Jim Grant's Tech Tips
‘02 Toyota Corolla CE, High Volume Oil Consumption
What is the cause of engine oil consumption in a ‘02 Toyota CE with only 30,000 miles. The amount is significant, 3 or more quarts in 350 miles of highway driving. There is no evidence of leaking; there is no evidence of smoke; there is heavy black soot in the tailpipe and some of it deposited on the back end of the car just above the tailpipe. The PCV valve and the engine compression checked good. The oil and filter and air filter were replaced, and the plugs were changed as well, before a 350 mile trip was made. This, I must tell you, is a second hand auction car purchased from a local dealer for $9,000. Since I didn't get it back to him before his 90 day warranty ran out, I must take the full responsibility for whatever repair may be required. The seller told me that the oil consumption was because I was using 10W-30, not 5w-30, and cheap filters from Walmart, I was in disbelief. Please correct me if I'm wrong. When I told him that the soot in the exhaust pipe and on the back of the car indicated to me that the oil was not being burned during combustion and that's why there's no significant smoke. He said that all cars have black soot in the tailpipes. This is not true. Certainly I’m no expert, but I'm no dummy, either. I'm taking the car to a good mechanic that has been helpful for well over 10 years. He'll be the one to repair it if that's what we decide. My humble opinion is that it may be one or more exhaust valve seals that may have even been defective from day one. Does that sound plausible?
If you check you Owner’s Manual you’ll find that 10w-30 motor oil as long as it has a SJ Energy Conserving or ISLAC Multigrade rating is allowable for use in your vehicle if it is operated in an ambient temperature above 0 Fahrenheit or -18 Celsius. Yet, 5w-30 is the recommended all around oil to use. The use of 10w–30 with the correct ratings will not void a warranty according to Toyota. The last time I walked in to Walmart they were selling brand name oil filters for less then I could by them from my vendor. If the oil filter meets or exceeds the vehicle manufacturer’s requirements it does not void the warranty even if you only paid 20 cents for the filter. From the day a vehicle is made, as long as you use a motor oil and filters that meets or exceeds the manufacturer’s recommendation the use of that product will not void the warranty with proper documentation. As for your Toyota’s engine, it’s bad. A quart about every 100 miles is a sure sign of internal problems. If the valve seals were that bad you would be blowing out a smoke screen every time you started that engine. I’ll bet coffee that the there is an oil control ring (likely more than one) that has failed big time. Either way the engine is coming apart to correct oil consumption problems of such magnitude.