As mentioned in the previous post, my S15 was performing like a champion at the track. Water temps stayed between 80-85°C the whole time and oil temps staying below 90°C. Couldn't have asked for a better result.
But tragedy struck after entering the pits and we lifted the bonnet... Roughly 750mL of coolant was pushed into the overflow bottle, which is very strange because the car never overheated. Even stranger was that the coolant in the overflow never sucked back into the radiator, we even left it to cool for about 60-90mins.
After some reading, testing and talking to a few workshops. We concluded that combustion gases were leaking into the cooling system when the car was on boost. This pressurised the cooling system and forced coolant passed the radiator cap and into the overflow bottle.
Initially I decided I would send it to a workshop to get my S15 repaired, but my mates Duy and Jess convinced me that I should do it myself at home (with help of course!). So below is the progress from today...