Stripped injector thread.

[vwmark]

Just my luck after a rubbish week in work and someone elses decision that means I have to find a new job, I decided to replace the injectors on my Mitsubushi Delica to get my mind off this.

Removed no.1 no problem but no.2 was tight and on removal can see why - part of the thread came with the injector.

No.1 had the flame washer missing so someone has already been poking around before.
What are my options?

 

[grim_d]

Thread insert.

You can get kits specifically for that and spark plugs.

Doesn't look too bad. I'd be very tempted to clean them up and give it a go as is, perhaps with a bit of high temp loctite.

 

[Barking Mat]

Locktite sealant? Of some description, or new head?

 

[vwmark]

Locktite sealant? Of some description, or new head?

I hope not a new head!

Worse case its remove the head and use an insert but just wondering what people had done.

 

[Pete.]

I'd insert that with the head in place.

 

[grim_d]

I'd insert that with the head in place.

Absolutely.

 

[vwmark]

Absolutely.

Access isn't briiliant but doable. Need to get last 2 out which are even further restricted. If they come out ok, I might try.

What inserts have people used?

 

[premmington]

I always make up a thread insert - little lathe job.

I have a set of monster old AF taps - so I have to get my dad to do the external thread cutting as my lathe only does metric.

Gonna be lost when my dad dies - even if I inherit his old lathe - I don't know how to use it.

 

[8ob]

Inserts are easy enough to fit Mark, take out the glow plug and fit an air line adaptor to it, bring said cylinder to tdc compression stroke and run the air while you tap it. Keep your mouth shut and wear decent goggles

Bob

 

[vwmark]

Inserts are easy enough to fit Mark, take out the glow plug and fit an air line adaptor to it, bring said cylinder to tdc compression stroke and run the air while you tap it. Keep your mouth shut and wear decent goggles

Bob

Thanks but... when you are tapping the chamber will be sealed so pressurising wont make any debris come out or am I missing something?

I was just going to make an insert to sit where the nozzle goes but below the thread.

Just looked and cannot find any inserts. Xan you point me in the right direction?

 

[premmington]

Thanks but... when you are tapping the chamber will be sealed so pressurising wont make any debris come out or am I missing something?

I was just going to make an insert to sit where the nozzle goes but below the thread.

Just looked and cannot find any inserts. Xan you point me in the right direction?

I can never find inserts - only for spark plugs - this why I have to make mine for injectors.

There are not many threaded injectors left now - they are all common rail - which are clamped down.

 

[brightspark]

I always make up a thread insert - little lathe job.

I have a set of monster old AF taps - so I have to get my dad to do the external thread cutting as my lathe only does metric.

Gonna be lost when my dad dies - even if I inherit his old lathe - I don't know how to use it.

theres no such thing as an af tap. af stands for across flats the head of a bolt or nut

 

[roofman]

I used to play with these amazing trucks and engines in my past life...take the head off and do it right i say

 

[8ob]

Thanks but... when you are tapping the chamber will be sealed so pressurising wont make any debris come out or am I missing something?

I was just going to make an insert to sit where the nozzle goes but below the thread.

Just looked and cannot find any inserts. Xan you point me in the right direction?

You just made me go out in the cold to look

Thread size is M24x2mm and you can get them from here https://www.screwfasteners.co.uk/media/emails/catalogues-pdf/fixnvis/Bollhoff/en/HELICOIL-REPAIR.pdf

Crud from the tap will whistle up past the flutes in the tap , dont forget to get one of these in the glow plug hole and connect the air line.

 

[premmington]

theres no such thing as an af tap. af stands for across flats the head of a bolt or nut

Imperial taps I mean (I deal so little with imperial measurements) - I sort of have embeded in my mind - spanners - metric and AF.

 

[vwmark]

You just made me go out in the cold to look

Thread size is M24x2mm and you can get them from here https://www.screwfasteners.co.uk/media/emails/catalogues-pdf/fixnvis/Bollhoff/en/HELICOIL-REPAIR.pdf

Crud from the tap will whistle up past the flutes in the tap , dont forget to get one of these in the glow plug hole and connect the air line.

View attachment 196963

Thanks! I think 1st I will make a tap out of an old injector and try my luck.

Just been and looked at all my taps and dont have an m24x2.

 

[Pete.]

Thanks! I think 1st I will make a tap out of an old injector and try my luck.

Just been and looked at all my taps and dont have an m24x2.

You can't re-tap it with m24 because the ally you would be tapping is already gone.

Here's a used recoil kit on ebay:

https://www.ebay.co.uk/i/233283194624

 

[vwmark]

You can't re-tap it with m24 because the ally you would be tapping is already gone.

Here's a used recoil kit on ebay:

https://www.ebay.co.uk/i/233283194624

Sorry I meant re-tap to clean all the threads up as I think it looks worse than it is - i hope!

Thanks for the link. Thats the cheapest by a mile that you found yet I searched on ebay.

 

[mcostello]

Leave Your hood (from across the pond Guy) open so If the threads don't hold You don't ding Your sheet metal.

 

[Bill Edwards]

Those threads look completely shot, without any material left you can't just run a tap through and expect it to hold, never mind hold it for long.
If you're lucky it'll fail as you tighten the injector, but it may hold out for a little while - in which case combustion pressure will blow the injector out like a small but powerful missile.