Oil Weight Question
 

I have a question with oil weight. If i have a car with high miles on it, and I'm using a lighter oil weight is it possible for the oil to seap through the main seals because of it's thickness?

I doubt that changing the weight will keep it from leaking if it already is. Did it just start leaking after you did an oil change or was it leaking and you're hoping you can go to a thicker weight to keep it from doing so?

It started leaking after i changed out the oil to a thinner weight. It wasn't leaking before.

What weight did you put in it and what did it have in it before?

I had 10w30 in there before, and then i had like 9 quarts of 5w30 laying around so i threw it in there. After i ran it for a while, i noticed that oil started leaking slowly out. Not very much but a couple drops a day.

I'm not planning on keeping it in there, just figured i had it so i would use it. If it's going to cause problems or a leak i will change it out right away. i Haven't been mashing on the gas, just driving like an old lady.

Wait. How many quarts did you put in and in what car was this? There is very little difference between 10w30 and 5w30. Not enough to be the cause of the leak.

The only difference is on start up, once it's warm they are the same weight. Maybe you should try high mileage oil or add some Prestone oil additives.

Well the engine capacity for my Volvo is 5.6 quarts. It's a 1996 Volvo 850r, 2.3 litre turbo. It does have pretty high miles on it 200xxx

Edit: It was 5w20 not 5w30.