Hi Guys, I have a 2012 Octavia 2 1.8 tsi. Injector keep popping out of head. It was resealed twice. Its original Vag. There is no fuel leak. Its the tip of the injector popping out of head damaging teflon seal. Teflon seal was seated and pressed into place with original VW tool. Aby ideas what this might be? Mechanic speculates that hole  where injector goes is rounded or bigger than it suppose to be. Aby help appreciated. Thank you.

Stick it in place with a little high temperature silicone.

Thank you.

You mean to apply layer od silicone behind the teflon seal around the injector? 

any recomendation which product should I use? 

TBH most silicones should be ok e.g. bathroom silicone sealant etc.

 

I would only apply a thin smear to clean uppermost contact surfaces and not down deep and internally or it'll be a PITA to work on at a later date.  If that concerns you try a small blob/bead around the exterior of the injector(s) to secure it to the manifold, again be sure things are clean for a good stick.