almost the same naman ang pag check sa diesel and gas engine. it should start easily (one click) after the heater lamp goes out. warm up the engine. wait until it reaches operating temp. maki pag kuwentuhan ka muna sa seller or inspect mo other part/interior ng vehicle wait waiting. open oil filler cap and or pull out dip stick. see if any puffs of smoke comes out from it. kung kaunti lang puede pa yan. worse pag oil na lumalabas sa dipstick or sa filler cap blowby na yun. pero minsan talansik lang yun from the tappets. check for oil leaks. normally pag sa harap mga seals ng pulley yun. if pawis lang ok pa yun. check mo hose going to the alternator .