Can too much oil be a problem?

I recently took my Subaru Forester in for its first oil change. I pulled the dipstick today and found that the oil level is about 3/4 inches above the full mark. I can not find the oil capacity for the engine in the owner’s manual but found 4.7 on an oil companies Internet site. The statement from the dealer indicated 5 quarts were used.

I have been changing my own oil for 20 years in my 2005 Toyota. I am always careful not to overfill because I have heard it can cause aeration of the oil resulting in poor lubrication. I know 0.3 quarts of overfill does not sound like much but what do you think? I will be calling the dealer in a couple of days.

3/4 inches sounds like a lot. I’m sure you’ve measured it cold and after it sat for a while after running. I’d call the dealer’s service desk before running it very much.

You should check the receipt given to you to see if it shows how much oil was installed.

It is possible they didn’t let all of the old oil drain out or maybe they didn’t remove the old oil filter which would have oil in it. There are also conditions that will allow water to get into your crankcase oil.

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Thanks. I found the oil capacity in the manual and it is 4.7 quarts. The oil change was free but they gave me a statement that said 5 quarts were used. I’ll be calling the dealership tomorrow.

I would be interested in knowing what the dealer tells you.

The Dealer’s service representative said that the technician should have checked the oil level after the change. He asked me to bring the car in so the level could be adjusted. I will be taking it back in.

Thank you. I hope the dealership doesn’t try to get out of their responsibility.

Most, if not all, of today’s motor oil manufacturers include anti-foments in their products. A little extra oil in the sump for a few hours of operation should not cause any harm.

Back in the sixties when performance enthusiasts modified engines by increasing the stroke, they found running at high rpm’s caused lube oil foaming, and a little less oil and/or added anti-foament usually took care of the problem. On some engines additional oil sump capacity was needed to solve the problem.

Same thing has happened to me. Twice. I don’t why I take my car to the dealer for service. They’re friendly, have a nice waiting room, free snacks and drinks, free shuttle to anywhere in town, etc. But they don’t seem to employ very competent mechanics.

The time before last when I had my oil changed I didn’t check the dipstick for about a week. I found it way overfilled. Plus they hadn’t topped off the washer fluid. They never check tire pressure, either. So I brought it back, they apologized, and drained out the excess oil and filled the washer tank.

The last time I got some paper towels from the men’s room and when they announced my car was ready, I asked if they minded if I checked the oil. The service advisor came with me. The dipstick was about 1/2" over. The actual mechanic happened to be walking by and when he saw the car he scowled and said “what’s wrong?” The advisor pointed out the excess oil. He grumbled and then took the car back. When they were done the advisor said that the oil pump was off and needed to be calibrated.

All that to say that no matter what the owner’s manual says, they will put the nozzle in your engine, set it to 5 or whatever, and then it will automatically fill and shut itself off like a gas pump. If their machine is off it may be under- or over-filled. Or if they didn’t allow enough time to drain the current oil or if the engine hadn’t run long enough to get hot and thin out the oil.

I doubt there’s any damage with over-fill compared with under-fill but it’s good practice to double-check your car after getting it serviced. Another annoying thing is that they often switch off the auto headlights and I don’t notice until it’s dark and I can’t see. :slight_smile:

Just an update. I put about 50 miles on the car before taking it back to the dealer. According to the work order I was given, 1/2 quart of oil was removed. I will check the oil level before leaving at the next change.