I sent an oil pan out to my machinist to fix a bad oil pan plug. The threads were pretty bad, and the incorrect plug  was barely able to keep oil from leaking out. I bought a correct Ferrari drain plug and sent it along with the oil pan to the machinist.

There were several ways to fix this problem. One, the old threads could have been drilled out, and a threaded insert could have been used. Two, the hole could have been aluminum welded and new threads could have been cut to accept the new correctly sized oil plug. Three, the hole could be enlarged and new threads cut to the next size up and an over sized plug installed. There are pros and cons to each of these methods and we had to choose the best solution.

Putting a threaded insert to fix drain plug threads is a common repair and they even sell kits at the auto parts store because it’s such a common problem. I’m not a fan of the coiled thread repair kits made by helicoil, and would prefer a solid insert like Timesert, but the insert has to be leak free to work for a drain plug. Welding the hole would require making sure the surrounding material was very clean to accept new weld. Any impurities would cause the repaired area to be porous and leak. The final choice was to drill and tap the next size hole to accept an oversized drain plug which is what we went with for this repair. My machinist made an exact copy of the Ferrari plug except for the size of the threads. There was plenty of sealing surface to allow a gasket to do its job sealing the bottom of the pan.

I cleaned the sealing surfaces of the oil pan to prepare the re-installation of the oil pan. I tried my best to make sure every spec of dirt, old gaskets, and oil was removed from this area because this is a common place for oil leaks.

TomYang.net Monterey Cocktail Party

This year’s Vintage Ferrari Party is being generously co-hosted with Larry and Kristy Hernandez in Pacific Grove, CA on August 15th at 6pm. Contact Tom for location details. I will provide some food and drinks, but feel free to bring something to drink to share at the party!

See you all in Monterey!