Loosing oil every 300 miles

oil

#1

I have a 95 Saturn SC2 with 177K miles. Every 300 miles I have to add a quart of oil to the car. The car does not smoke and the acard does not leave any oil spot on the driveway.


#2

Even if you do not see smoke from the exhaust, it is still possible/likely that the engine is burning oil at this point. There is also the possibility that you may have a bad head gasket, and that could also account for the engine losing oil. Have you checked the coolant for the presence of oil? Have you checked the oil for the presence of coolant?

There is also the possibility that there is an oil leak that only occurs when the oil pressure rises as you drive, and that could account for the lack of an oil spot on the driveway. (By the way, what is an “acard”? I don’t understand that reference.)

I would suggest that you check your oil at least every two days, as this rate of oil consumption could suddenly increase, and that could leave you without sufficient oil to keep the engine from being fried. And, if you plan on keeping this car, you really do have to explore the possibilities that I mentioned above, and then decide if the age and the odometer mileage of the car would make it worthwhile to spend a probably significant amount of money to repair it.

One thing for sure–the problem is not going to get better, and it is likely to get worse over time. If you think that you want to repair it, the cost is likely to be less if you do it sooner, rather than later.


#3

Ah geez, there’s something wrong big-time. You could still be burning oil and not see smoke, as the catalytic converter would catch it (if that’s the case, at this rate the converter will be toast soon). Burning a quart every 300 miles points to severely worn oil control rings or nonexistent valve seals, or both. Did this car have regular maintenance done to it over its lifetime?


#4

Budd makes a very good point. The likely oil burning will cause a quick death for the catalytic converter. As I said previously, if you intend to keep this car, you need to take action on repairing it very soon, before the repair bill exceeds the book value of the car.


#5

If your oil is mixing with coolant, the oil should be a milky brown; a bit like a chocolate milk shake. Pull your oil dip stick and see if it looks like oil or a milk shake. If it’s a milk shake, you need a new head gasket. If not, it may be blow by in the valves or the cylinders. Valve leakage means a top end rebuild; cylinder blow by means an engine rebuild. You could have a vacuum test run on each cylinder to tell you if the cylinders hold pressure well. If so, it’s the valves.


#6

As I recall those Saturns from that time had problems with burning oil. As others have noted, you may be burning it and not see smoke, but you likely will need a new converter soon. GM liked to use the “That’s Normal” argument.

In addition to the suggestions already noted, I might suggest a compression test. It may also prove interesting.

Good Luck


#7

All excellent posts. I just wanted to clarify that even though I agree wholeheartedly that a compression test would be a good idea, it is possible to pass oil by the oil rings (burn oil) and still shop acceptable compressions. The oil rings could be shot and the compression rings still okay. Many compression rings are designed to push against the cylinder walls when combustion is happening (when there’s pressure from above the rings) and those rings would allow oil by during the intake stroke, when the pressure above the rings is lower than the crankcase pressure. Oil rings should control this if they’re good.

In addition to the headgasket checks VDC mentioned, there’s a test where the cylinders are pressurized with air and the ability to hold the pressure is checked. That’s called a pressure leakdown test, or a compression leakdown test. That can give you a definitive answer as to whether you have a bad headgasket.

Oil rings fail because of wear, because they lose their spring tension (against the cylinder walls) from all the heat and pounding, and sometimes because they get gummed up. If you have no signs of a blown headgasket, you could try a flushing product from the parts store to flush the oil system out. It might help. Follow the directions on the container exactly. It’s possible that the oil rings are gummed up, and that might help.


#8

GM Dealer has a top end engine cleaner that is used to perform a piston soak. This sometimes helps with the oil consumption, and sometimes not. Its worth a try.