110 cdi cyl head helicoil engine problem

[simonnite]

have the above at 124k, engine is blowing thro side of area near glow plug, so much rock hard caked on burnt oil cannot see damaged area, could failure be due to head having a helicoil when thread was stripped removing a glow plug?
Help and advice would be appreciated as not sure this is terminal?
thanks
simon

 

[Blobcat]

Yes could very well be caused by heli-coil. If the glow plugs were changed by a garage I would take it back to them and get them to fix it.

 

[simonnite]

thanks blobcat, helicoil was done a while ago by main agent, so want to find out if helicoiling head is a recomended fix by MB? to my concern they also helicoiled the head with it on the engine...

 

[Blobcat]

Helicoil is a dealer fix, although it should be that a 'Fix' and not a temporary one. Have them fix it now.
A contractor I use ran an ML270 which had an injector problem, dealer took it in and damaged the head taking the injector out. The dealer then had another garage helicoil in a new injector (could'nt do it themselves). Due to the massive fuel pressure in the CDI engine the helicoil failed quite spectacularly on the M4. The driver just had time to get out before the whole vehicle was engulfed in flames. Cost the dealer quite a bit that did.

 

[simonnite]

thanks blobcat; Have now had a chance to look at it more closely and having chisseled thro the black stuff it would appear that there is a hole near the base of the injector body so it puffs out diesel and oil especcially under load, I assume this is the correct diagnosis as it didnt seem to be loosing power which it would do if there was a hole in the head?

 

[Blobcat]

From what you have found I would take it straight back. Only speak with the serivice manager and ensure they fix it pronto (and FOC).

 

[simonnite]

curiosity got the better of me, managed to chisel thro a lot of crust to find that injector waggled around by about 0.3 mm at top, removed injector to find hairline crack along bottom section running parallel to centre line.
how is injector meant to seal against head as it is obviously (now!) just tracking up injector shaft and belting out of the top, and prob has been for ages.

 

[Blobcat]

Any pictures?

 

[simonnite]

hi blobcat, will take some pics tomorrow, have started new thread as I have now narrowed it down to injectors!, crack is just visible' so should show up.Will prob take all of them out and replace seals, will phone merc for more info re these.