Hey Guys, I have a story and question(s) regarding events over the last week with our kx-s 2007. info: 104,000kms, havent had it long, 12 months - less than 10k kms so far with us.... on a recent drive it blew blue smoke for about 30 seconds - and having a relatively good mechanical background i knew this potentially wasnt going to be good - rings, valve stem seals, etc...so it was nursed home and garaged....no oil light or alert on dash, or noise from engine.....no prior issues at all... Next day (as it was late) I put in a flush, changed oil, filter and air filter.....oil was black so not great I know. started it again and less blue smoke but was still there...... added another flush and changed oil and filter again after about 10kms...oil relatively clean...but had only done 10kms!... no doubt it has missed a few scheduled oil changes....also changed the pcv valve for good measure started it again with a puff of smoke then it pettered out to nothing.....thinking valve stem seals at this stage and maybe not rings......took off the forward rocker cover to inspect. pretty good under there, some very minor pasty sludge / oil but nothing solid which pleasing.....cleaned it up and replaced the cover. then with new oil and filter in it, it was started again. puff of smoke then nothing (strted as blue then went almost a grey smokey colour). oil from dip stick nice and clean. took it for a 20km drive, no smoke and oil appears good. Next day, started it, puff of smoke then nothing......driven about 20kms today and no noticable smoke when driving... question is: have i just avoided a major repair bill by catching a potential sludge problem in the nic of time? i am thinking it could be valve stems seals as well, or even residul sludge accumulating in the block when stopped and being burnt when it starts.....maybe another flush will fix it further??.....doesnt appear to use any oil..... I know there are all sorts of horror stories of sludge build up in these engines and catastrophic failures, but i couldnt see anything major with the cover off....I also want to avoid being told it is a full rebuilt or changeover when it my not be the case..... any commments, thoughts or things to investigate would be apprecited.....lesson learnt - oil change straight after purchasing a car - no matter what the history is!! aside from this it is a well looked after family car and isnt worked hard at all.... thanks guys Steve