Rick's Free Auto Repair Advice

Repair a stripped oil drain plug

Options to repair a stripped oil drain plug

Overtighten the oil drain plug, and you can strip the threads out of the oil pan. Once that happens, you’ll leak oil. Here are the four options to repair a stripped drain plug.

Fix a stripped oil drain plug by replacing the oil pan

This is the best but most costly solution.

Fix a stripped oil drain by installing a TimeSert insert

This costs more than the other methods but provides

timesert oil drain pan plug kit

TimeSert Oil pan drain plug kit

a permanent solution. The kit comes with a drill bit, tap and insert. It’s the same drilling/tapping procedure as a Helicoil, but the insert is a far more secure and permanent solution. This is what I recommend.

Before you can buy a TimeSert kit, you’ll need

to know the size of your oil pan drain plug. See this chart to find the size. Then purchase a TimeSert kit here.

What is an oil drain plug insert?

An insert isn’t like a wound spool of wire like a Helicoil. It s a solid insert that threads into the oil pan and has internal threads for the new oil drain plug. They’re made by Timesert.com. Timersert makes all kinds of inserts for stripped spark plugs, oil drain plugs, and engine drain plugs.

The kit contains a drill bit to oversize the existing oil drain hole, a counter-bore seat cutter to recess the insert into the pan, a tap to cut new threads for the insert, and the insert/tap guide installation tool.Timesert oil drain plug kit

Timesert oil drain plug kit

Steps to installing a Timesert oil drain plug replacement

Step 1: Using a standard tap holder tool, use the Timesert drill bit from the kit to cut the existing hole larger. Fill the drill flutes with grease to capture the metal fragments.

Step 2: Insert the counter-bore tool into the tap holder tool and cut a recess into the oil pan. Remove any metal chips from the newly bored hole.

Step 3: Insert the tap into the tap holder. Lubricate the threads and insert the tap into the tap guide. That will help the tap go in straight. Tap new threads. Remove the tap and clean out any metal chips.

Step 4: Screw the insert into the new threads. Then use the driver tool to run the insert all the way in until it seats in the counter-bored hole.

Timesert Installed

Timesert Installed

Self Tapping Oversize drain plug

An oversize drain plug is a combination drain plug and tap that cuts new threads into your existing oil pan. You simply start the new plug into the old thread and tighten. The tapered end literally

oversize oil drain plug

Dorman Brand Oversize Oil Drain Plug

cuts new threads into the oil pan and the upper portion of the bolt seals against the pan. Does it work? Yes. Does it last? Yes, but only for about 6 oil changes. Here’s why:

1. To work properly, the oversized drain plug must be perfectly square to the stripped opening. If it’s not, the new bolt head won’t sit flush with your oil pan and it won’t seal.

2. It cuts shallow threads. To retap a hole properly, you really need to drill out the old threads and use a tap that cuts deep enough into the metal to make real threads. An oversize drain plug simply doesn’t cut deep enough threads. It’s a temporary fix.

Helicoil insert for new oil pan drain plug

A helicoil is a great way to fix stripped threads. You drill the stripped threads out, tap threads into the new hole, then thread in the heli-coil. This method works for most applications. But it isn’t the best solution for oil drain plugs. Here’s why. The helicoil is constantly submerged in oil. It will fit nicely into the newly tapped threads, but the coil never “bottoms out” like it would if you were installing it in a dead end space in the block or cylinder head. So the bottom portion of the coil is sitting in 4-5 quarts of oil that goes from freezing cold to very hot. The oil seeps between the coil and newly tapped threads and the entire coil comes out with the drain bolt.

Expanding rubber oil drain plug

Several companies make a rubber oil drain plug that rubber oil drain plugfit into the oil pan opening and expands as you tighten the hex nut. They’re cheap, but they don’t last. They’re a temporary fix. Yeah, they’ll get you out of a jamb. Never count on a rubber plug for the long term.

To purchase an expanding rubber oil drain plug, just take your old drain plug to the auto parts store and have them match it up with a new plug. OR, refer to this oil drain plug size chart

JB Weld and oversize oil pan drain plug

I see this a lot on forums. Guys use the oversize bolt to tap new threads. Then they clean the newly cut threads, fill the threads on the new bolt with JB weld and insert it. The theory is that the epoxy fills in the gaps. Personally, I think this is a stupid idea. I’d rather fix it right the first time.

Things to keep in mind.

An oil leak from the drain plug can cause your engine to run dry. That will destroy your engine.

If do a cheap fix, you risk destroying your engine.

Do it right or don’t do it at all

©, 2019 Rick Muscoplat

Posted on by Rick Muscoplat

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