Heavy Oil Loss - Corolland: the Toyota Corolla Forums

Guest Clifford

My wife's 98 Corolla has 125,00 miles on it. We change oil at 3,000 mile intervals, and have never had any problems with it before.

Two oil changes back, the technician noted that the car came in with less than a quart in the pan, but I didn't hear about it at the time as I was out of town. 2,000 miles later I checked the oil and found it was already two quarts low again.

There isn't any sign of leaking, and the car does not smoke, but it is using oil at the rate of a quart every thousand miles now. I pulled the plugs and they looked absolutely perfect.I looked at the tailpipe and don't see anything unusual there either. With the engine running, removing the cap on the top of the motor shows no sign of back pressure.

If this engine is burning oil, it sure runs fine, and we still get 36mpg. I have noticed that it uses oil faster when we make a trip than around town.

Any clues, or am I just in for a big rebuild soon?

Guest Clifford

As a new visitor to this website, I posted this before I noticed the "Sludge" topic...

Holy smokes, the 98 was mentioned as a heavy oil consumer right there!

Now, can someone explain why the plugs are so clean? And,if it's the rings, can the catalytic converter really consume all of that blue smoke, so that you don't ever see it?

I am still very curious about where all of the oil is going to!

Generally a car using anything less than a quart every 3000 miles is pretty good. Also depends on the car - some use less - others much more. Someone I new had a '79 MG - used about a quart every 500 miles - which was about average for those machines.

You could be pulling oil past the due to worn or broken piston rings, worn valve guides, worn valve guide seals, or a possibly cracked / damaged piston, or a faulty PCV valve or other emissions related hardware. Could also be a leaky seal or gasket causing all the problems. Usually a good idea to just replace the valve cover or oil pan gaskets and replace crankshaft end seals - if they are the culprit.

Unless your engine is consuming oil at the rate of a quart every 500 miles or less - the usual symptoms of fouled plugs, blue exhaust, etc. may not show up or would be harder to spot. Converter probably is not hiding the smoke - but the oil may be plating the inside of your exhaust system - so very little may be making its way back to the tailpipe.

I'd be saving for a rebuild - sounds pretty grim, if it is not a gasket or something simple. Can always do a compression test to see what they look like and go from there.

Good Luck.

If you were down to one quart of oil in your pan, you may have put some wear on the engine around that time. That one quart of oil had to cool and lubricate the engine, as well as retain and suspend all the particulate matter built up since the last oil change. Needless to say, it was overworked.

'Hard to tell why it got to that point in the first place, but you may want to rule out the easy stuff. As Fishexpo mentioned, it could be your PCV valve. You can take it off and check to see if it's working right (blow through it - it should be hard to blow in, but easy to blow out) or just replace it.

And if you're burning that much oil, I suggest that you switch to a 5W40 or 10W40 "High mileage" or Max Life" type motor oil. The heavier oil will reduce blow-by, therefore lessen your oil consumption and improve compression (****uming that worn rings is the problem). The beefy additiive package that these high mileage oils use will swell your engine seals and lessen the amount you may be leaking.