Oil change problem...

[mike270]

This has always happened on both my Subaru's...

When checking it before driving it, the level is perfect (after pulling it, wiping it and pulling it again). Then after going for a drive, I repeat the process (pull it, wipe it, and pull it again) and the level is WAY over the full mark. After then letting the car sit again overnight I again check the oil and its back to the full mark again.

I think this is simply due to oil expansion. Doing a bit of searching, it looks like there is in fact a fairly significant amount of expansion that takes place in oil at room temp vs operating temp.

So that tells me that oil should always be measured when cold and if you check it when hot, you WANT to see it well above the full mark. If you start taking oil out to get it to the full mark when hot, I'm going to guess that you are actually making your engine run low on oil.

I'm also guessing that this scenario is exactly what the top notch on the dip stick is for...

[t3h L3g4cy]

I had the crush washer on my car leak. However I don't know how old it was; could have been original

Damn that's a long time to have a crush washer. I agree with ciper that ur supposed to replace them every time u go get an oil change but i find that to be impractical. I mean it's not like if u don't replace the crush washer every time, the oil is gonna leak. Replacing it once or twice a year should be sufficient. At least thats wat i do.

[mike270]

Its simple enough...whenever you buy a filter, buy a crush washer. They are only $.50 or something, and since you are there anyway you might as well replace it.

[IronMonkeyL255]

I just bought a pack of copper washers and re-anneal them after every oil change or two.

[ciper]

This is why a Fumoto comes in handy. Use a new washer and never look back.