R32 melts plugs help needed

[coljon]

My son just recently bought a "89 r32 gts 4wd Skyline witch was running fine till today. While driving the car started missing and loosing power, he removed the plugs and two of them were melted. Put in new set of plugs but now it is still missing badly, sounds like timing is out to me . Any help greatly appreciated. What causes plugs to melt? Occasionally the 4wd dash light flashes on but i dont think this would have anythink to do with it. Hard to work out with no manual.

[SteveL]

My son just recently bought a "89 r32 gts 4wd Skyline witch was running fine till today. While driving the car started missing and loosing power, he removed the plugs and two of them were melted. Put in new set of plugs but now it is still missing badly, sounds like timing is out to me . Any help greatly appreciated. What causes plugs to melt? Occasionally the 4wd dash light flashes on but i dont think this would have anythink to do with it. Hard to work out with no manual.

If the spark plug has literally melted then you could have a serious problem...stating the obvious perhaps but it means it's getting too hot. This can be caused by a number of things - incorrect plug heat range, mixture too lean, pre-ignition - but you should pull the rest of the plugs and check their condition as well. I would recommend having a compression test done to check engine condition....the fact you now have a bad miss could suggest damaged valves (eg burnt due to lean mixture). If possible have a leak-down test done in preference to a compression test, but not all mechanics have the capability.

Once you've established engine condition, you need to find out why this happened. If it's just wrong spark plugs then it's an easy fix, although could be something more serious (eg poor fuel delivery, major air leaks).....but it could also be simply that the car was over-boosted and the mixture leaned out.

Personally I wouldn't drive the car until I knew what had caused this and had it fixed.

Good Luck

[KamikazeR33]

i would have 2 say that the plugs are a wrong heat range and perhaps not gapped properly.

if its still missing one or more of the coil packs would be dead

[r32skyline_89]

check your fuel pump, it could be causing the miss if its coming on and off. And if so your engine would be running lean, which cooks the f*#ck out of your engine. Which could explain the melted plugs.

[r32skyline_89]

If not that check AFM (Air Flow Meter)

[coljon]

Thanks for help everyone, pulled head off last night, no compression in front and rear cylinders. Burnt a hole in exhaust valves. Car is running high boost 14psi I think, he is concerned because it has flat top pistons which would give it very high compression. Pistons have the no. 59S & .05 on top of them does anyone know if these are standard pistons Thanks