Sorry to hear that
Sorry to hear that
Below, The dented head
Piston 2 on the right seemed to have the most damage overall, it also has loads of little dents over the whole head which the others didn't have,
Piston 1 looks very clean and has the odd cleaner patch towards the rear, the others also ha this in the same place but not as dominant, probably due to the oil that was covering them.
The big chunk was pulled from piston 4, the little chunk was taken from the head of piston 4.
Piston 4 with the dent where the object was removed and the bad scoring going down the bore.
Pistons 1 2 3,
Pistons 2 3 4.
I hope someone can guide me on this,
Last edited by Bren; 10-07-2004 at 21:02.
there are a few marks on the top of piston 1 , they may have been a part of some previos damage 3 years ago, I cant remember for sure.
ps, sorry, I forgot the resize one picture so its come out quite big
no signs of detonation then, good.
as for the object, at first glance it looked exactly like one of the metal dowels from an XE/LET sump gasket.
realistically it can only be something from the turbo, throttle body or valve train.
I dont know what to look for with regards to detonation but I'll agree with what you say, cheers.
I double checked the air filter, there are no signs at all of any tears or gaps, Its only done 500 miles and is still like new.
So the object like you say has come from something breaking on the engine / turbo etc and not from outside.
I'm gonna borrow a mates valve spring compressor and strip the head in the next few days, this will let me see if the guides have bust.
The scored head, is this going to need boring and then oversized pistons fitting?,
If it does need doing Is it much more money (and worth the while) to have it taken to a 2.1 litre or bigger?.
personally i would just go up a piston size, so 0.25 oversize, or basically whatevers needed to remove the scores. going to 2.1 is overkill, especially on a LET, which by design is mimicking larger engine capacity with turbo boost. theres no need to take the block to the limits just for physical capacity. nicer to have a bit more meat between the cylinders i reckon.
the flipside though, pistons are the same price regardless of size between 86 and 88. if you had another failure on 88mm pistons youd have no room to overbore again, but having said that it would be cheaper to get a new block than buy new pistons and have another small overbore.
thanks odders, I'd prefer to keep the block a little stronger like you say, I'll go for the smallest overbore possbile then.
ouch that doesnt look good.you had a chance to strip the turbo down yet?as when you started having problems it started with lack of boost right?turbo could have broken up inside? or possibly droped a collet?unusual but i have seen this before.also take a look at the injectors
TBH that looks like severe Det on those pistons
Sir, please step away from the car
I also thought this. SEVERE det,which is quite possable on a turbo engine especially.Originally Posted by RDS
not detonation.defenatly not.u wouldnt get such severe damage as oddball pointed out
is the clean patch on one side of the piston where the injector is squirting?
theres a picture of detonation on page 1. its not so selective that it will make a few large dings in the piston. plus the fact he found an object imbedded IN the piston.
could the small object not be the nut from the turbo which has been chewed uop as its gone through the blades therefore ending up in more than 1 piston. just a thought probley bollox but could be something to think of
I have stripped the turbo down with skelly, neither of us know about turbos so we just kept undoing all the nuts we could find,
The inlet side of the turbo was fine, it had a little play though so we carried on and then found the problem,
I dont know what caused the blades to tear off but it did in one place and then took a lot of the remaining blade ends off and sent them into my engine, hence, knackered engine.
Any ideas what could have caused this blade to break up for future reference?
I was boosting at around 16-17 psi, I was also touching 150 MPH in 5th which doesn't really help, but its been fine all the other times.
My plan was when the turbo went to upgrade to a hybrid, I never planned on having a rebuild to pay for as well though,
Any ideas about what turbo I should consider buying without blowing a lot of cash?.
Pictures now uploaded,
The first blades are fine,
The second set have a big chunk missing which has clipped the outer edges of the rest of the blades just to finish the job off with style.
so is the top pic the compessor, and the bottom the exhaust turbine ?
looks like whatever was in the cylinders made its way down the exhaust then.
Ahh, I never really thought about it but yes, I presumed this had broke and gone into my engine,
but what you say is that what was in my engine has come out and broke this afterwards, thats bad then cos i'm back to stage 1 at knowing the original cause.
not really. just means its made the full circuit, from inlet or cylinder, right out the other end.
so could this have broken up and gone into my engine?,
if you are asking wether the blades from the exhaust turbine could get into the cylinder, upstream of flow, and past the opening and closing exhaust valves. not a chance in my opinion.
hmmm, do you know if there Is any other part of the turbo that could break up and be drawn in or should I now be looking at the inlet manifold and head for the cause?.
I have pretty much stripped the turbo down and everything else looks fine on it.
is there not a nut missing from the centre of the compressor (top picture) as suggested by a couple of people earlier in the thread ?
Please, please make sure you check the inlet valves guides. I had virtually the same looking symptoms on Janes XE. I rebuilt the bottom end, and put the cause down to be a washer being dropped into the pug hole at some point. After it'd run back in and went on a long drive the same thing happened. I stripped the head and found that 4 1/2 valves guides had cracked and broken up.
I'll have a look for a pic of the piston when that happened. The nut idea may be a good one too!
There are two things no man will admit he cannot do well: drive and make love.Stirling Moss.
yeah all good guesses. guides dont usually give up unless the valves have taken a knock though. and the picture of one of the bits on the stanley blade is perfectly disk shaped. but the marks inthe pistons arent.