Injector hold down bolt

[Gary007]

Hello everybody just after some advice on my mercedes 2.1 vito w639 I have cleaned all the carbon of the engine I have managed to do two injectors seals I have got the third and fourth to do but I'm stuck with the third bolt hole thread the bolt won't tighten I have cleaned it well hovered all the carbon out of the hole please could someone help me out what do i need to do and were do i buy what I need any direct links ect thanks gary

 

[alexanderfoti]

If the bolts don't tighten then the threads are probably stripped. The rocker cover needs to come off and the holes drilled out and the thread repaired (timesert is my preferred method)

 

[EmilysDad]

.... (timesert is my preferred method)

Likewise ... far better than Helicoils

 

[Kev555]

Not a lot of room to get at injector area on 3 and 4 if your engine is the same as mine. I removed the scuttle panel and wiper linkage on mine when injector 3 was siezed to make life a bit easier. 4 is still awkward either ways if you have any issues. Just a suggestion if you haven't already done that.

 

[Gary007]

Not a lot of room to get at injector area on 3 and 4 if your engine is the same as mine. I removed the scuttle panel and wiper linkage on mine when injector 3 was siezed to make life a bit easier. 4 is still awkward either ways if you have any issues. Just a suggestion if you haven't already done that.

I have got injector number 4 out by turning engine over like you I removed the window wiper scuttle tray but no joy so I lubricated the top of injector around were it sits in head left over night them did the dead which after a couple of turns on the key it came out but I'm now trying to solve the bolt hole thread on 3 just so much info on it

 

[Kev555]

Nice you got your injectors out Gary, I had to fork out £170 to a specialist to hydraulically remove one. Alexanderfoti above is a wealth of knowledge and he along with others have guided me through thick and thin with my Vito. If he says timeserts then timeserts it is. at least with number 3 theres a bit more room to work.

 

[Kev555]

Steve@aventgarde has a wealth of knowledge too about proper replacement of injector bolts iirc. remember to reseat your injectors or washers will possibly blow by again in a short space of time. Give injector bodies a coat of ceramic grease before replacing if possible as this apparently stops them bonding into injector wells again in case of a repeat

 

[ajlsl600]

Hello everybody just after some advice on my mercedes 2.1 vito w639 I have cleaned all the carbon of the engine I have managed to do two injectors seals I have got the third and fourth to do but I'm stuck with the third bolt hole thread the bolt won't tighten I have cleaned it well hovered all the carbon out of the hole please could someone help me out what do i need to do and were do i buy what I need any direct links ect thanks gary

helicoil is wot u need practice on a bit of scrap first . its not hard. be very clean around the area of repair

 

[ajlsl600]

https://www.cdiscount.com/bricolage...tml?idOffre=471744770&ef_id=EAIaIQobChMI2vrVt
.
just a quick search ,i suspect yr looking 8mmx1.25 but check that with a removed bolt. 8mm is o/d and 1.25 is the pitch of the thread , ridge to ridge . this can be measured with a vernier or if avail thread guage. if yr not reasonale confident this better left to someone else tho its really not difficult .

a PROPERLY installed helicoil in my experience is bullet proof , do not waggle about the drill bit for the tap the helicoil will not be installed to its designed tolerances

 

[EmilysDad]

helicoil is wot u need ...

As above ... Timeserts are much better than Helicoils

 

[Gary007]

If the bolts don't tighten then the threads are probably stripped. The rocker cover needs to come off and the holes drilled out and the thread repaired (timesert is my preferred method)

 

[Mark A]

+1 for timesert

 

[Gary007]

Ok thanks for the response everybody I will take rocker cover of and go from there makes sense when you think about it I did do the third injector when I first attempted it and it was fine but the fourth was bubbling so took I it out again to gain access so I think it will be a timesert does anybody have a link to what size is best also do i use the original 6m bolt new of course. The van as been sat on my drive for 2 years so the way things are I think I got the time to make a restart on it seeing thou I have spent so much time converting it into a viano from a panel thanks again everybody and stay safe

 

[EmilysDad]

You use a specific tap to cut the thread for the M6 insert, screw the M6 insert into the hole you've just cut so you can use a M6 bolt as before.
Like this ... https://www.amazon.co.uk/TIME-SERT-Metric-Thread-Repair-1610/dp/B001JK802K though this is out of stock ... but you get the idea

 

[EmilysDad]

....

a PROPERLY installed helicoil in my experience is bullet proof , do not waggle about the drill bit for the tap the helicoil will not be installed to its designed tolerances

In the case of this injector, a Helicoil would probably be OK ie an application where the recut thread has something screwed into it once. However in applications where the bolt is routinely removed & replaced, then I've known Helicoils to unscrew, where the Timesert, being a solid insert, tend to stay put.

 

[Gary007]

You use a specific tap to cut the thread for the M6 insert, screw the M6 insert into the hole you've just cut so you can use a M6 bolt as before.
Like this ... https://www.amazon.co.uk/TIME-SERT-Metric-Thread-Repair-1610/dp/B001JK802K though this is out of stock ... but you get the idea

Ok that's brilliant advice thank you

 

[Gary007]

Thanks for that that brilliant just what I'm looking for

 

[Blobcat]

In the case of this injector, a Helicoil would probably be OK ie an application where the recut thread has something screwed into it once. However in applications where the bolt is routinely removed & replaced, then I've known Helicoils to unscrew, where the Timesert, being a solid insert, tend to stay put.

I’ve known a helicoil blow out of an ML270, sprayed fuel over the exhaust and woof the car was a burnt out wreck

 

[EmilysDad]

This isn't a bad video ... Timesert vs Helicoil

I wonder why he doesn't use the little hole in the handle of the tap wrench to tighten/slacken it instead of using pliers

and I use a blob of Loctite on the outside of the insert to make sure it's going to stay put.

 

[ajlsl600]

In the case of this injector, a Helicoil would probably be OK ie an application where the recut thread has something screwed into it once. However in applications where the bolt is routinely removed & replaced, then I've known Helicoils to unscrew, where the Timesert, being a solid insert, tend to stay put.

get you . i have also seen cat inserts which are also solid they have hard tangs which you drive into the sides to prevent rotation , frankly i have never been a fan of those . i have also seen helicoils wind out .tho so far not mine , i believe its an installation issue . i have seen the utube timesert thing seems similar to where i have previously drilled out ,where space permits a much larger hole and locktighted a ,eg 7/8 unf bolt ,cleaned off the bolt flush and centre drilled that for ,say a 12/14 mm bolt ,again,where room/access allow . to date ,when working in alli i almost always helicoil any threaded fittings following which i have yet to have to repeat the exercise