When I removed my sump guard on my 2020 Evo 4T one of the rear fixing bolt helicoil inserts partly came out with the bolt. This has been impossible to refit correctly and resulted in damaging any bolt that I use to refit the guard. I have removed the old helicoil but I’m a bit weary to fit a replacement I have as it looks like it might use a different thread to secure the helicoil in the frame. Anyone else had this problem and did they find a make of helicoil that fitted straight into the original threaded hole without retapping?

All the sump securing screws are M8 coarse thread with a 1.25 pitch. So any coil insert for M8 should screw in unless the cross-sectional form is different. So If you have some inserts, why not try one, you can always pull the wire out again. I've found that Vee-coil will fit. Don't knock the tang off until the insert is sufficiently just below the surface of the hole so that the bolt thread will start ok. 

I have had that issue at least twice.  Each time, the threads that hold the helicoil were damaged and attempts to replace it with a new helicoil failed to hold.  I used an E-Z-LOC to repair.  See link.   There are a number of companies that make things like this but if I recall correctly this was the only one that would fit.  The others had a larger OD and there is not enough material in the frame to go much larger.  

I'm now very careful to keep bolts into helicoils tight so they do not get a chance to move around a create damage.

 https://www.amazon.com/E-Z-LOK-Threaded-Insert-M8x1-25mm/dp/B00208KRQ2

The helicoil brand inserts fit.

Cheers Guys some useful answers there. Many Thanks. 

Its worth putting some red Loctite on the insert, it will stop it coming out in the future.

(but don’t put the bolt in until its set)