Just had two glow plug cavities helicoiled on a '99 W210 turbodiesel. Glow plugs were stuck because of carbon build-up, and were summarily drilled-out......

Is this an acceptable, permanent, long-term, viable fix or repair? The car seems to be running perfectly in the 50 miles or so, being driven daily since the helicoiling installs.

Will it ever compromise the seal of the cavity to the atmosphere, i.e. loss of compression, or shoot the glow plug out / malfunction?

I'm skeptical as to the feasibility aspect of anything approaching long-term (years/10s of thousands of miles) on a helicoil in the glow plug cavity.

Any actual, experience in this arena greatly appreciated!