Help! Stripped water pump threads in block.

[Shadowhunter]

I was in the middle of doing a mini cooling service, water pump, thermo etc.
Got the old pump out put the new one in and lo and behold 3 bolts tighten up but the one on the top right does not, pull it out to find metal all over the bolt. Anyone have any ideas on what I can do to fix this? I really don't want to go the helicoil route. Does anyone know the size of the bolt hole m10X1.50? Would it be advisable to try a tap and die kit? Any help is greatly appreciated.

[Honolulu]

Chasing the threads with a tap is unlikely to help since the threads are pretty gone already.

That said, there are things you can to.

One: live without that bolt. The others may hold the WP on sufficiently. I have done this with other Bimmers. One gone is not too bad, two gone is not good but survivable if they are not adjacent to each other.

Two: tap, reinstall and see how she goes.

Three: clean the hole with brake cleaner or carb cleaner, install a stud with some JB Weld or appropriate Loctite produce, and use a nut to hold on the WP. If the bolt hole is really screwed and you won't use a helicoil, this may offer the best outcome.

[ti-billy]

Helicoil it or tap it a size up and use a different bolt. Don't funk around when it comes to your cooling system.