Vito injector bolts!

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Sleazydisco

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Hi there, I’ve lost count on how many times I’ve done the injector seals. I have a 2004 2.1 115 Vito and someone told me there is a oversized bolt kit for holding the injector clamps down??
I can’t find them myself anywhere? Does anyone know if this is available as the bolts used are so inadequate of what’s needed.
Tia
Dan
 

Mark A

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You may need the injector seats or the sealing area on the injectors themselves dressed off. Doesn’t matter how good the washer is, if the surfaces aren’t reasonably flat it won’t seal for long.
 
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Sleazydisco

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Steve@Avantgarde

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Everything is ok in that document except for using the Honda washer. The MB washers are more than sufficient for sealing, its the clean up and cutting that will provide the seal to the head from the injector and nothing to do with the thickness of the washer.

There is no oversize bolts to use. The original M6 stretch bolts must be used at all times. The reason for this is as the engine gets hot the thread around the bolt will expand. Using the stretch bolts allows for this and will expand with the thread and keeping torque on the clamp.

When threads are drilled out to M8 and then a 8.8 or 10.8 tensile steel bolt is used the alloy engine will expand at a faster rate than steel, this will cause a loss of torque and therefore a loosening of the seal and then a leak. In extreme cases (and I have seen this) the bolt will loosen enough and the injector will fire out of the cylinder under compression.
 
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Sleazydisco

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Everything is ok in that document except for using the Honda washer. The MB washers are more than sufficient for sealing, its the clean up and cutting that will provide the seal to the head from the injector and nothing to do with the thickness of the washer.

There is no oversize bolts to use. The original M6 stretch bolts must be used at all times. The reason for this is as the engine gets hot the thread around the bolt will expand. Using the stretch bolts allows for this and will expand with the thread and keeping torque on the clamp.

When threads are drilled out to M8 and then a 8.8 or 10.8 tensile steel bolt is used the alloy engine will expand at a faster rate than steel, this will cause a loss of torque and therefore a loosening of the seal and then a leak. In extreme cases (and I have seen this) the bolt will loosen enough and the injector will fire out of the cylinder under compression.

Thanks again, I’ll keep to the m6 stretch bolts and give up on finding an oversized one, although could you replace with a m8 alloy bolt?
 

Westheath

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Hmmm
I've repaired more injectors shot out due to the useless oem bolts stripping the threads out.

I use a Time Sert repair with M8 Allen Key bolts and never had one comeback ever.

When replacing the oem fragile silly skinny bolts I was getting plenty coming back,
even using the MB thread cleaning long tap tools they still fail to keep the injector in place correctly.
Mercedes are the only company I have come across to use such a useless application of retaining an injector,
and the reason why the black death is so synonymous with those engines using them.

Mercedes do not recommend use of a injector seat cutting tool,
they require the repair to be done by polishing any defects out of the seat with the correct tools supplied by them.

Also MB ceramic grease must be applied to the injector body but not the nozzle area.

I have been repairing diesel engines for over 30 years from all manufacturers and MB missed the quality control on the CDI engine fitting such a useless injector retaining bolt, its one of the oldest jokes in the game especially when trying to remove them :)

[moan off]

Been a bad day doing guess what ....................
 
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Sleazydisco

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Hmmm
I've repaired more injectors shot out due to the useless oem bolts stripping the threads out.

I use a Time Sert repair with M8 Allen Key bolts and never had one comeback ever.

When replacing the oem fragile silly skinny bolts I was getting plenty coming back,
even using the MB thread cleaning long tap tools they still fail to keep the injector in place correctly.
Mercedes are the only company I have come across to use such a useless application of retaining an injector,
and the reason why the black death is so synonymous with those engines using them.

Mercedes do not recommend use of a injector seat cutting tool,
they require the repair to be done by polishing any defects out of the seat with the correct tools supplied by them.

Also MB ceramic grease must be applied to the injector body but not the nozzle area.

I have been repairing diesel engines for over 30 years from all manufacturers and MB missed the quality control on the CDI engine fitting such a useless injector retaining bolt, its one of the oldest jokes in the game especially when trying to remove them :)

[moan off]

Been a bad day doing guess what ....................

Thanks for your input I’ve done one maybe two in mine with a helicoil but another that isn’t helicoiled is starting to leak again and it’s been done once already so a different fix is likely to be needed, just trying to find the best solution
 

mercedes13156

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Both Steve and Westheath are absolutely right. Steve is the guy for the correct fix by the book and he is absolutely spot on with his advice. Most of us (like me) don't have the resources on hand that Steve does, or live anywhere near Steve.

One of the bolts on my first 203 stripped out. Steve gave me the exact advice you see above. I live 400 miles away and it was repaired with an M8 timesert and a 40mm long round headed stainless steel M8 allen bolt. You also have to enlarge the hole on the injector fork to let the M8 bolt in. As predicted by Steve himself, it loosened off after a couple of months and started leaking again. I took it all apart and cleaned both the injector seat on the head as well as on the injector. I used a new washer which had been lightly polished on both faces. I screwed it all together with the ceramic grease and put a drop of threadlock on the bolt. I tightened that down to hand tight, then 90 degrees and because I didn't want to strip it again, just another 45 degrees instead of the 90 recommended. Once the engine was well up to temperature and the copper was soft, I gave it the last 45 degrees. As far as I know, it's still in there.

You need to use an round headed allen bolt because there isn't enough room to get a socket on an M8 hex bolt.
 

Westheath

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You can torque the Time Sert installed M8 bolt to 28nm or 20ftlb +45'+45'

:D

Cleaning kit, there's brass injector hole plugs to stop debris falling into the cylinders when cleaning/polishing the injector seats and black death crap from the rest of the camshaft cover and injector tubes.

cleaning.jpg
 
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Gary007

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Hmmm
I've repaired more injectors shot out due to the useless oem bolts stripping the threads out.

I use a Time Sert repair with M8 Allen Key bolts and never had one comeback ever.

When replacing the oem fragile silly skinny bolts I was getting plenty coming back,
even using the MB thread cleaning long tap tools they still fail to keep the injector in place correctly.
Mercedes are the only company I have come across to use such a useless application of retaining an injector,
and the reason why the black death is so synonymous with those engines using them.

Mercedes do not recommend use of a injector seat cutting tool,
they require the repair to be done by polishing any defects out of the seat with the correct tools supplied by them.

Also MB ceramic grease must be applied to the injector body but not the nozzle area.

I have been repairing diesel engines for over 30 years from all manufacturers and MB missed the quality control on the CDI engine fitting such a useless injector retaining bolt, its one of the oldest jokes in the game especially when trying to remove them :)

[moan off]

Been a bad day doing guess what ....................
Hello westheath I've got a mercedes van with the problem of the injector bolthole striped threads i have read loads on this with a lot of different ways of curing the problem would do you recomend using a bigger bolt and were would i get one with timesert also how would i install timesert do i use the wurths kit which I've looked at and seem expensive for one time use could you please give me some advise on whats best method to use please greatfull for any advice regards gary
 

Blobcat

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Hello westheath I've got a mercedes van with the problem of the injector bolthole striped threads i have read loads on this with a lot of different ways of curing the problem would do you recomend using a bigger bolt and were would i get one with timesert also how would i install timesert do i use the wurths kit which I've looked at and seem expensive for one time use could you please give me some advise on whats best method to use please greatfull for any advice regards gary
Please see This thread
 
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