1999 Corolla burns oil...

Do a visual inspection of the engine for any leakage, paying close attention to areas above the exhaust system. Remove and inspect all the spark plugs, looking for any indication of oil fouling. Do you notice any leakage visible on the ground when the engine is running at idle and increased rpm? Those are a few easy and cost effective first steps. The overfilling mistake probably would not have done any harm for causing oil consumption to occur now IMHO.

Interesting and you continue to throw expensive oil at it? Why not switch to a cheap, multi weight conventional motor oil, at least until you find out where it's leaking and get the gasket/seal replaced.

I would bet that you have a gasket or seal leaking and if your luck is like mine, it's going to be a rear main seal, not something easy to get to like a valve cover gasket.

Over filling the crank case can cause seals to start leaking due to over pressures. It can also cause the crank case (oil pan) gasket to start leaking.

Look around under the car after it sits in one place over night. If you have a leak, that should show where it is located on the engine.

Well, when you guys figure this one out, let *ME* know, cause my '89 Mazda is doing the SAME THING! I *did* overfill the CC once to get the hydraulic lifters to 'recharge' and it worked, but I filled it with Syntec and MMO, about 1/2 quart over. and also, no sopts where the car is parked, and no oil underneath the car!

But it could be flinging the oil all over the bottom of the car, not dripping when parked, leaking on the exaust if you actually smelled burnt oil or any number of things. If you turn off the engine and take a look at the time you smell the burnt oil it may shed some light.

Most engines make some pretty nasty noises after sitting that long when first started. Espessially if you have the hood open.

Even though your "mechanic did a tune up and didn't see any problems with the car." I am sure he will do any work work you want (needed or not) to keep his customer happy. But if your car runs fine and just uses a little oil then there is no problem. If it's consuming the oil it is not likely to get worse for a very long time.

For example my C&C truck with a 22RE at 60,000 miles burned a quart of oil every 200 miles. Now it has almost 200,000 miles on it and still burns the same amount of oil. It has never had any oil related problems and even passes the California smog tests.

The truck is a unusuall example though. I've always assumed that most of the oil burned is due to how hard the engine has to work. When I am stopped at a red light or going down hill on the highway are about the only time it is ever less than full throttle.

Dan

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Damn, man, Full Bore on *everything*!?

When you say a couple of quarts every few thousand miles, are you implying that the engine is using less than 1 quart every 1000 miles? If so, I'd quit worrying. Of course you should do the basics like make sure there is not a major leak and replace the PCV valve. However, if the car is not leaking oil, there is no visible smoke, and you are using less than 1 quart per thousand miles, there is nothing you can do that won't be more expensive than just adding oil as needed. For a car with that many miles that is using oil, I'd quit using Mobil 1 and switch to one of the extended life motor oils instead. If the high price of synthetic doesn't bother you, you could always you the high mileage version of Mobil 1.

If there is not an external leak, there are only 4 places the oil can go - 1) past the rings, 2) past the valve guide seals, 3) through the pcv system into the intake, 4) into the cooling system. 1, 2, and 3 won't have any external symptom if you are less than a quart every

1,000 miles (and probably not until you are well over a quart every 5000 miles). 4 would show up as oil in the coolant. You should make sure the pcv valve has been replaced and that the lines are open - this should eliminate 3. If you have leaky valve guides / seals (2) you could would have to have the head removed and refurbished - not a cheap job. If the oil is leaking past the rings (1), well that means a rebuilt engine.

One thing to remember - all piston engines by their nature consume some oil. Engines that appear to use no oil, are just making up the loss with blow-by products. So even engines that appear to use no oil because the oil level doesn't change, might actually be using a lot of oil but just making off the difference because of excessive blow-by.

Replace the PCV Valve, check for leaks and if none are found, just drive is my recommendation - just be sure to keep a check on the oil level!

Ed

The blow-by explanation is impressive, but blew by my brain.