recently brought a defender, it starts and runs really well, but smokes alot mostly pulling away, driving at 60-70 theres no smoke. first i thought it was a injector / pump problem, ive checked the pump timing which is spot on, renewed air filter, losened off each injector pipe in turn to see if smoking stops which it doesnt, today i noticed water level had dropped by about 20mm on a 40 mile run. the smoke doesnt seem to smell much and is white/grey. what should i check next , thanks in advance for any replies