Cracked Head/coils/plug ?

[nakuma]

Hi guys,

After a few days of not running my car at all the radiator ran half dry.

Not realising this I took her out for a spin only to notice about 10 minutes in that she was making a quick popping sound under full load and I noticed the engine light flashed (power fc knock warning). I quickly pulled out the powerfc hand controller to realise it was running 120 degrees and limped her home.

My problem is, after searching the forum and google and filling the radiator back up; I'm not sure what the problem is now. It's still misfiring under full load only up in the high rpm which is causing the loss of high end power in that range. It's still knocking a lot higher than normal under the same conditions. But, that's all... No smoke, water temp is fine again.

Coil packs? Or the dreaded cracked head gasket?

I've got the car booked in for a look at RE Customs on Wednesday, but I'd like to know what is going on before I'm surprised with a possible head gasket replacement.

I've checked the oil cap, dip stick for a milky look of the oil and radiator for surging water or oil in the water. One thing I did notice though, the water in the radiator seemed to be frothy after 5 minutes while warming up, then ok again after a test drive. I've attached a few pictures so show you what I mean.

Any help at all will be appreciated.

[nakuma]

No one has seen this before?

I'm really hoping it's just air in the cooling system...

[TRB-001]

yeah going off wot your saying i dont think it will be the headgasket..... usually the head gasket wont cause a miss like that unless its overheating at that time (which u have said u fixed but it still misses)....

the bubbles in the coolant is normal if the engine was hot,running and u were topping it up, and if they have gone away then again i dont think itl be headgasket....

the miss is probably the normal coilpack problem our skylines have.

that pic of the dipstick looks fine.... tho saying that if the headgasket was leaking it wouldnt show up straight away, it takes alittle while for the water to turn to that milky colour.

[mad082]

you can also have a headgasket go and not end up with water in the oil (or vice versa). i had it happen on a falcon.

[nakuma]

took the car into re customs today

turns out the spark plugs were giving up

$100 later she is perfect again

thanks for your help guys