Stripped spark plug thread

[cliopete]

Just replaced my spark plugs and leads to cure a slight misfire. When tightening one of the plugs it seemed to turn rather more than it should have and I think it is about to strip :twisted: Has anybody had a head helicoiled in situ or is it a full strip down job. I fear the worst :twisted:
Pete

[Rich]

can be done in situ afaik

[Lunner]

Can be done in situ, hard to find someone willing and able to do it though

[number1]

uh oh!! you do know about the half turn from finger tight then back off loose, then do them up finger tight, then quarter turn tighter? it squeezes the washer up on the plug i presume to make a good seal, have always done it, but if you keep tightening it can feel like the plug is gonna strip as the washer is compressing...

Dave

[cliopete]

I am fairly certain the thread has stripped but refitted the new plug with a liberal dose of thread locking compound and retightened it finger tight and it seems to be OK at the moment. Dribbled a bit of oil down the outside of the plug and no leaks were apparent but need to find somewhere to do a helicoil ASAP Prob try Mini Sport, they seem to have extensive engineering facilities.

[drsmith1979]

you can do it yourself if you have the right tools, helicoils are pretty cheap too, did one on my bmw with a friend, tapped out the old threads, made it slightly larger and then got the appropriate sized helicoil and worked it in..... the only issue would be small metal filings being dropped into the cylinder.. may cause damage on the pistons etc..