Originally Posted By: artificialist
Originally Posted By: Silverado12
Maybe that's a Ford or import phenomenon. My GM's and Chrysler products have a rubber like O-ring (appears to be made into the plug) that I have never replaced. Didn't even know you had to and I've been changing oil for 35 years. My bike has an actual O-ring that I replace every time I change the oil.
I do occasionally have problems with the Chrysler style plug.
An Import thing? Yes. Toyota, Honda, Mitsubishi, Nissan, and VW have it, and there are probably others. It wouldn't surprise me if Subaru did it as well, but I don't change oil on Subarus often.
It may be different with certain models (and some cars that are merely rebadged), but most of the imports use specific OEM crush washers.
The one Toyota I changed oil on used an M10. The factory one I saw was aluminum but coated with paper on both sides. The dealer I went to sold fiber. I remember buying either copper at a local speed shop but got aluminum ones at a Honda dealer. They were for an older brake fitting and the parts guy said they rarely sold any.
Honda/Acura has always used an M14 aluminum crush washer that's made in Japan. Once I bought a bunch at a dealer and they were sealed in bags with the winged Honda motorcycle logo. I understand that Honda motorcycles use the exact same plug size.
I've changed a Nissan once. The dealer sells a unique looking M12 gasket made in Japan by some company called Ishino. They're really funky looking. The material itself is really thin, but it folds over to make three layers. I'm also not sure what's with the little notch. It looked like it dug in little scratches into the drain bolt. Also - my folks told me they took it to a local shop the last time for an oil change, but I found one of these things. I don't think they put on a new washer since I doubt they use this type.
Subaru uses an M20 steel crush washer like the kind you see on spark plugs. It's the widest oil drain plug hole I've ever seen. The manual transmission fill plug hole on Hondas are this size.
Of course these are basically all interchangeable. There's nothing special about aluminum, copper, steel, or fiber. I've occasionally used copper or aluminum on my Subaru. Dorman has copies of various gaskets, including that funky Nissan one. I bought a box of 10 of their Subaru equivalents, but they don't seal perfectly. They don't seep, but have tiny amounts of oil leak over time. There's an oil dirt coating near the plug and a little oil on the under spoiler. The ones I got are somewhat rough on one side and I don't think it's forming a perfect seal. I'm thinking of sanding down that side.