Questions and Answers
Toyota Burning Oil
Q. 1991 Toyota, 80,000 babied. Started to burn oil one quart a week. Why? And, I am handy but have not rebuilt an engine in 35 years. I will replace most defective car parts, breaks, clutch, water pumps, transverse engine timing belts, but have not worked in the engine.
What is the scope of the work, I do not have a powerful torque wrench.
A. Right now the important thing is to determine the cause of the oil consumption. Is it from the valve seals or the rings? A simple wet/dry compression test will tell you this.
To do an accurate compression test, remove all the spark plugs from the engine. Then disconnect the coil wire from the distributor and connect a jumper wire from the coil wire to the negative (-) terminal of the battery. Prop the throttle plate so it is wide open. Connect a remote starter button from the positive (+) terminal of the battery to the small connector of the starter. Put the ignition key in your back pocket.
Now install the compression tester in cylinder number one and crank the engine about six or seven turns. Write down the compression reading and go on down the line. Good compression would be about 150 - 180 pounds. More important that the actual compression is that the readings should all be within 10% of each other.
Now that you have the dry readings, squirt two or three good squirts of motor oil into number one and do the test over. Note the reading next to the dry reading and go on down the line. Once you are done, compare the wet/dry readings. If the wet readings show a marked increase, say 20 to 25%, then you have ring problems and it's time for an engine overhaul. If there is a small increase, say 5 -10%, then the problem is in the valve seals and they will need to be replaced.
Additional Information provided courtesy of ALLDATA
