Spark plug hard to get in

[thejinx]

Ok. Did a service the other day new coil HT leads and plugs. All went well but one plug was really tight going in. It was the same last year when I did it for the first time. I know the options are helicoil or new cylinder head. any other tricks to solve this when I service next year. Cheers

 

[rlepecha]

Before any repair methods I would try chasing the threads with an M12x1.25 tap. (Might need to double check the size!)

Doesn't sound like the thread is gone because you would struggle to tighten the plug sufficiently, or it would blow out due to cylinder pressure.

 

[Guest]

stupid question but was sh completely cold before you were making the change?

 

[thejinx]

Yes, stone cold. I've changed the plugs twice. Both times, no2 hard to get in. I take it if I use the tap I would need to pull and strip the engine? Doing in in place would chuck shavings and crud into the piston?

 

[K@rlos]

Yes, stone cold. I've changed the plugs twice. Both times, no2 hard to get in. I take it if I use the tap I would need to pull and strip the engine? Doing in in place would chuck shavings and crud into the piston?

Dip the tap in thick grease to catch the swarf

 

[ozziedog]

Before you do anything like a tap , might be good to have a real good close inspection of what`s what in the head by shoving your phone in there and taking a squillion and a half pictures. You can then blow them up a bit and see exactly what you are dealing with. I would not attempt to re tap a thread in an awkward position such as this unless I was really experienced with taps and actually doing it and not just thinking and talking about it, if it`s in your first half a dozen times of using a tap then I wouldn`t expect it to go well, sorry for the pessimism . There is a reason this plug is giving you issues or problems and that`s maybe because it`s just a little awkward to get to. Taps is rock hard and heads is soft soft soft :shock: Options if not experienced are, get some one with a ramp and lots of experience as that may be cheaper than trashing a head, or drag the lump out and do it nice and carefully on a bench where you can check how square you are. Or leave as is and make a note to give it a good seeing to when the lump is out next time and you`re on a bench with it

Ozziedog,,,,,,,,,,,,,,, Just squeeze it back in for now maybe :mrgreen: :mrgreen:

 

[thejinx]

Yes. Been on the phone to a mate. Decided to leave it as is for this summer pull the engine next winter and do all the jobs on it I should have done when I bought the van. When I first bought it I changed rings and scrapers and put it back together. I tend to pull it clean it paint it and sort all niggles. Cheers for replies all.