How can I tell if my 1983 240D 4 speed needs new valve seals ($450) or the complete valve job which will be many, many more dollars? Miles are 139K, and I am burning 1 qt of oil every 463 miles, calculated in my pda every fill-up (sidenote getting 26-27 mpg each tank). Any suggestions or tests I can have done to pin down the culprit and solution to the big clouds behind my car? I have to say, every car behind me on the road seems to move into other lanes very quickly!!

Thanks,

Tim