How would you fix a car that burns a lot of oil?

Answer 1

The first step is to establish HOW your engine is losing oil -- whether it is actually burning oil (usually indicated by blue or black smoke) or leaking it.

A "minor" leak from a worn-out drain plug or a bad gasket can result in the loss of a surprising amount of oil. Also, oil leaking onto a hot exhaust pipe can produce the same blue or black smoke, even though the engine isn't actually burning it.

If the oil loss is relatively small (whether through leaking or burning) or if you can't immediately determine the cause, it MAY be worth trying an oil additive or "stop leak" -- typically less than $10 at an auto parts store. That's a lot cheaper than major engine work. Another "worth a try" solution is to use a heavier grade of engine oil -- for example, straight 30-weight or 20w-50 in warm weather, instead of the 5-30 or 10-30 frequently used in modern engines

Following are some typical reasons why an engine can burn oil, and the most common repairs:

--leaking or sticky internal engine components. An oil additive or "engine flush" may help by cleaning out gunk, allowing the old components to seal tightly. Another treatment widely available at auto parts stores, Sea Foam, is praised by many shade-tree mechanics.

An old-timer repair is the so-called "Italian tuneup" -- running the engine at high rpm (but below redline) for at least 20 minutes (for example, driving at freeway speeds in third gear). This helps to burn off carbon in the combustion chambers and on rings, while creating high oil and engine temperatures and vigorous circulation that can help flush out deposits. However, make sure that you have sufficient oil and engine coolant before trying this.

--leaking valve stem seals. Typically, these allow oil to drip into combustion chambers after the engine is turned off, resulting in a puff of smoke at startup but little or no other visible burning. This repair can frequently be done with the engine in place, and without removing the head.

--worn-out piston rings and/or piston oil seals. Usually, the only effective fix is to have the engine rebuilt, which will cost several thousand dollars (and is NOT a job for beginning mechanic). Buying a replacement engine from a wrecking yard may be more economical, especially if you do the installation yourself (mostly a matter of disconnecting/unbolting the old engine and then reversing the process -- but BUY A SERVICE MANUAL and take notes and photos so you remember what goes where).

Don't accept a mechanic's word that "the rings are shot" without some kind of proof. There are various ways of testing piston rings, including compression checks and cylinder leakdown tests, that can help pinpoint the cause. Most well-maintained, modern engines can go at least 150,000 miles before starting to "burn" significant amounts of oil.