Radiator has a small water leak, did a full service 3 weeks ago, there was no signs of any headgasket issues, but when I checked the oil level this morning, I found mayo on the oil cap. I've done a complete headgasket overall on the engine in August 2015 and cannot believe this is now happening again. Sparkplug no.3 is also backfiring and I cannot explain it as I replaced the whole set of boggy cords and the unit onto side as well as the water pump and the cambelt.