good morning mga pafs... i have a nissan sentra series 3 model 98,well maintained, tune up lage when its time to tune it up, over 10yrs na sa fam namin yan BNEW nung binili,pinasa lang sakin ng mother ko... yung mileage nya around 177,000km/hr na ata... after reading so many threads here about engine problem, i did some of the troubleshooting according to what other peeps said.. im not sure if i need to major overhaul my engine or just top overhaul, it started when i drove from manila to subic before i hit the road i did change oil the brand is mobil worth 1.8k,change oil & air filter,then when im on the NLEX, nagtataka ako bakit mausok, then nakita ko sakin galing yun, then nag observe ako, pag nag5th gear ako and i hit 80 - 100km/hr above ang usok ng buga ng tambutso ko, then i just ignored it because the temp on my gauge said i have normal temp then when im near the toll at clark, pag nagbreak ako biglang namamatay yung makina, and what i did is just continue my way home running at only 60-70km/hr, and nung nakarating na ako sa pupuntahan ko chineck ko yung water=normal without oil or anything on it, but nagtaka ako sa oil dip stick ko, low agad yung level ng oil ko and ang itim then parang may mga splashes ng oils hangang taas bago sa hawakan..pinacheck ko agad sa mekaniko, sabi change oil, edi nagpachange oil ako again and the mechanic check filters(air,oil) spark plug,high tension wires,belts,radiator, everything that might possibly caused this, ok naman daw lahat.. then when i hit the road back to manila, i experienced the same exact problem, but this time hindi namamatay yung makina pagnagbreak, then ive read some of the threads here, and did some troubleshooting pag may tama na yung makina, binuksan ko yung makina then tinapakan ko yung gas ng todo nilaro laro ko, wala naman usok, chineck ko yung oil ko may splashes parin sa dip,im not sure what to do here, guys help naman po... di ko po kasi kabisado sa pag troubleshooting ng makina, kung PC lang yan expert ako jan pero hirap talaga pag car na... and im afraid na baka nga over hauling gagawin kasi laking pera nun...if ever man, magkano kaya aabutin atleast estimate lang po guys.