Thread lock on helicoil (diesel cylinder head)

[Paulbarrett]

Have the father in laws Audi in as the garage don’t want to know.

Long story but one Injector to has decided to evacuate the head. The hold down bolt has ripped its threads out the cylinder head. My thoughts are it was over tightened and just left. He’s had problems on tickets with the car but just heeds it running.

I’ve managed to drill and tap for a long m6x1 helicoil. Thread is 20mm deep.

I’m wondering wether to add a little red loctite to strengthen the situation

Any thoughts greatly recieved

It’s an Audi A6 3.0 tdi btw 2011

 

[hotponyshoes]

How much material do you have around the hole?
I'd fit a keensert..

To answer the question,
Bollhoff (makers of helicoils) say No threadlock.
Henkile (makers of locktite) say Yes threadlock.
So, take your pick

 

[Munkul]

loctite between the hole and the helicoil itself, why not, but absolutely not between the bolt and the helicoil itself.

If you've already fitted the helicoil, I'd think that would be well strong enough anyway. I'm assuming it's a blind hole, so as long as it's fitted properly... job jobbed

I think I'd only want loctite on a helicoil if it was an open hole and the thread was used regularly, ie for a guard bolt or something like that.

 

[JOEPRO]

I always use a dab of threadlock between a helicoil and the parent material. Then clean the new threads with a cotton bud before fitting new bolt.

 

[Paulbarrett]

I haven’t fitted helicoil yet as waiting for longer ones to arrive. But going from you guys I’ll be putting some red on the helicoil and clean it off the threads prior to fitting bolt

 

[T5 TDI]

Do the injector bores in the head look ok? The injectors often start fretting on one side because of the way they are held down with only one bolt. If so that might have contributed to the bolt breakage. There is brace available to help with the problem but it's really for a new head (to stop it happening again). Not sure if one is available for the 3.0 though or even if they are affected.

 

[T5 TDI]

Just realised yours is a CR not a PD so probably not afftected.

 

[doubleboost]

I have installed hundreds all dry .
Time sert is a better option but more expensive
It also needs a bigger hole sometimes a issue .