Help! Cross-threaded Spark Plug On Xu10j2 Head

[KRISKARRERA 2 1 Cars]

My dad was just changing the spark plugs on his 405 GTX (XU10J2 engine) and whoever last changed the plugs had cross-threaded one of the spark plugs - work done by a garage

What happens now?

Can it be helicoiled? And how much is this likely to cost?

[Richie-Van-GTi 71 2 Cars]

biggest expense will be head removal, if a bit of thread has gone into bores it could cause serious problems.

[KRISKARRERA 2 1 Cars]

Can't helicoiling be done with head in situ?

 

We put the new plug in and tightened it down and crossed fingers. Seems to drive ok.

[t16ryan 1]

yeah heli coil it in situ, just when fitting plugs dont do it up real tight just a nip thats all it needs

[Anthony 1,003]

If worse comes to the worse then you can helicoil it, but it you've got the plug back in and it tightened up OK then it should be fine - it's when they don't tighten and just spin round and round (or fire out when then engine's running) that they're screwed.

 

I think last time I had a sparkplug helicoiled in situ it cost me circa £30.