2012 Subaru Outback overfilled oil

subaru
outback

#1

My dealer changed the oil and overfilled it by over a quart. After driving 5000 miles they drained 6 quarts out and it’s supposed to hold 5.1 qts according to the service department. Do I need to worry about my engine??!!!:confounded:


#2

What did the dipstick read when you checked oil level between changes?

Normally, 1 qt over isn’t a big deal. But since it appears you haven’t been periodically checking oil level, who kniws how much it was overfilled 5000 miles back. You would spot this and other issues before they cause damage if you develop habit of periodically checking oil level. Trust but verify…


#3

Great advice for the future. Apparently I have been trusting but not verifying. I have no idea how much oil the engine uses over the course of 5000 miles. I was getting close to an oil change and checked it and it was over. So surprised. You’d think the dealer would know how much they put in. I was just wondering what possible repercussions this could have on the engine and when you’re likely to see it if there was damage.

Thanks for your input.


#4

If it has not caused an issue no worries. An old trucker bud of mine has service done and pours an extra quart of oil into all of his and his kids cars. He never had a problem because of it. Now your worry could be how did extra fluid end up in the oil, as throwing away profit on extra oil is not something I have experienced in an oil change.


#5

I don’t think you have a problem. On the rare occasion that I have someone else change my oil, I always check it before I leave the lot. Mainly looking for no oil.


#6

many subaru dealers do this. Happened to me several times. Stated reason: to compensate for possibly burning oil (which is silly, but it’s from a service writer).


#7

If sufficiently overfilled several unpleasant things can happen: the crank strikes the oil whipping it into foam which the oil pump can’t properly deliver resulting in oil starvation and damaged bearings (so one can, so to speak, be over filled and suffer from low oil). Excess oil can enter the crank case vapor ventilation system passing through the intake manifold to the combustion chamber resulting in excess oil burning which can cause problems with engine deposits and shorten the catalytic converter life. In sufficient time the crankcase ventilation system can plug causing excess pressure in the engine that can damage seals. I haven’t seen problems with a half-quart over but for more than that I’d have the shop remove the excess, either by sucking it out the dip stick or through the drain plug. Those who drive on steep grades may encounter problems sooner.

It’s possible for the oil level to start out proper but increase over time due to dilution by fuel getting past the rings (possibly due to excessive short trip driving) or, worse, coolant leaking into the crankcase which is identifiable by the oil appearing on the dipstick as a frothy, opaque milkshake or mousse. The former is not good and the latter quickly becomes catastrophic.

As others have recommended, it’s good practice to check oil level before driving away from a change and regularly thereafter, perhaps every 1 or a few gas stops. Excess oil consumption can develop quickly, catching one by surprise.


#8

The problem with checking oil, at least for my model, is that the dipstick cannot be read accurately. within 1 quart at best. So if it reads about one qt high, I let it ride.

Has something to do with the curve the dipstick has to make due to the opposed 4 configuration. the oil level line on the dipstick is just a streaky blur that covers about 1/2 inch, perhaps an inch.


#9

The dipstick design really is terrible. But with patience I have been able to get a consistent accurate reading.


#10

Finally the voice of reason here. It’s scary to realize the web is full of self-styled experts. 6 quarts in a 5.1 quart crankcase is dangerous. Look at what an engine costs and when you consider the possibility of oil frothing or blowing out seals it unsettling to hear people say not to worry about it.


#11

Have experienced the same problem with some cars, but it’s generally easier if you wait until finished pumping gas, and it’s not likely to be a problem is the car has sat for several hours or overnight. My 2006 6-cyl. Subaru also appears to be sensitive to terrain level, varying a half qt. or more with seemingly mild surface tilts.


#12

I usually let it wait overnight, still difficult to read. Next time I’ll try for some photos.


#13

Actually encountered a severely overfilled oil pan (non-Subaru) just last year, the occupants had just added way too much (they initially thought they were off the stick low and simply added a lot) and pulled over a few miles later when the engine started running bad and they noticed a smoke screen coming out the back. The engine was hot, ticking, and 20 min. later the oil was so frothy the dip stick couldn’t be read. They had it towed.