S3 2.25 petrol BANG! Help/opinions/yada please?

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Turn the engine over push it back up and a few self tappers in it to get a hold of, I bet you can pull it out.

The bottom has to come off anyway, I was saying take it out from what you had as you had something to get hold of.
Plus then we can all see whats happened ;) .

J
Exactly the plan. That's why I asked how thick the crown is.
Or a long drift from the bottom.
Your next dramatic instalment is tomorrow.......
 
Apart from the initial bang was it noisy? As in death rattle, spinny things thrashing the insides to pieces type of noise. If the little end broke I would expect ALOT of noise and the engine to be scrap but if it snapped around the wrist bit at the big end then it could be OK. Piston gets stuck at the top so the remains of the conrod are out of the way of the crank and the rest is still attached to the crank.

I need to know, get out there now and take it apart 😆
 
Very impressive have you confirmed if piston still connected to conrod and or crank by turning crankshaft
by hand, agree with coming out of top , sump off and long bar from bottom with 4lb club hammer and nudge it out
 
Turn the engine over push it back up and a few self tappers in it to get a hold of, I bet you can pull it out.

The bottom has to come off anyway, I was saying take it out from what you had as you had something to get hold of.
Plus then we can all see whats happened ;) .

J
Agree a self tapper bolt with the cutting bit on the end drilled in then a claw hammer and a block of wood to ease it up would be the way I would go...
 
UPDATE !
Having finally found the time to get the sump cover off, I now find that the piston is detached at the top, and the gudgeon pin is still attached to a ring of aluminium. Bottom end appears undamaged. Pics to follow.....
Any suggestions as to why?
 
Has the piston started to melt!? What do the rest look like?
Nope, no melting or any other classic stuff. The rest have a little coke build-up and nothing else, and there is almost no discernible bore wear or a lip that might catch. When I get the piston out I'll know more....
 
Apart from the initial bang was it noisy? As in death rattle, spinny things thrashing the insides to pieces type of noise. If the little end broke I would expect ALOT of noise and the engine to be scrap but if it snapped around the wrist bit at the big end then it could be OK. Piston gets stuck at the top so the remains of the conrod are out of the way of the crank and the rest is still attached to the crank.

I need to know, get out there now and take it apart 😆
See below! Conrod seems fine.
 
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What fuel have you been running and how many degrees set on the dizzy?
Yeah, I was thinking that. It should be smack on standard, whatever that is, but I shall check. If it's been detonating/over advanced I'll replace all four pistons, but at the moment I don't see any evidence for that. The dizzy is reputable, new-ish, and electronic.
Weird.
Unleaded BTW.
 
4 star was 98 ron so similar to what we call super (which is also e5) normal unleaded in 95 so you'll want to advance a couple of degrees.
The more important thing is getting the mixture right, too lean and it will burn hot
 
UPDATE !
Having finally found the time to get the sump cover off, I now find that the piston is detached at the top, and the gudgeon pin is still attached to a ring of aluminium. Bottom end appears undamaged. Pics to follow.....
Any suggestions as to why?
You will be able to answer that better when you get both bits out, most likely initiated as creep forming a small crack which propagated to a bigger crack until bang!
pics will be interesting but with the gudgeon pin kept away from cylinder walls bores may not be to bad
 
OK Forensics Team - tell me what you make of this:-
1: Bore is OK I believe. :)
2: Bottom end is OK I believe.
3:Engine spins freely.
4: Self-tappers & claw hammers work to extract piston crowns (it wasn't tight).
5 Measure up and new piston time!

For your delight and amusement:
 

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You will be able to answer that better when you get both bits out, most likely initiated as creep forming a small crack which propagated to a bigger crack until bang!
pics will be interesting but with the gudgeon pin kept away from cylinder walls bores may not be to bad
Looking at the piston, it seems like one quadrant has been fractured at the top ring groove for some time before the final failure. See the pics below.
 
4 star was 98 ron so similar to what we call super (which is also e5) normal unleaded in 95 so you'll want to advance a couple of degrees.
The more important thing is getting the mixture right, too lean and it will burn hot
It's been running quite rich judging by the plugs/crowns/valves.
 
Looking at the piston, it seems like one quadrant has been fractured at the top ring groove for some time before the final failure. See the pics below.
So how confident the others are not the same?

Full set for me TBH.

Your in it now far enough to make it easy.

J
 
Blimey. Has it overheated or had an oil starvation problem?
Hypothesis.. running too rich for too long.. piston ring seizes from deposits.. ring expands, can't move in the way it should and shatters the piston.

??
 
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