ml 270 cdi injectors,ISSUES

[pault8084]

Hi,I've just bought a w reg ml 270 which was cheap due to number one injector leaking compression.I'd heard this is common and as it's the most accessible thought i'd tackle it.The whole of the top of the engine was covered in some black sealant which wasn't doing a lot apart from making my job harder.After removing the gunk i easily pulled out the injector and ordered new bolt,washer and clamp and cleaned injector on wire wheel.today i thought i'd run a tap through the bolt thread only to find no thread!!!I'm now faced with a problem.i tried to drill out clamp to 8mm but it's seriously hardened so do i chemical metal a 6mm stud in or tap the chemical metal for original bolt.Got to be worth a try before i take off head.Cheers in advance,Paul

 

[television]

I believe that there kits for this.
Wait for a techie to answer and welcome to the forum

Do a Google search "injector remove repair"

 

[colechelle]

most times we just drill and tap to a 10mm, drill the clamp out and its stronger then before!!!

 

[pault8084]

Cheers,just thought it may be a bit extreme and trouble drilling clamp.Will get a decent drill bit on it.Stupid idea having an m6 bolt.That's not "german engineering".Interested to see if there is a repair kit(maybe oversize stud reducing to 6mm)

 

[stumo]

Yeah there is a new/updated clamp, and it is forged steel, so I'd say that is what you got.

That "sealant" you speak of is actually a by-product of the leaking combustion gasses, aka "black death" - what solvents/method did you use to remove it?

 

[pault8084]

I chipped it off with a screwdriver and used brake cleaner.

 

[pault8084]

was going to tap out to m10,managed to drill out clamp but the 17mm head of the bolt is too big to turn when injector and clamp are in place.Needs to have small head on m10 bolt?????

 

[Number_Cruncher]

Use a socket head cap screw.

 

[kebo57]

was going to tap out to m10,managed to drill out clamp but the 17mm head of the bolt is too big to turn when injector and clamp are in place.Needs to have small head on m10 bolt?????

Sounds like you need a threaded insert but what size have you tapped the hole in the cylinder head after you drilled the old bolt out

I can make a insert with the 6mm internal thread & an out side diameter thread to suit the thread in the cylinder head (when our if you have tapped the cylinder head) this will get you back to the original clamp bolt thread

PS as per usual nobody says where they are located in there profile

Kevin

 

[pault8084]

Total i put an m8 helicoil in and new washer,tightened as much as i dared and started and it still blows by.Wondering now if i should just try and seal in injector.

 

[jibcl500]

I chipped it off with a screwdriver and used brake cleaner.

The best thing to remove this black varish is mr Muscle over cleaner. Comes up really clean.
jib

 

[kebo57]

Total i put an m8 helicoil in and new washer,tightened as much as i dared and started and it still blows by.Wondering now if i should just try and seal in injector.

"and new washer" is this for the clamping bolt our a new seal washer for the injector
You need a new seal copper washer for the injector & clean mating surfaces & make sure the 8mm bolt isn't bottoming out, check bolt depth with out the clamp

Kevin

 

[pault8084]

yeah new copper sealing washer and not bottoming out on clamp bolt.Must be down to injector seat cleanliness.Haven't got a proper tool to clean seat so difficult.Will have another fiddle tomorrow

 

[colechelle]

make sure its tight, 7nm + 90 +90!!!

 

[pault8084]

Cheers i will do it to that torque but i imagine tightness is not the problem.

 

[jibcl500]

Have you checked the injector isnt cracked!!!!??

Clean everything!!! the injector hole has to be as clean as possible ie nice and shiney !!!! anything else and you are wasting you time, the seals (copper washer) have had a part number change so they are fatter, so I assume the seals came from mercedes.

jib

 

[pault8084]

Yeah genuine washer.injector looks mint after being on wire wheel just struggling to get black crap out of injector hole,seat looks good but obviously not good enough.

 

[jibcl500]

I used a green scourer pad wrapped around a steel shaft and cable tied at one end, did the job, I also adapted the vacume with a thin rubber hose to remove the dust and crud whist cleaning.

jib

 

[colechelle]

that black crap gets into the screw thread, are you sure the thread is clean, otherwise your be compressing the bolt against the crap!!!

 

[jibcl500]

Good point coll. the thread is deep and with mine the bolt wastn't even touch ing the thread. cleaning the bolt hole is the biggest hassle due to width.

Curtain wire, that coiled steel, cut the end off so there is a small burr sticking out and then use that to dig into the crud, it works but its time consuming, WD40 helps too.

jib