injector nightmare

[Gazz270]

evening all,last week i had to have the ml on star for an unrelated injector problem (aam),but whilst it was on it kept coming up with an injector fault on number one,so rather than leave it i thought i would sort it sooner rather than later.
quick phone call to feather diesels £130 lighter and i have a recon injector,clamp,bolt and washer.
now the problem,i thought i would do while the engine was hot usually makes these jobs easier,started undoing the clamp bolt all nice and easy,got to the last couple of threads and all of a sudden the bolt shot out under great pressure followed by what can only be described as a high pressure steam cleaner.
i can safely say i wasn't expecting that,
any ideas whats happened or is that supposed to happen,i suppose i should have done it cold and then i wouldn't have had a 3 hour wait in casualty to have eyes bathed and cleaned (ouch),ive read loads of threads relating to injector replacement but never noticed this problem in them.

Gareth

 

[Mercsys]

????
So the bolt hole was pressurised, if this is the case, it can happen if the bolt hole was not clean and DRY when the bolt was last fitted, this can generate great pressure as the bolt is driven down the threaded hole and can actually do damage like creating a fisher to the water jacket in the head!! I hope not!

Note to self, Depressurise the cooling system when working hot!!

 

[Gazz270]

i can only assume the injector has been done before and damaged when replaced,ive had a look down the hole and squeezed the top hose and it blows water out,it must have sealed itself when the bolt was last put in.

Gareth

 

[BlackC55]

I have had this happen to me. The bolt hole has been repaired before and they have drilled into the water jacket.

This is not good news really. For the correct repair the cylinder head has o come off.

 

[Mercsys]

... I have never seen a water jacket that has threaded holes "sealed" by the bolts themselves! Seems like a broken bolt was drilled out without sufficient care. Perhaps consider a repair of some kind prior to replacing the bolt. A very short grub screw at the bottom of the drilling/taping beyond the inj bolt end followed by a drop of one of the thread locking/sealing products. But you must not drop the repair screw into the water jacket!!!

 

[Gazz270]

ive just cleaned everything up and am going to inject chemical metal down to the bottom of the hole and then smear the threads in it before screwing it in,
it will be a one time only repair i think,nothing to loose i suppose.

 

[Gazz270]

... I have never seen a water jacket that has threaded holes "sealed" by the bolts themselves! Seems like a broken bolt was drilled out without sufficient care. Perhaps consider a repair of some kind prior to replacing the bolt. A very short grub screw at the bottom of the drilling/taping beyond the inj bolt end followed by a drop of one of the thread locking/sealing products. But you must not drop the repair screw into the water jacket!!!

ooh i never thought of the grub screw,good idea.
hope i can find one now,

 

[BlackC55]

ive just cleaned everything up and am going to inject chemical metal down to the bottom of the hole and then smear the threads in it before screwing it in,
it will be a one time only repair i think,nothing to loose i suppose.

That is exactly what I did as it was for a trader and he asked me to try anything to stop it leak!

It worked too btw

 

[Mercsys]

Careful with the product you select, some are “permanent/locking”, and they are good. the inj bolt will be irretrievable.

 

[Gazz270]

change of plan,i am going to cut 5 mm off the old bolt and put a slot in top smear that with chemical metal,

 

[Dieselman]

Epoxy glue will do the job of sealing the water. In my misspent and broke youth, I Araldited a leaky core plug that was hidden behind the engine mount.

Worked a treat.

 

[Mercsys]

There is a reason that threading is soooo deep, and you WILL be replacing the inj bolt, so the plug bolt just need to be beyond the finished depth of the inj bolt.

 

[Gazz270]

so far so good,ive put a couple of washers on the bolt so it doesn't foul on the bit ive put in the bottom,its all tightened down and torqued up,think ill leave while morning before i try it,ill not sleep tonight for wanting to try it out,

 

[Gazz270]

solved for now

done a 90 mile round trip today and so far so good,
went the grub screw route with chemical metal and a bit of instant gasket,
dont fancy my chances of getting it back out though without taking head off.
Also i dont know what the problem was with the injector flagging a fault on star because i never noticed anything while driving but it definitely feels smoother whilst driving now.

thanks for the help and advice guys.

Gareth

 

[silver_star]

done a 90 mile round trip today and so far so good,
went the grub screw route with chemical metal and a bit of instant gasket,
dont fancy my chances of getting it back out though without taking head off.
Also i dont know what the problem was with the injector flagging a fault on star because i never noticed anything while driving but it definitely feels smoother whilst driving now.

thanks for the help and advice guys.

Gareth

Fingers crossed the injector seal doesn't go.

 

[Gazz270]

if it does the cars going with it,