Stripped Oil Drain Plug: What to Do?

On most vehicles, the engine oil drain plug is located on the oil pan, which is typically made of steel. In these cases, any ol' auto tech at "Wherever Garage" can hardly screw it up. And even if they did, the worst-case scenario would be having to replace the oil pan, which isn't that big of a deal.

In all air- and water-cooled Vanagons (except for diesel), the oil drain plug screws right into the aluminum engine block. The thread size is 14mm, and it only takes about 10 ft.-lbs of torque and a new crush washer to do it right. There is nothing special about the crush washer, and no special tools are needed for the job. However, as easy as this job sounds, it's even easier to screw it up. That's why we NEVER recommend "Wherever Garage" for oil changes on these vehicles. You need to take your vehicle to a shop that understands the amount of torque and the crush washer needed for the job. It will make all the difference.

About 50% of the Vanagons that come through GoWesty have damaged or totally stripped-out oil drain plug holes. If the hole has not been too badly butchered, the easiest and best way to repair the drain hole is with a heli-coil. A heli-coil repair is the least intrusive method to fix such a failure, and the resulting repair is better than new. In other words, once a heli-coil is properly installed, the hole is almost strip-proof. The repair yields a threaded hole that is 5 to 10 times stronger than original. Still, an overzealous mechanic can strip one out, and then the hole will be too big for another heli-coil repair. At that point, a metal insert—also called a "time-sert"—is required, and even then, that can get stripped out. If the hole gets too big, a complete tear-down of the engine is often needed so that the hole can be welded up and re-drilled and re-tapped.

So why not go straight to the "proper" metal insert right from the get-go? Aren't heli-coils kind of hokey? 

Nothing could be further from the truth! Heli-coils have been used since WWII on aluminum aircraft engines. In fact, many threaded holes in aircraft engines and aluminum parts have heli-coils installed from the start. Porsche engines employ them all over the place. Furthermore, the threaded metal inserts are problematic for this repair. If the shoulder at the top of the insert is too large for the crush washer to cover, the oil will leak around the insert, around the crush washer, and right out. Inserts often come out with the drain plug! Heli-coils simply do not back out. Why some knowledgeable and otherwise well-educated/experienced professionals continue to bad-mouth the heli-coil is a mystery to us. 

The fact is this: The heli-coil repair is the way to go, and every GoWesty rebuilt engine gets one, stripped hole or not!

Note: GoWesty does not sell heli-coils. They come in a variety of sizes, and any good auto or tool supply shop should have them. 

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