forward to the update after BMW have given their verdict .
Did they give you indication of costs for their diagnosis /
 
From what I've been reading the rocker cover/valve cover alu stretch bolts are prone to breaking if they've been over torqued causing the gasket to leak, the leak was more of a weep but I wanted to get it sorted before it became an issue, I'm happy got the gasket sorted otherwise the bigger problem may not have been noticed, I've spoken to a few engine people and they've all said that they've had to rebuild N52 engine for various reasons. I bought it 4th hand and even though it has full history I have no idea if it's had the life thrashed out of it or if it's been allowed to get low on oil etc.

It'll be sorted eventually and then it'll have a nice set of coilovers fitted and depending on the repair cost maybe even a re-spray next year :driving:
 
if it were my car, i would change out the big end shells, check the crank for wear / dimension. see how that goes. the big end shells are the alarm of the engine.

I've doen this before when an engine has been run short of oil and the car has rattled the bottom end. you've got little to lose in my option and you will be back to where you started but you will be sure what is required. it a gamble, but not too costly.
 
If it goes to a good will gesture then they will be 100% sure of what they are diagnosing. I was very suspicious when they diagnosed my hydro unit and questioned it. Basically they have to be 100% sure otherwise they are seriously in the poop with BMW UK if its the wrong diagnosis.

Hope you get it sorted. :(
 
Wouldn't professional analysis of the oil pick up traces of big end failure?

As per others, a 2nd opinion is definitely required, & don't volunteer the diagnosis of the indi, let the BMW technicians draw their own conclusions.
 
Lack of oil would cause this (don't ask how I know :headbang: ). Wish you all the best with you claim but be prepared. You did book it in for the rocker cover replacing, was it leaking oil?
 
TonyP said:
Wouldn't professional analysis of the oil pick up traces of big end failure?

As per others, a 2nd opinion is definitely required, & don't volunteer the diagnosis of the indi, let the BMW technicians draw their own conclusions.
Click to expand...

At 64K miles there is every chance that contaminates already exist in the oil commensurate with that amount of use. the clever thing would be picking out what was normal for that age of engine and what was from the shells.

It could be the case that in its past it has been run low of oil and on a hard turn the oil was moved away from the oil pickup enough to merely rattle the bearings. Damage is now done if it is the Big end bearings. there really is only one sure way to find out. Sump off and drop the bearing bearing shells.

if the engine is performing well with no acceleration in the rattling noise, get a set of shells and and put them in. new oil and filter and away you go. If the crank is scored then you will be able to see this and plan for what to do next after you have buttoned it all up.

If you take it to BM and its rattled the bearing (through lack of oil) i have no doubt that they will not be sympathetic.
 
Will just have to wait and see what happens, they can investigate and decide what to do next. If it needs a rebuild that's what it'll get, maybe not at BMW but either way it be back on the road
 
How old is your car?

You might have recourse to the sale of goods act. If a failure happens outside of warranty but within what could be reasonably expected as a lifetime if properly maintained you can claim. That's why a lot of goodwill happens, they know that if it came to it they'd be liable.

I'm not suggesting you get nasty, they may well accommodate you, but if it looks like you might be facing a big bill, take proper legal advice.
 
56 reg so It's well out of warranty but as it only has 64k on the clock and full BMW history with the last service only 2.5k ago the dealer seemed happy to investigate the fault at my cost, which is the standard procedure, and depending on the outcome apply for goodwill, looking at various BMW related websites the "goodwill" set up it's very dealer dependant but even with the age of the car as it has low miles and full history it still has a chance of being considered.

Time will tell, It's going into BMW Northampton on Friday, the same dealer looks after my two other cars which may help and the service I've experience there has always been very good!
 
Good luck! Hopefully it will be supported. There's no way a BE bearing should have failed in this usage period if properly maintained.
 
Is it probable the head has been off before & if so i would want to know when , who by & why ?
Unless you have a blank cheque book i would want some cost idea before the dealer set,s about it with a spanner :cry:
 
I had big end failure in a Carlton few years back at high revs it was caused by a bodged gasket repair with hylomar dropping into the sump and clogging the oil pickup pipe,was lucky the crank was ok and changed the shell bearings myself.
 
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