Probably not. Engines that burn oil that is getting past the rings will often have very good compression and engines with low compression might run just fine and not use any oil. That test really won't help in this situation. What you could try, if you can find the equipment, is a cylinder leakage test. With this test you are looking for the CAUSE of low compression that you have already measured but in some instances it will work for oil burning too. You can buy the equipment from the guys in the tool trucks like MAC, Matco, Cornwell, and Snapon, and you might be able to rent or borrow it from one of the auto parts stores. A lot of them are borrowing tools now for free with just a security deposit.
The test starts with removing the spark plugs and testing one cylinder at a time. You bring the piston to top dead center on the compression stroke. There is a hose you can screw in with a whistle on the end. When it stops whistling, the piston is near TDC. Then you use the timing mark to set it perfectly on TDC. The tester has a hose that is screwed into the spark plug hole and another one that is hooked to compressed air. The gauge on the tester will show the percentage of air leaking out of the cylinder. Less than 10 percent is good. The engine should be warm when doing this test. While the air is blowing into the cylinder, you listen in four places to see where it is coming out. That will identify the cause. Tail pipe means a leaking exhaust valve. Throttle body means intake valve. Radiator bubbles means head gasket or cracked head. And the oil fill cap or dipstick tube means piston rings.
It is very uncommon but a crack in the head could allow draining oil to seep into one of the runners for an intake or exhaust valve. If it is leaking into an intake valve, you might find a clue by starting the engine cold, then shut it off before the smoking stops and pull out the spark plugs to see if one is wet with oil. If they're all dry, that won't be conclusive, but if you find one that is covered with oil, that's where to look closer. You probably won't hear the leakage from a crack in the head because it will be much smaller than the leakage past the piston rings. Instead, remove the valve cover and look for signs of bubbling in the head casting.
I've also heard of people doing a full engine test but it's fairly involved and might not work as expected. This involves sealing the air intake, typically at the throttle body, sealing the tail pipe, and blocking the PCV hose, then you connect the hose from the tester to one of the vacuum ports on the intake manifold. This is supposed to allow you to look for bubbles or hissing at the valve guides and seals.
Another approach might be to use a "smoke machine" to inject non-toxic smoke into each spark plug hole, then watch for signs of it coming out someplace where there is normally oil. These smoke machines connect to the car battery for power and put out white smoke at 2 psi. They come with a lot of adapters but you might have to rig something up to fit a spark plug hole.
Wednesday, December 1st, 2010 AT 5:19 PM