tonymitsiv6

finally took it to mechanic and he said only use premium fuel. I had been using regular gas for a while so I changed and no further problems found! It must have been something to do with the timing being retarded automatically by the ECU and causing too much current to flow to the plugs. Unfortunately, it now has a small leak in the head gasket which shows up with a cooling water test but otherwise no problem, runs sweet. Also well past its date for a timing belt replacement. What should I do now?

the 6G72 is fitted to quite a number of cars in USA and Japan. We buy mostly used imports from Japan (I am in New Zealand). My car is a 99 Chariot Grandis Royal 7 seater. The fault showed up as a miss fire with usual hesitant running. It would be easy to mistake it for unbalanced wheels or bad plugs. I was not looking forward to removing the rear plugs as when I looked online it seemed to be an involved process. Luckily on the Grandis there is a bit of space at the back of the engine. You need a long plug socket to reach down in the head and you don't want to get it stuck down the hole! As I had a set of plugs (NGK) I set about changing them. It was then I noticed the burn through on the tube. It was easy to not notice this fault as the burn through mark was only small. I have replaced 3 so far so am getting good at it!

sure thing, but with a V6 and $140 a pop, it's tempting to get used ones. What I can't work out is how the H.T current burns through the quite thick plastic material - always in the same place.

yes, using plugs as detailed in handbook. Problem arose before fitting new plugs and seems to occur on the plastic tube that goes from the coil to the plug top. It shorts between the tube and the head. The tube is about 10cms long.

Hi, new on here. Anyone know about short circuit coilpacks and consequent missfire? I have replaced 3 so far and all show signs of electrical burn through on the rubber tube going down to the spark plug. OK I am using second hand replacements as new ones are so expensive. I can use just the tube but these are difficult to find.