i have a 98 f150 ,4.2 v6 i bought it a month ago. it has a jasper motor was installed when the truck had 80,000 miles it has 120,000 now. check engine light is on. i took it to the dealer and got the oil changed, and they said everything checked out. last sunday the coolant level was about 1 and a half inch low, so i topped it off, i checked it today, and it has dropped 1 inch, and i put about 400 miles on it in 5 days. so now i am worried, you guys out there have any ideas? and i have not smelled coolant, or seen a leak. thanks, jim