I have an odd problem with my 90 Jetta 8V 1.8l. At times it smokes bad, more at stop lights it seems but then most of the times it doesn't smoke bad at all. Very little in fact. Doesn't seem to make any difference if's it hot or cold. It also uses a quart of oil every tank full of gas, (350 miles). It has NO oil leaks and will not foul any plugs. Changed them at 30,000 miles and all were nice and clean. Car has 156,000 miles on it and runs pretty good. One thing is that the OxSenesr went out and at the current time it is unhooked but has smoked ever since I have had it, about two years. When I got the car (for only $150.00 from a friend of a friend) it set in my carport for about a year before I put it on the road. I once had a Chevy truck with a 350 in it and it used allot of oil but also fouled plugs all the time. How can the Jetta go through so much oil and not foul plugs?