Hi, I have a 2004 Honda Civic LX manual transmission with 200,000 miles on it. I bought the car about 4 years ago with 160,000 miles. When I bought the car the oil pan was rusted so I had a mechanic replace it and she used an aftermarket pan. Immediately after, there was a small leak around the pan but I move a lot for my job so I didn't return to the mechanic to have it looked at or redone. I had a smallish leak for about three years then finally decided to have the oil pan gasket replaced about 8 months ago (at a different shop). This replacement lasted about two months, then there was a lot of oil leaking from the oil pan gasket area. I had another mechanic replace it again. That lasted about 4 months then another sizeable leak from the gasket. Just last month I had it done again at yet another mechanic and now the leaking oil from the pan/gasket is worse than ever.

I explained the history of the problem to each mechanic and each said the previous mechanic probably over-tightened or didn't use silicone bead in addition to gasket etc. etc. They also checked the pan and said it looked fine- not warped or uneven. I even told the last mechanic to use a new pan anyway but he was confident if the job was done right the leaking would stop (his job lasted the shortest amount of time with the worst leaking). But all of these mechanics were very experienced and seemed knowledgeable and had many very good Google reviews.

I am going to have it done one more time with a new pan (but Honda no longer has a pan available for this car so I will have to use aftermarket again). My question is (finally), I understand that if there is a fault in the pan it will not provide a good seal and leak. But why does the leaking stop for 2-4 months and then start leaking again? The pan is held to the under part of the car by about 15 bolts so it can't, I wouldn't think. be moving once it is tightened, so why does the leaking stop and then start again after several months? It is my understanding (though I may be wrong- just going by online research) that pressure does not build up in the oil pan so pressure shouldn't be a cause of gasket failure.

Thanks for any ideas- I really do appreciate the people who take the time to answer these questions. If a new pan doesn't fix the problem I am going to have to get rid of the car because I can't spend $350 every few months for a new gasket, but it seems insane to have to get rid of a car due to a leaking oil pan gasket.