Ideally an oil drain plug should always thread in and out easily. It isn’t a structural fastener, just a plug to hold back fluid. But it can be awkward laying under a car trying to get an oil drain plug started when you feel a little resistance. Maybe it is just a piece of crud and the plug will free up in another turn. Except it doesn’t free up and now it is tight and nowhere near seated. Or just as bad the plug now turns freely but doesn’t seat. Now you have a problem. Let’s take a look at how to fix a cross threaded oil drain plug and other oil drain plug problems.
How To Fix Cross Threaded Oil Drain Plug
If your oil drain plug starts to tighten up before it is seated against the oil pan drain hole, it is probably cross threaded. At the very first sign of resistance you need to stop tightening the plug and back it out again. Once the oil drain plug has been removed you will need to repair the oil drain plug hole threads with a thread restoration tool. This special tool typically comes as a kit with several different thread sizes. Pick the repair tool with the thread size that matches your oil drain plug. Apply a few drops of lubricant to the repair tool and gently thread it into the oil drain plug hole turning it slowly by hand. The repair tool will repair the threads as it goes. Be careful to not allow the repair tool to pass completely through the oil pan drain plug hole, stay within the threaded area. Use a new oil pan drain plug (the old one may be damaged) and thread it in gently by hand to verify the repair.
How To Fix A Stripped Oil Drain Plug Hole
The first step in how to fix stripped oil drain plugs is to not panic. Once you realize that the oil drain plug won’t tighten, immediately stop turning it. Try to reverse the drain plug out of the hole by hand. If the drain plug only spins in place but does not back out, try inserting a flat-tip screwdriver blade behind the head of the bolt and gently prying away from the pan. Turn the drain plug slowly to help the remaining threads catch on the drain hole. The plug should come out.
Once the drain plug is out it is best to just replace it with a new one. To address the stripped oil drain plug hole you have a few options. You can install a thread repair kit to renew the drain threads. You can also use an oversized drain plug or a piggyback oil drain plug. Lastly you can try drilling and tapping the drain hole for a larger drain plug, but this is best done with the oil pan removed from the vehicle to contain any metal shavings.
How To Fix A Stripped Oil Pan Drain Plug
The easiest answer to “how to fix stripped oil drain plugs” is to simply replace the plug with a new one. A new oil drain plug is cheap insurance against a potential oil leak. While it is entirely possible to repair screw threads, the cheap cost of a new drain plug isn’t worth gambling with your engine’s lifeblood.
Oil Pan Replacement
If all else fails then the only solution is an oil pan replacement. Depending on how your vehicle was engineered this may be an easy job requiring removing just a few oil pan bolts, or it could require removing the entire engine from the vehicle. Some newer vehicles have plastic oil pans which may not be repairable with common methods.
If none of these methods work you can always try a universal oil drain plug. These types of plugs are meant to seal the oil drain hole regardless of the thread conditions. Resist the temptation to use sealants as they might leak back into the oil pan and clog the oil pump pickup. You will still need to perform routine maintenance on your engine, so whichever route you take make sure the oil can still be drained in the future.
Check out all the tools & equipment available on NAPAonline or trust one of our 17,000 NAPA Auto Care locations for routine maintenance and repairs. For more information on how to fix stripped oil drain plug threads, chat with a knowledgeable expert at your local NAPA Auto Parts store.
With an automotive writing career spanning over two decades, Brian has a passion for sharing the automotive lifestyle. An avid DIYer he can usually be found working on one of his many project cars. His current collection includes a 1969 Olds Delta 88 convertible, BMW E46 sedan, and a slant-6 powered 1975 Plymouth Duster.