Spark plug hole thread repair results

[bimmerd00d]

this happened way back in my '93 525i m50tu. I had a shop repair the threads with some kit. tap/dye and sleeve or something. Helicoil maybe, i can't remember. But the head was definitely left in the car, and it was a great success. I put another 100k on the car after this and the motor ran perfect the day i sold it.

[redandgearhead]

I had the number 2 spark plug try to vacate the facilities the other day. It either backed out and then, because the plug was held in by the coil, hammered out the threads, or the threads failed.

I did a search and found a few threads (no pun intended) discussing the same problem. Helicoil or Timesert was the repair of choice.

There wasn't much discussion of the success of the repairs.

Would someone who has had this repair care to step out and tell us what was done to repair the threads and if it worked out? Was the head removed or left on the engine?

Thanks,

Joe B.

[Ross]

Agreed. You can do it yourself too. Put some heavy grease on the tap to catch most of the chips, the little bit that goes in the cylinder is soft aluminum and will get blown out the exhaust.
Always be sure to let aluminum heads cool before unscrewing the plugs.