Use of oil

My daughter has a '01 Toyota Corolla, and it “uses” 4-5 quarts of oil between the scheduled 5000 mile oil changes. No oil leaked under the car, does not burn any oil we can detect, (no blue/white smoke from the exhaust while running, and no large volume of smoke upon starting), and no oil can be seen on the outside of the engine. This has been going on for two years/20,000 miles. I have been checking in the middle of the night for tiny Arabs siphoning oil through the dip stick tube, nothing spotted to date. Car has 80,000 miles total. The only bad driving pattern she has is 40 mph in parking lots… Help.

If it’s not leaking, it’s burning. But the amount is small enough so that the catalytic converter can digest it, at least for the time being.

Check the PCV valve and hoses.

Sure there isnt a good bit of even higher speed driving going on here. If she will do 40 in a parking lot then----on the interstate. This will use oil.

That is your answer…trust me: she is driving the car too fast. I work on government fleet vehicles and that is how I catch drivers speeding: the consumption of things like gas and oil. Some drivers even go as far as spending their own money to put gas back in the vehicle because they know I am going to check mileage. A couple of things that can not be easily manipulated are tires and oil consumption. Any motor that has been broken in will burn oil in the cylinders because the oil has to aide the cooling system in cooling the motor and burning off oil is how the oil helps disperse heat from the most inner vitals of the engine. Tires will show “Speed ware” when they become cupped even though the tires are well maintained. I’m pretty sure that when your daughter turns off the engine after her normal useage you will be able to hear the hot oil dripping down into the oil pan and then you can hear that spitting-on-the-coals sound. But lets give her the benefit of a doubt. Are you also going through an abnormal amount of radiator coolant? If so, then that is the reason for oil useage because no matter how she drives the coolant isn’t working as it should and the oil has to aide in cooling. Make sure the fan motor is coming on when it should and staying on as long as it should. If all else fails tell your daughter to pay for her own oil. I had a similar problem concerning gas with my Son. He now pays for all his gas completely by himself.

Beefy Norm may be right in his suspicion of speeding. A few years ago my V8 Caprice was stolen by some joy riders. This car with 150,000 miles on it normally consumed 1 qt every 2-3000 miles. When the police found the car a week later , it was down more than 2 qts, and the interior was filthy.

My mechanic checked out the car for leaks or engine damage (none found), and told me the kids had been speeding to get the oil down so far!