Throttle body thread repair

[Caperix]

The m20 in my e30 had both coolant lines to the throttle body plugged when I bought it. I was replacing the water pump & thermostat today & was going to replace the gasket for the throttle body heater & reattach the hoses. The threads will not take torque so I end up with a coolant leak. I tried tapping the m4 threads to a m5 but the threads pull out when tightening. There is not a lot of room for a thread insert or a helicoil, has anyone tried any thread repairs with good results or should I just look into removing the throttle body heater? I can't imagine just plugging the hoses is the best solution.

[Conrad311]

Occasionally I can get away with using a length of copper wire (or in that case a few tiny strands twisted up) stuck in the hole and run the screw in along the wire. Threads bite the copper and compression holds it in place. Those screws suck. Best bet is to leave it bypassed.