Did a service on a mates 2002 ZX636 today. Everything went well until we put the last plug in , NGK CR9E. My mate is new to this, so he was screwing em in until the washer touched the head, tightening until the washer was crushed and then a slight nip up. He did not overtighten the previous 3 plugs. As he nipped it up, the spanner hit the frame??? He gently undid it and I retightened it. It went tighter and then went slack. I undid it all the way and then , oh my god!! Old plug that came out New plug.Came out eventually without removing cylinder head. Neither of us is cack handed and at no time was the plug overtightened. I read somewhere that this has happened to a few people recently. Either NGK have made a bad batch or they are crappy copies, bought frrom a reputable motor factors. BEWARE!!!
Never happened to me but I've removed one for a customer from his CR450F It's a common problem I think mate, they don't make em like they used to was.... https://www.google.co.uk/search?q=s...j80QXOyoCwBA&ved=0CAkQ_AUoAQ&biw=1024&bih=672
No Colin.I butchered an old file. Used the square end taper to engage on the inside of the thread, ground four flats on the other end, cut it to length, tapped it into the thread and undid it very slowly with a 10mm spanner. Had visions of tilting the motor to gain access or even removing the head!!!
this is definately a not a new thing i have seen this years ago when i worked for a nissan dealer , young lad went to change plugs on Nissan Silvia turbo and this happened he was not as lucky as you and the cylinder head had to come off
Ngk plugs were always the best plugs on the car market.Never had confidence with any other spark plug or lambda sensor manufacturer myself.Never forget asking the then sales director why Ngk's were the best.He showed me the differences between them all.His name was John Childs who is now the boss at Ngk UK .I have sold only Ngk plugs to this very day.Shocked to hear the quality has gone down.
had that happen to me on a RGV once. I remember an old NSR I had, it used to strip the threads in the head really easy, spark plug changing was nice and tricky.
Get it loads with plugs in cars especially when they not changed or over torqued, Alloy to steel after time likes to stay together
