2009 Vito injector still blowing/stripped thread

[Alex1991]

Hi all
I’m new to the forum, I’ve signed up to ask for some help/advice if that’s ok
My 2009 Vito 109 cdi had terrible black death. I took all the injectors out and cleaned it right up, reinstalled all with new seals and bolts but the injector which was the problem still leaked. I used a re-seating tool and did it again…twice, I even heated up the copper seal, and still leaking. So I thought the stretch bolt might not be clamping down far enough so I cut it down by a few threads, this caused the thread to strip in the cylinder head. So I’ve had a right nightmare and feel a bit stuck now. The van is solid otherwise but not worth spending a fortune on, will a heli coil be ok for the stretch bolt hole? And if so does anyone have any ideas about the blowing injector seal? Thanks a lot in advance

 

[StMarks]

Hi all
I’m new to the forum, I’ve signed up to ask for some help/advice if that’s ok
My 2009 Vito 109 cdi had terrible black death. I took all the injectors out and cleaned it right up, reinstalled all with new seals and bolts but the injector which was the problem still leaked. I used a re-seating tool and did it again…twice, I even heated up the copper seal, and still leaking. So I thought the stretch bolt might not be clamping down far enough so I cut it down by a few threads, this caused the thread to strip in the cylinder head. So I’ve had a right nightmare and feel a bit stuck now. The van is solid otherwise but not worth spending a fortune on, will a heli coil be ok for the stretch bolt hole? And if so does anyone have any ideas about the blowing injector seal? Thanks a lot in advance

Hi Alex, from a fellow "Vito Victim" .. Mine also had black death when I purchased it. Fwiw you're braver than myself, as I read up extensively and came across far too many horror stories of failed attempts ending in disaster. I cleared back the deposits myself, but entrusted the actual replacement to an MB dealership. Even so, one of them leaked again about 10 months later (which they did again at no charge).
Obviously the seat must be totally clear, otherwise a new copper seal won't work for long. However I do recall also reading that Honda make some injector seat washers that "are more processed & therefore seal can more effectively"
There are a few other Vito owners on here, but with considerable knowledge, and the 2.1cdi engine was also used in various other Merc's, so hopefully you'll get some more constructive advice in due course..
Good luck.

 

[Alex1991]

Hi Alex, from a fellow "Vito Victim" .. Mine also had black death when I purchased it. Fwiw you're braver than myself, as I read up extensively and came across far too many horror stories of failed attempts ending in disaster. I cleared back the deposits myself, but entrusted the actual replacement to an MB dealership. Even so, one of them leaked again about 10 months later (which they did again at no charge).
Obviously the seat must be totally clear, otherwise a new copper seal won't work for long. However I do recall also reading that Honda make some injector seat washers that "are more processed & therefore seal can more effectively"
There are a few other Vito owners on here, but with considerable knowledge, and the 2.1cdi engine was also used in various other Merc's, so hopefully you'll get some more constructive advice in due course..
Good luck.

Thank you for the reply. The Honda seal is a good bit of advice I’ll look into that. I’ve also now got the issue of the stripped thread. Nightmare

 

[StMarks]

... I’ve also now got the issue of the stripped thread. Nightmare

I've used helicoil thread repairs numerous times. Not on my Vito cylinder head, but on similarly critical situations on other engines.
I personally do not see any reason why it would not work just as well in that situation.? **
Afterall it's the stretch bolts that are the "unusual variant", not the hole it threads into.
Obviously you'll need to be very careful not to drill any deeper than the O/E hole, and retrieve every crumb of swarf.



** Edit, subject to more knowledgeable forum members advising otherwise...

 

[carat 3.6]

It sounds like the seat wasn't re-cut properly, or with the correct size cutting tool.

The proper approved way to repair is with a helicoil and new stretch bolt, however I have in a few case's moved up to 8mm cap screw with great success. The Honda washer is softer but is also thicker, so as you have recut the seat more than once you will need it.

 

[Alex1991]

It sounds like the seat wasn't re-cut properly, or with the correct size cutting tool.

The proper approved way to repair is with a helicoil and new stretch bolt, however I have in a few case's moved up to 8mm cap screw with great success. The Honda washer is softer but is also thicker, so as you have recut the seat more than once you will need it.

Hey thanks for the reply I feel better about the screw now. I’ve ordered a Honda washer so fingers crossed!

 

[m80]

Some of the seat cutters don't reach the seat.
The shoulder needs grinding off to enable it to go deeper.
Was there swarf to remove after cutting?

Then there is the condition of the injector flange.

 

[toteimerced]

Have a look on YouTube for relevant videos, there’s plenty.

 

[Alex1991]

Some of the seat cutters don't reach the seat.
The shoulder needs grinding off to enable it to go deeper.
Was there swarf to remove after cutting?

Then there is the condition of the injector flange.

Sorry could you elaborate on grinding the shoulder off? There was swarf but I hoovered it out with a tiny hoover attachment and cleaned it thoroughly with solvent wipes multiple times. I have a little inspection scope/camera and it looked immaculate to my eye but I couldn’t guarantee the seat is flush if that makes sense

What about the flange?

 

[m80]

If you had swarf you were cutting the seat. So you can ignore the shoulder issue.

I spent hours trying my 1st cut, made no difference as the seat cutter was unable to go deep enough into the hole.
Like you I use a digi camera, and enlarge on the pc to inspect the seat.

So is the meeting flange of the injector damaged.