Injector blown out, taking helicoil with it

morrow1980

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Well i think i`ve found my rough running problem, the very 1st injector popped out yesterday , inspected today it has took the helicoil with it, looks like a bad repair by someone, the injector itself has a long crack on the bottom section , i`m guessing this has been the cause of it running rough and smoky.

Big question is the threaded part repairable, or will i need a new cylinder head,see when people change the injectors, whats the issue with the bolts ?as in why do people not use the original stretch bolts?, mine has what looks like threaded bar with nuts holding the injectors in, the 1st injector actually had a bracket as well bolted onto the rocker cover, so who ever fitted it obviously new it wasn`t seated right.
 

bob 6600

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Looks like someone has done a right bodge job on yours! The helicoil repair was not done correctly as it should hold it fine. The point of using an insert is so that the correct (stretch) bolt can be used. I'm sure it can be repaired, mine was bodged but now has an M10 s/s hex headed bolt which has held the injector in place fine for over 2 years
 
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morrow1980

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fingers crossed it can be mended, i`ve never saw an injector so badly cracked either, i`m thinking all the injectors need re-doing properly, they have all got tool marks on them as if someone has been using mole grips to force them in, least i now know what to look for in ml270`s i`ve learnt the hard and expensive way ,

Would a cracked injector cause lots of smoke and rough running ?

still curious as to why it failed, 1st the turbo now this i`m wondering if there`s a link or if it`s all down to bad luck and poor repairs
 

Blobcat

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I know I've posted this before, MB Dealer did this to an ML belonging to a contractor that worked for me, his ML went up in flames on the M4 because the injector blew out under pressure spraying fuel over the hot exhaust and that was the end of his ML.
 
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morrow1980

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mine was very close to doing just that yesterday, a shame as would have been able to buy a working one
 

bob 6600

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The molegrip marks were probably from removing the injector. Also, they seemed to have just kept tightening it trying to get it to seal and cracked the injector. Yes it could well be the cause of smoke and rough running.
 


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