E60: Snapped Head-Bolts! No progress.

Well this has been the most fruitless weekend to date. First I discover the simple sump cannot be removed without lifting the engine and lowering the subframe. I am now the owner of a Clarke engine-crane, not cheap at £179.99, but it moved the job along. Next I find that to lower the subframe, almost everything must be unbolted from it - anti-roll bar, steering-rack etc. - and, once the mounts are unbolted, there is nothing stopping the engine from dropping straight onto you if something fails. I figured if I'm having the engine suspended freely above me while I work then it's best to get as much weight off it as possible, so began removing the head. The camshafts etc. came out in record time, but when I got to the head-bolts at about 12.30pm, the whole weekend's work ground to a halt.

Magnet to catch metal swarf from the drill.

Ok, it happens to us all from time to time, but I didn't expect snapped head-bolts as an added problem with the 530d rebuild. First my E14 torx-socket burst open, causing a trip to Halfords for two new ones, then 4 of the bolts snapped. Four! What a pointless setback. I did the correct removal sequence, so I must have over-tightened the head or they're just not ready to come back out after only 2 weeks, but as I got down to the last two head-bolts one of them snapped in the most awkward way imaginable - just the top of the head, leaving the giant collar and washer still incredibly tight against the head. All the other bolts did crack off slightly, the almighty creaking sound, but after that a further 3 of them stuck solid and the heads duly snapped off one by one, despite re-tightening the surrounding bolts. This hasn't half messed up the un-tightening sequence and has put the rebuild completely on hold.

Determined not to be drilled off, the head was finally
cracked off with a chisel and screwed out by hand.

I battled away until 3pm with the drill-bits I had available to me, before caving in and rushing to B&Q to buy a new 8 and 10mm titanium, again not cheap at nearly £17! I placed a large block-magnet in the head next to where I was drilling and held a smaller one to the other side in order to catch as much swarf as possible, but I will still have to give the cyl.-head and rockers a good blast in the parts-cleaner at work. The plan was to drill down the centre of the bolt head, boring it out gradually wider until the head broke away from the washer. Life is never so simple. The hole was slightly off-centre, so part of the shank was still attached even though I'd drilled well down it, so I began reaming the hole around the bolt head as much as possible. It was still stuck solid, so as a final shot in the dark I drilled a smaller hole in the rim of the bolt head and hit it with a chisel. To my amazement it cracked off and I was able to drift it round enough to become loose. I tried repeating the chisel process off the bat with the other 3 bolts, but they're having none of it, so I will have to bear out the drilling and reaming again. This is not going to be a quick thing, let alone getting that subframe down. Ah well, another week passes.

Problems to overcome:

• Drilling out stuck head-bolts.
• Getting the subframe down.
• Identifying the correct piston type.
• Clearing the head of any drilling debris.
• Identifying main source of oil leak.

E60: Oil Leak Verdict.

More bad news for the 5 Series I'm afraid. Got it up on the ramps at work with five mechanics and as many torches to finally see where the bulk of the oil is coming from. In this post [http://beemerlab.blogspot.co.uk/2014/07/e60-bad-oil-leak-was-it-running-too.html?m=0] my attention was solidly on the turbo oil-feed and return pipes, but further investigation has revealed that no oil is dripping from them and if they are leaking then it is only a seep, which is eventually building up on the underneath of the pipes. The main oil leak it would seem is running down the front of the engine. Unable to see where though or trace where the oil is running from due to the belts and pulleys covering the front of the block so well, I tentatively assumed it was coming from the front main crank-seal - oh dear. It stands to reason that swirl-flap damage could have unbalanced the crank somewhat and caused the front main-seal to leak, but this theory is stopped by two factors - 1. If oil was leaking so badly from the front crank-seal, it would be hitting the pulley and have the trademark 'spray pattern' in a circle around the main-pulley, and 2. If swirl-flap damage had unbalanced the crank enough to let this much oil out, then the engine would be a bit more recalcitrant that is being!

Pressurised oil?

So where is the oil coming from? We blasted the entire front of engine with brake-cleaner and stood back to watch where the oil arrived from. Thankfully we watched it pool and run down from above the main-pulley. The other lads suggested the usual suspects - rocker-cover gasket or a loose oil-way at the front of the block, but there is no denying signs of fresh oil are present everywhere on the engine where there is a gasket or seal. This means the oil is being forced out of these joints somehow by pressure building up in the crankcase and would explain how oil that cannot be from the frontal leak has made its way onto things that are nowhere near it, i.e the turbo feed/return pipes. It also explains my other big problem - oil entering the air-inlet. The worst case scenario is the main turbo-seal dumping oil right inside it. This makes for both a lot of oil getting blown into the engine, but also gives a smoke-machine effect out the back, the latter of which I have no signs of as yet.

Smoky CCV [Crankcase-Ventilator]?

I removed the rubber-hose that recirculates the CCV (crankcase-vent) back into the turbo while the engine was warm and running. Thick oily smoke was billowing out of the CCV, which I duly replaced [eBay £35], though it did not affect the problem and holding a hand in front of the smoking pipe for a minute leaves an oily residue. It would appear the oil is getting into the air-inlet by condensing down the CCV recirc pipe into the turbo impeller. This is definitely not normal CCV behaviour and finally gives a sure sign off abnormal crankcase pressure. Finally, with the car on ramps and the underbody-protection fully off it became clear that oil was dripping pretty bad from the back of the engine and pretty much everywhere else, even the sump.

Verdict:

I started another thread on BMW Land [http://www.bmwland.co.uk/forums/viewtopic.php?f=5&t=163497] and the torrent of 'I told you so' replies came in and backed up my fears about piston 6. The rings are stuck inside the piston and not making good compression. The lack of power isn't really being picked up under normal driving, but the blow-by is so bad that it's allowing combustion pressure straight into the crankcase, hence burnt oil and exhaust smoke pouring out of the CCV. You wouldn't think a swirl-flap bouncing round could cause the rings to do this, but check the picture below. Well, you live and learn. This weekend I will be stripping the sump off the car and then, of course, the head is coming back off, which means more new bolts and another new gasket, coming to about £120. Sadly, even BMW cannot tell me exactly which piston my engine has from neither my reg. or VIN, so I will have to pop it out the top of the block and identify it before ordering one as they're over £200, but this means the car is off the road at least another week. I managed 268.5 miles between engine rebuilds... 

Photo courtesy of http://bmwspecialistreading.co.uk/

E60: Complete Swirl-Flap-Damage Rebuild Cost.

Another head-gasket	£83.59	WEEK ENDING 10/8	£726.16
More head bolts	£39.55
New sump-gasket	£25.31
New rocker-cover gasket	£22.24
New CCV	£37.50	WEEK ENDING 3/8	£555.47
New Oil-filter	£5.99
Replacement cyl.-head	£225.00	WEEK ENDING 20/7	£511.98
New head-gasket	£85.55
New head-bolts	£37.48
Swirl-flap Blanks	£20.99
New thermostat	£33.99
5w30 Halfords Oil	£85.98
G48 Comma Coolant	£22.99

M57N Diagnostic Readout after Swirl-Flap Damage: [M57TUD30 6-cyl. Diesel]

E46: CCV + Intake Re-con.

Following on from this post - E46: Inlet full of oil! Re-con time. - where I discovered the intake-manifold was full of oil, I decided to give the entire thing a good clean out. The sensors, actuator and throttle-body were removed and given a good rinse with brake-cleaner. There was still oil pooling in the manifold, so I just kept on squirting brake-cleaner down the ports and turning the manifold round to run it all back to the main plenum. The Vanos [or Valvetec, whatever] seemed to benefit the most from this as the tubes were full of oil and sticking a bit. They now slide up and down freely and hopefully the electronic-actuator will still work now its clean.

The CCV sits below the inlet-manifold in a plastic-housing, along with the main wiring-loom box. Separately it looks like the diagram. These are known as 'vortex' type breathers, as crankcase pressure is relieved from the head via tube [3] and oil is separated in a spiral and runs down tube [4] back to the sump. The air-pressure is then vented via a diaphragm through tube [2] into the throttle-body, which provides a constant vacuum that keeps the engine as a suitable idle. When the vortex is clogged with oil and rust, pressure builds up in tube [3] and backs up into the head, down into the crankcase and forces oil and air back up tube [4]. This then pushes the diaphragm back and allows the oil up tube [2] into the inlet-manifold. This is clear in my case by the wiring-connectors to the other end of tube [2] and the diff.-pressure sensor being filled up with oil past the metal prongs.

Stripped, the CCV looks like this. The diaphragm housing was completely jammed solid with oily crud, which had leaked round the whole housing. The spiral oil-seperator was clogged with oily rust, which took a lot of getting out. All items were soaked in brake-cleaner and left in the parts-basin at work, then the oil-seperator was blown through with 200psi from the airline. Eventually I got quite a lot of air-flow through the vortex and the diaphragm-housing was squeaky clean, so I threw it back together and refitted the CCV and manifold. I've saved £45 on the part and this quick-fix should work for enough time at least for me to rule the CCV out if the problem persists. If it goes and comes back, £45 is not a lot to spend and I will be glad to do so if it cures the low idle problem!