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Q: Suddenly disappearing motor oil found in coolant reservoir. on 1995 Buick Regal

My 95 Buick suddenly started using oil. Oil is appearing in my coolant reservoir. This car has never lost oil before, car has had no signs of any issues until the check oil light came on two days ago. I forgot to tell Hubby about this. Yesterday a friend checked the oil level for me when the light came on and stayed on after a miles drive. He added almost a quart of oil. Today it is a quart low.

I have driven approximately 50 miles since noticing the light two days ago. The car has never overheated although the temp gauge went up to half way while sitting in construction traffic in 90+° weather for about 10 minutes a month ago.

Two months ago hubby had oil changed at a local station. They did not use a hoist and used oil from a drum. When hubby asked them about the oil brand all they said was it was a quality Canadian oil. Up until this oil change, hubby has maintained the car since we purchased it 4 years ago. The car had been excellently maintained and came from friends. When we bought it, the car had 95K miles, it recently turned over at 120K.

This car has performed well, runs like a top, as the old saying goes. There has been no leaking other than the standard AC leakage. The oil level never dropped between changes.

Research mentions an intake manifold gasket, blown head gasket. The oil light never came on until two days ago. The car has not displayed any symptoms of a intake manifold gasket leak. The gas mileage has been great, the car performs as well as it did the day we bought it.

There is no foaming under the radiator cap.

Do you have any ideas of what the problem may be?

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Your engine may have a oil cooler which would be located between the engine block and the oil filer. If so equipped it may have developed and internal leak. Pressure testing the cooling system would be the first step in trying to determine the cause of this problem.
My hubby is taking the car to a local, long established garage. They said they will check it out to see what the issue is. A 3.8 doesn't seem to have such a good record even if the car has had very good care. I will post when we have an idea of possible issues. Keep your fingers crossed for us. Living on limited incomes, especially in today's economy is difficult enough without factoring in a costly repair bill.

He is back. The suggestion was, because the mechanic doesn't think it is the head gasket, so he recommended washing out the reservoir, replacing the PCV valve with a brand name, changing out the oil, filter, then topping off the anti-freeze, driving it and if oil appears in the reservoir again.

I will be back. :-)
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