When an engine "burns oil" it could be caused by a number of things such as; leaking valve seats, blow-by the piston rings, and possible valve cover or oil pan gaskets are faulty. If it smokes when you run it there is a problem internally, but if you have residual oil on the motor or underneath chances are that you may just need your gaskets replaced. Keep in mind there is one major seal the "rear main seal" the motor typically has to be removed for this replacement.
There are a few reasons why engines burn oil, most of which are not inexpensive to repair.
I would have the car checked out be a certified mechanic before purchasing the vehicle to see if it is something small (like valve cover gaskets)
or if it is something large like a bad rings which requires rebuilding the engine.
Definitely have it checked out before deciding to purchase it though.
Hope that helps!
180 Degrees Automotive
〉 Answered on May 30th, 2009 by Bogi Lateiner, Owner and Technician at 180 Degrees Automotive
The term "burning oil" is what the car guys use to describe when the engine uses more oil than typical. Usually, when this happens you may see blue oil smoke out the tail pipe. It is not uncommon for the North Star engine to use a quart of oil per 1200 miles and not see any smoke. If it is using more than that or smoking, you could have a valve seal issue. Its difficult to tell for sure with out taking a look at it. If you are really interested I would ask a local dealership what they would charge to check it for you and ok that with the owner then you will know what you are dealing with and how much you should offer for it. Good luck!
〉 Answered on May 30th, 2009 by Karen Davis, Service Manager at Smith Stokes
This most likely means that the rings around the pistons are worn and oil is dripping into the cylinders. This creates excess smoke out of the exhaust - therefore the vehicle may not pass emission tests in some states. This will be more of a labor intensive job to correct the problem. You may want to make some phone calls to get some quotes as to how much it will cost to correct the problem.
〉 Answered on May 30th, 2009 by Suzanne Grego, Technician at City of Philadelphia Fleet Management