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Showing posts with label autopsy. Show all posts
Showing posts with label autopsy. Show all posts
Friday, 8 August 2014
Saturday, 12 July 2014
E60: Engine Autopsy Verdict.
Well, contrary to my earlier verdict of no damage to the head, a bit of informed explanation reveals the corroded surfaces in cyl. 6 are in fact battered metal from the where bits of my swirl flap were bouncing around inside it. Not good!
After having my photos pored over by the engine diagnosis experts on BMW Land, the best version of events of that fateful Tuesday are below:
1. Swirl flap no. 4 breaks up and bits enter cyl. 4.
2. Inlet valves jamming open on cyl. 4 cause a backfire and blasts the loose remains of the swirl flap into the intake plenum.
3. The turbo forces the swirl flap remains along the plenum, with bits ending up in cyl. 5 and the majority entering cyl. 6.
4. Cylinders 4 and 5 continue to fire with slight lack of compression.
5. Trapped debris in cyl. 6 begins to ricochet around, causing damage to the alloy piston-crown and the top of the combustion-chamber in the head until the inlet valves cannot close fully and compression is lost entirely.
Worst bits:
- Cylinder-head is finished. Valve-ports on cyl. 4, 5 and 6 need regrinding and fitting with some new valves. The top of the combustion chamber in cyl. 6 needs completely regrinding into shape.
Best bit:
- The engine still turns freely, cyl. 4 and 5 are virtually damage free and do not need replacing.
- Piston 6 compresses in the block still, so no damage to piston-rings.
- There is no damage or scoring to the cylinder walls.
THE REPAIR [in theory...]
- Repairing the head will cost ~£350, the cheapest Birkenhead-Engines can do and may still need further work, so a replacement is needed. Birkenhead-Engines say they have one such in stock, removed from another E60 530d, though what year they are unsure. It is not re-con and they say I can take my chances for a mere £200, but at least they know the valves etc. all work so it looks like this is the way to go.
- As long as I remove any tiny debris from cyls. 4 and 5, I am happy that they are working 99% as well as they should and do not need any repair.
- Cyl. 6 is battered and, although it is compressing in the block, the jagged metal crown will mess up proper combustion even if it fires ok. Worse, bits of the jagged alloy will probably break off during combustion and ping around the cylinder some more, potentially messing up the valves again so really the piston needs replacing.
- Not only is finding a single replacement piston very difficult, the job to replace it requires removal of the sump and big-end shell. This, with all the under-trays and cross-members is a colossal task in itself and, with the car parked on loose gravel, it's looking like a no-go.
- The short-cut solution to piston-6 looks like it's going to be a jenky regrind with the piston still in the engine. I will turn the crank by hand so that piston-6 is in its topmost position and get in there with a die-grinder, removing all the proud bits of metal and re-shaping the 'swirl-pot' and piston-crown as well can be. This ultimate bodge could be the end of a relatively unscathed engine. It could also be the only way to get the E60 back on the road quickly and with a minimum of fuss... Fingers crossed.
COST:
- Replacement cylinder-head: £225. [Birkenhead Engines]
- New head-gasket: £85.55. [Euro Car Parts]
- New head-bolts: £37.48. [eBay: dusty789blue]
- Swirl-Flap Blanking Plates: £20.99. [eBay: myldanautodesignltd]
- New thermostat: £33.99. [I broke the housing - Ebay: carpartssaver]
- Oil: £85.98. [Halfords, own-brand BMW Fully Syn. 5w30]
- Coolant: £22.99. [Halfords, Comma G48]
TOTAL: £511.98.
Sunday, 6 July 2014
E60: 530d Engine-Death Post-Mortem:
Had the rough-running / misfire from the vid in this thread [], so I've quickly whipped the cyl-head off [lol!] and this is what I found...No. 4 swirl-flap has broken off and is missing from inlet-manifold. Some technician could have removed or broken this with the mani. off in the past, but this is unlikely so it looks to have been chewed by the engine. With all that intake-pressure it's possible the skinny flap has been totally disintegrated by the valves / piston and blown through the exhaust in tiny pieces...
Image resized to 50% of its originalize [1600 x 1200]
...because there is no sign of it in the head, or inside cyl. 4 / the exhaust manifold. The turbo is spinning great and there is no play in the spindle. You would imagine the flap getting stud behind the inlet-valves, right down the inlet-port, but there is just no sign of it. I got the inlet valves down using a home-made valve-spring compressor, built from a piece of angle-iron and an M10 nut/bolt and sent pipe cleaners through. There is no obstruction in the head at all. Ima
resized to 37% of its original size [1200 x 1600]
Slight marking on piston 4 suggest the flap has been mashed through the cylinder, or that the inlet-valves have gingerly contacted the piston while that was going on.
Image resized to 37% of its original size [1200 x 1600]
In the block, cylinders 1-3 appear to be working perfectly. All cylinders are in the right position and the engine was running [badly] so there is no seizing. Cylinder 4 appears to be firing correctly, despite the marking to piston-top. Cylinder 5 appears to be firing ok, but there was a small pool of neat diesel in it. This may have just spilled over from cyl. 6 when the head was removed, as 5 appears to be firing.
Cylinder 6 was full of neat diesel to the brim. There was no sign of 'hydro-locking' or the neat fuel affecting the crank, so it seems to have been gushing straight into the turbo/exhaust. Exhaust-port 6 on the head is wet / oily with diesel, whereas the other 5 are bone dry and sooty, so it looks like only cyl. 6 was in fact not firing.
The top of piston 6 is quite badly corroded, as is the top of the combustion chamber in the head around the valves. I wonder if excessive fuel from a leaking injector could cause this?
Injector 6 appears fine [as is always the case].
There is no sign of damage to the head, cams, block, manifold and turbo, so I have to give the head a clean bill of health and will be putting it back on. New gasket is £80-£120 on its own!
No loss of compression on cyl. 6 or damage to head-gasket.
My best guess is that as exh. port 6 on the head is wet with fuel, no. 6 injector has flopped it in a big way and been flooding the back cylinder with fuel and not firing, which could still explain the sudden nature of the fault.
If this not the case, then I can only imagine the dropping swirl-flap has caused untold damage to the engine, knocked the timing out somehow affecting only cyl. 6 completely, but 4 and 5 to fire improperly too.
Yeah, so looking like a truly broken injector then! Guess I will be replacing all 6 when I refit, about £40 each, along with some swirl-flap blanking-plates for £7.50. I also broke the thermostat-housing as I removed the feed-hose, so that's another £40 down the drain, oh and more oil and coolant of course. Think I'll re-use the head-bolts!
Image resized to 50% of its originalize [1600 x 1200]
...because there is no sign of it in the head, or inside cyl. 4 / the exhaust manifold. The turbo is spinning great and there is no play in the spindle. You would imagine the flap getting stud behind the inlet-valves, right down the inlet-port, but there is just no sign of it. I got the inlet valves down using a home-made valve-spring compressor, built from a piece of angle-iron and an M10 nut/bolt and sent pipe cleaners through. There is no obstruction in the head at all. Ima
resized to 37% of its original size [1200 x 1600]
Slight marking on piston 4 suggest the flap has been mashed through the cylinder, or that the inlet-valves have gingerly contacted the piston while that was going on.
Image resized to 37% of its original size [1200 x 1600]
In the block, cylinders 1-3 appear to be working perfectly. All cylinders are in the right position and the engine was running [badly] so there is no seizing. Cylinder 4 appears to be firing correctly, despite the marking to piston-top. Cylinder 5 appears to be firing ok, but there was a small pool of neat diesel in it. This may have just spilled over from cyl. 6 when the head was removed, as 5 appears to be firing.
Image resized to 50% of its original size [1600 x 1200]
Cylinder 6 was full of neat diesel to the brim. There was no sign of 'hydro-locking' or the neat fuel affecting the crank, so it seems to have been gushing straight into the turbo/exhaust. Exhaust-port 6 on the head is wet / oily with diesel, whereas the other 5 are bone dry and sooty, so it looks like only cyl. 6 was in fact not firing.
Image resized to 50% of its original size [1600 x 1200]
The top of piston 6 is quite badly corroded, as is the top of the combustion chamber in the head around the valves. I wonder if excessive fuel from a leaking injector could cause this?
Image resized to 50% of its original size [1600 x 1200]
Image resized to 52% of its original size [885 x 1143]
Injector 6 appears fine [as is always the case].
Image resized to 50% of its original size [1600 x 1200]
There is no sign of damage to the head, cams, block, manifold and turbo, so I have to give the head a clean bill of health and will be putting it back on. New gasket is £80-£120 on its own!
No loss of compression on cyl. 6 or damage to head-gasket.
My best guess is that as exh. port 6 on the head is wet with fuel, no. 6 injector has flopped it in a big way and been flooding the back cylinder with fuel and not firing, which could still explain the sudden nature of the fault.
If this not the case, then I can only imagine the dropping swirl-flap has caused untold damage to the engine, knocked the timing out somehow affecting only cyl. 6 completely, but 4 and 5 to fire improperly too.
Yeah, so looking like a truly broken injector then! Guess I will be replacing all 6 when I refit, about £40 each, along with some swirl-flap blanking-plates for £7.50. I also broke the thermostat-housing as I removed the feed-hose, so that's another £40 down the drain, oh and more oil and coolant of course. Think I'll re-use the head-bolts!
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