Oil leaking...sometimes

So about a month and a half ago I noticed a couple small dots of oil under my car after it had been sitting for a day. Then the next day about 10 more dots dropped overnight. It has not leaked anything since, until this past Saturday night. I came back from church Sunday morning and noticed a pretty good sized oil spot underneath where my car had been parked overnight. It sat parked for over a day and this amount of oil leaked out in that time (see pic, ignore the larger dried up oil spot). Now it is Tuesday and it has not leaked any oil since then. After the first time I noticed it leaking the few dots and then the ten or so dots of oil, I asked about this when I went into have it serviced. They didn't see any leaks and said they could address it at my next oil change. They said my lower oil pan may need to be replaced. When my brother in law last changed my oil, he couldn't get the oil plug in the filter loose so he had to pull out the entire filter to drain the oil. Apparently the screw to take out that plug where the filter is was stripped or something, and because of this the service guy said I may have a tiny leak there and that replacing the lower oil pan would fix it...My question is, why is the oil leaking at such spread apart times and in such different amounts? What could cause this, and would replacing the lower oil pan fix it?

Unfortunately, it could be many things. Like for instance, the alternator gasket, automatic transmission oil pan, deteriorated seals in the engine, and many other causes.

Oil leaks at random intervals in differing amounts because there is a belly pan on the car. Oil accumulates in the pan and only drips if the inclination of the car is right, or if wind has or hasn't accumulated oil in one part of it. This probably means it isn't the oil plug or filter as these would drain into the mini cover in the belly pan, and would be less likely to be intermittent.

Are you sure it is motor oil and not tranny fluid? Looks kind of red in your picture? The smell usually gives it away.

Originally Posted by Skarv

Oil leaks at random intervals in differing amounts because there is a belly pan on the car. Oil accumulates in the pan and only drips if the inclination of the car is right, or if wind has or hasn't accumulated oil in one part of it. This probably means it isn't the oil plug or filter as these would drain into the mini cover in the belly pan, and would be less likely to be intermittent.

Are you sure it is motor oil and not tranny fluid? Looks kind of red in your picture? The smell usually gives it away.

It was definitely oil, it looked red in the pic but was def brown on the rag. When my brother in law did my oil change he apparently didn't tighten the oil plug or filter (can't remember which one) all the way so he tightened it and it hasn't leaked anything since. I also took it in to the dealership the other day to have a "used car inspection" done on it and they didn't see any leaks either. Not sure how it leaked intermittently like that if it was a loose plug/filter, but here's to no more oil leaks!