330d F30 bottom end failure - bent conrods?

[TedStriker]

Hi,

Bought a 2013 F30 330d with 78k miles and full BMW history a few months back knowing it had a bit if a ticking noise under load which I expected (hoped!) to be an injector fault. To cut a VERY long story short, have found low compression on cylinders 2 and 3 so got the head off hoping for a head gasket failure between the two. Nothing found but now I see that cylinders 1,4,5,6 have around 1mm of piston protrusion above the block, as per spec, but cylinders 2 and 3 stop a mm or so short. Oh dear.

So I'm thinking bent conrods - probably due to hydrolock at some point? Could anything else cause low protrusion?

Questions - I need to find someone who can take the job of fixing this in the Leeds/Yorkshire area. I don't know if the engine has to come out (remember head is already off), or even if I should be expecting any further damage to be found such as pistons/cylinder walls/crankshaft? Can you get away with just replacing conrods?

In my 20 years of tinkering with cars it's the first time I've had bottom end failure so looking for advice/a shoulder to cry on!

Attached picture is of cylinders 3 and 4

Cheers!
Ted

[TedStriker]

Huskyman said:

Whe you turn the crank do the affected pistons travel up and down the bore the same ammount as the good pistons? Have you measured the difference between Top Dead Centre and Bottom Dead Centre? Do it for all six pistons if you can and let us know what you find.

Without having any precision measuring equipment, I can say the following...

The two 'bad' pistons appear to have the same travel as the good ones. The four good ones bottom out 89mm below the deck and the bad ones bottom out aproximately 90.5-91mm below. This would seem to be in line with the differences seen at the top of travel.

[TedStriker]

dhutch said:

Which I guess is what you would expect, a change in stroke would be very hard to achieve!

What's it like to get the sum off these things?

A lot harder than it would be if it wasn't an xDrive!

Necessary preliminary tasks:

Remove starter motor.
Drain engine oil.
Remove oil dipstick guide tube.
Remove front axle differential (AWD).
Removing bearing support (all-wheel drive).
Lower front axle support.

I'm not sure why BMW says you need to remove the engine to remove the pistons/rods though - surely it's a case of head off, sump off, undo bearing bolts and push through top of engine?

The manual also says 'Individual connecting rod replacement is not permitted; they are classified by weight class.'. Is this critical?

[TedStriker]

g3org3y said:

Really sorry to see that, especially on such low miles with a FBMWSH.

Was the only symptom a ticking? No rough running, loss of power or 'check engine' light?

Ticking which got louder under load, felt a bit down on power (but oddly not always).

BMW ISTA+ software flagged up smooth running correction codes on cylinders 2 and 3 and showed them both to be running weak on live test. No CEL or anything else.

As soon as I swapped injectors 1 and 2 over and the fault stayed with cylinder 2 I knew I was probably in for some bad news.

[TedStriker]

helix402 said:

When I used to rebuild BMW engines that had been flood damaged piston protrusion was the main accurate test for bent rods. I’d go for a second hand engine or a set of rods. Whatever goes in it’s probably worth putting a new timing chain and all bottom end bearings in.

Sadly second hand engines go for silly money, £2k or more and then there's fitting. Say I wanted to go cheap, but not so cheap that it won't last more than a few months, could I get away with a couple of rods, and big end bearings? How critical is it that I get a (new) matched set of all 6 rods?

Also, do you know if this could be done with engine still in the car?

Thanks

[TedStriker]

Charlie Croker mk2 said:

If you still haven't come up with a plan to fix it ? These guys in Rochdale are the real deal -- just for the record I do not have any affiliation with them .
https://www.facebook.com/Walkersofrochdale/?eid=AR...

Have just dropped them a message. Let's see what they say. Not a million miles from me if they turn out to be the place to go to.

[TedStriker]

Touring442 said:

The inevitable shagged 35d on their website. They really are crap.

By the time you've farted about lying on your back trying to repair the engine it situ, you could just haul it out. This is a bit of a chocolate engine and there will likely be more wrongness inside.

Yeah engine out is definitely not something I can do on my driveway so maybe the best idea. Lots of labour costs though?

[TedStriker]

dhutch said:

OP says engine our on drive is not practical, so far they have just pulled the head.

I don't know the labor cost for swapping an engine in a car like this?

I've been quoted £500 labour for an engine remove and refit, which seems almost too cheap to me. Going to speak to Walkers Of Rochdale today and see what they say.

[TedStriker]

Booked in at Walkers of Rochdale. They have given me option of replace conrods and check other bits for around £1200-£1300+vat or full rebuild with 6 month/6000 mile warranty for £1800-£2500+vat. Both options include engine removal and refitting.

I guess I decide on which way to go once it's stripped down.

Either way it's cheaper than getting a 'unknown' second hand engine fitted and they're perfectly happy to acccept a partially dismantled vehicle with a box of bits in the boot!

Will update as and when the job progresses.

Thanks for all the help so far

[TedStriker]

The verdict is in...

All 6 conrods bent, crankshaft journals scratched, rust in cylinder bores...

So it's a full rebuild. Not cheap at £2500+VAT but seems to be the going rate unless you go to the really suspect looking half priced rebuilds on ebay.

Sounds like it may be ready early next week though so the end is hopefully in sight.

Not my most successful punt!

Cheers,
Ted

[TedStriker]

So, I have the car back following 'Full Rebuild'. That included block hone, crankshaft polish, piston rings, main and big end bearings, 6 new conrods and a timing chain kit.

I just want to check with anyone knowledgeable here - could a rattle under light load and poor fuel consumption be caused by injectors not being coded correctly? Got a few issues but don't want to cast any aspersions on the quality of the work until I've checked the basics. I'm getting a noticeable rattle when pulling away from a standstill - my 4 pot Golf GTD sounds lovely in comparison! Definitely sounds engine/revs related and gets less under heavy load.

Is there anything else I should be resetting with ISTA+ after this much work?

Thanks,
Ted

[TedStriker]

helix402 said:

Injectors shouldn’t need coding if they’ve not been changed and put back in the same cylinder. No need to change anything post rebuild with ISTA, you could clear adaptions if you want.

The injectors were unlabelled in a box in the boot when they got the car - so unlikely they've gone back in the same places. I'll plug it in later today and see if they've recoded them.

[TedStriker]

clio007 said:

Why fart about with a rebuild. Is that the cost for a bottom end rebuild? Maybe there is an issue with the top end too?

You should have chucked the engine out as soon as you had the chance

And then done what?

[TedStriker]

A follow up to this...

Still getting noticeable rattle under light load (worse when warmed up). Checked injectors and they were not coded to correct cylinders. Have rectified this and it's made no difference. The noise does sound 'injectory' though - it's most prevalent between 1500 and 2500rpm and comes on if you lightly accelerate.

Also noticed while checking the injector values that 2 fault codes have been logged for the air mass system:

24CE00 - Measured air mass compared with calculated air mass too high
290900 - Air mass system: Measured air mass too high

Googling suggests a boost or intake piping leak.

Video below - rattle driving at 20mph and lightly applying throttle, then whine when I get next to a wall. This was with a fully warmed up engine. Ignore the spueak, that was just the handbrake.

https://www.youtube.com/watch?v=L-1nFDKph6A

Edited by TedStriker on Wednesday 25th November 13:30

[TedStriker]

Jaybmw said:

That's sounds like a prob donut to me.. can you feel it more so in the middle or to the rear or is it in the engine ?

Almost certain it's engine related - it changes based on engine speed not road speed, and happens to a lesser degree when stationary too.

[TedStriker]

wass006 said:

Any update on this? No update was ever posted I think I have a similar issue. And is rebuild a better option than buying a 2nd hand engine if I'm wanting to keep the car?

What sort of update are you looking for? I had the bottom end rebuilt.