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Oil Level

I have a 2002 Toyota Corolla that takes in 5W-30 oil. I change oil myself and I put in Synthetic oil. For some reason I put in 10W-30 the last time I changed oil and drove around 1000 miles when I started to hear mild sound when I let pressure off the gas pedal. When I took it to the dealer, he said the oil was very low, so they went ahead and performed an oil change (with 5W-30 I would think).



After driving about 1000 miles, I faintly heard the same sound that I had heard before so I checked oil level and it was again very low, so I went ahead and topped off the oil.



I do not see any oil leaks in my garage or the place where I park my car at work, but the oil level depletes very quickly. Now I check every few days and I noticed that after about 500 miles, the oil has gone down about a quarter from high mark on the dip stick.



By the way, the car is very clean, drives smooth as silk and has no other problem, thus far anyway. Any ideas what could be causing this oil depletion or what else I should be watching out for?

I think you have to assume that the engine has gotten to the point where it is “burning” oil. The fact that you can hear new noises coming from the engine is an indication that some damage has been done by chronically running it with a low oil level.

You should monitor the oil level very frequently, as the rate of oil burning can suddenly increase. Try not to allow the oil level fall more than 1/2 a qt. before you add oil, in order to prevent the remaining oil from being overworked.

There is also the possibility that you have a bad head gasket, and that possibility makes it doubly important that you monitor the oil level very frequently. If you observe that the oil looks “milky”, that would confirm a bad head gasket. If you believe that you have a bad head gasket, rapid repair is necessary to avoid even more engine damage.

I agree with VDCdriver and would only like to add that you might try using a “high mileage” non-synthetic 5W-30 oil. It might help you burn less oil.

How many miles are on the odometer?

I don’t thing you’re burning oil. Especially if it was all of a sudden. The car seems too new it sounds like you take care of it very well. I think something else is wrong here…Maybe a stuck PCV Valve.

Knowing how many miles are on it would be helpful.

You may have a little bit of a couple of things going on - you might be burning a little and leaking a little. There are all sorts of oil leaks you can have that never make it to dripping onto the ground, so you could be leaking without that kind of evidence. If ALL of this loss were being leaked out it would probably shop, if some leaked/some burned you might not see it on the ground. Pop the hood and look around all over the engine from the top down for signs of oil. Also crawl down to the bottom and look at the oil pan. (I currently have a vehicle with a very leaky oil pan, but it never drips when the car sits).

You should also have a good look at your coolant (radiator & reservoir) to look for evidence of oil there.

Without knowing the mileage, everything is guesswork…I have seen air-filters damaged because of rodents or a backfire and the trapped material gets sucked into the engine. You CAN go from low oil consumption to high oil consumption very quickly…

What is your actual oil consumption?? A quart every 1000 miles? That falls in the “normal” range for most cars, especially if they show over 100K miles. You might have better luck with 10/40 mineral oil, “high mileage formula”…But before you panic, check your air cleaner and its housing. Find any oil in THERE??