On some engines, the oil drain plug has a molded-in gasket in a pocket under the head, while others may use an add-on gasket. Replacement plugs are available in auto parts stores such as NAPA. I replaced my plug last year because the soft head was getting chewed up. (It's a metric size head, but one of the SAE fractional inch wrenches is close in size and that may account for the chewing.) Also, there was a tendancy for oil change shops to over-tighten.

Be leery of the all-plastic plug. The hex corners are easily chewed and the head is easily cracked off from heavy handed wrenching.

Never changed one of my own. But had 2 Honda Accords that had to have a new gasket after every oil change. It started out as a drip now and then. The customer would noticed it in their driveway. And bring it back in. We would tighten the drain plug a little more. And the more you tighten it the worse it got. So with those 2 cars we changed the gasket every time we changed the oil. No problems with a new gasket. But use it twice and they would leak.

Thanks to both.

Yes that's my memory, the other cars/trucks I've owned/own must have the gasket built in somehow. In the case of the Forester it easily comes off, and when the plug drops in the oil catch pan I have to remember to fish out both the plug and the gasket. This never happens on other cars.

I shouldn't need to replace the whole plug, I'll check with Subaru parts to see if they sell the gasket, I bet they replace it ever time they change oil, and I now think I read something in the owner's manual about replacing the gasket and just sluffed it off as nonsense.

On Subaru's I replace the oil drain plug seal every time. For many others it's usually an inspect and replace as required. The large diameter Subrau drain plug poses a special problem that if you change oil enough times and never change that seal you will eventually have a plug that you know you tightened come loose, and fall out. The seal acts as a lockwasher, but only one time.

Most Subaru parts departments are so familliar with this, they will give you the seal with the oil filter. I buy the seals by the ten pack.....

John,

Thanks, good to "hear" from you again. I had no idea that there was a possibility of the plug falling out due to a failure of the "lock" function of the seal.

Jerry

Maybe once with the Saabs and VWs, going back 40 years now, but then no doubt, I have left a few drops here and there..
"Mechanics" and customers can be taught a lot better - when a plug "leaks" do NOT just over-tighten it, but tolerate a few oil drops and make it a point to change the plug washer..
The only oil drain plugs I have known to "fall out" were the ones never properly tightened in the first place !

And, what is this with the plastic drain plug ???
There are not nearly enough John Gs or JemDandys in the automotive world who know the physics of mechanics...and are willing to take a few extra seconds to apply them..

Back again. Doing a little web surfing I see advertised oil drain plug valves. For example I see a "FRAM Sure Drain" for $12.95 that puts an end to taking out and reinstalling drain plugs. The ad goes on to say the valve keeps the hot oil off of your hands, a nice extra.

I haven't checked the price of gaskets, but if they cost a dollar each the valve would pay for itself in about 6 years, and I will keep the car at leat that long.

Before trying something like that valve ask yourself a few questions.

1. If it's such a great idea, why don't they do it from the factory?

2. How well does it seal?

3. How does it get locked in the closed position, so that it does not accidently become open, or be opened by a saboture?

4. How susceptable is it to getting damaged and causing a leak on the road?

JMHO, drain valves are a bad idea especially on an engine that does not have an oil level float, has a rather exposed oil pan, and only holds about 4qts of oil.

Just remember too, while you'll spend $30.00 more for 100,000 miles of oil changes by replacing that seal (at your $1.00 a piece). One major oops could cost you $4000.00+

I have a few new oil drain plug gaskets, the local Subaru dealer gave me five, should have asked for more: >) at no charge. Now, I notice that the gasket has a flat side and a rounded side, the side that crushes. Which side goes toward the oil pan? I'd guess the rounded side. That way as the plug is screwed in it will work agains the flat side, not tearing at the crushable side. That's the only logic I can come up with to make my guess.

The Austin Allegro had plastic washers on the wheel studs to prevent overtightening (which would cause the wheel to fall off).

Would this be a reason for plastic washers on the oil drain plug ?

Before trying something like that valve ask yourself a few questions.
1. If it's such a great idea, why don't they do it from the factory?

Answer: Probably because they don't want to spend $5 on a part when they can use a $.05 part instead. They won't be involved with changing the oil so they don't care. Why do they often bury the heater core so it requires $500 - $1000 labor to replace a $40 part, when installing an access panel would turn it into a 1/2 hr job? Because an access panel isn't a good idea? Nope. It's because it would cost them a few bucks per vehicle, won't sell any more vehicles, and they won't be the one paying for the repair down the road anyway. I've replaced spark plugs in vehicles where I had to remove motor mounts and jack up the engine to get to some of them. The factory is full of great ideas.

2. How well does it seal?

Answer: The ones I've seen seal the same as a stock plug. They are available in stock thread sizes as well as self tapping.

3. How does it get locked in the closed position, so that it does not accidently become open, or be opened by a saboture?

Answer: The valve is a spring loaded affair that requires it to be pushed in to drain. The valve is covered with a screw on metal cap sealed by a rubber o-ring to prevent it from leaking and from being bumped by accident.

4. How susceptable is it to getting damaged and causing a leak on the road?

Answer: They do stick out about 1/2" further than a stock plug. A vehicle with low ground clearance where the pan plug is the closest thing to the ground wouldn't be a good place to use such a thing.

I've known a couple of guys who have these and say it's great for them. Remove the cap covering the valve, screw on the gizmo that comes with the kit that also includes a length of hose. As you screw on the gizmo, the valve is depressed and the oil drains out the hose to your container. It's a great idea on vehicles where the drain plug is located above a cross member or exhaust pipe where the oil typically splashes all over the place when you remove a stock plug. Not much of an advantage when the drain plug is unobstructed. jmo

I tried the Fram Sure drain and didn't like it. My plug was at the bottom of the pan and unobstructed. I spent more time unscrewing the cap. screwing in the other cap with the hose (which was hard to turn in all the way until the spring was pushed in - had to use a vise grip to turn). Then reverse it all when done. If done right, you will avoid some oil on your hands vs. removing the standard plug. But the hose was kind of curving up one time and the oil shot up over the edge of the drip pan.

Is there a good way to get the plug out without oil gushing on you hand? Anyway, after a couple of changes, I went back to the standard plug.

Latex gloves?

I try to change the oil hot, and find latex gloves an absolute necessity. They are enough heat protection if you let the plug drop in the oil pan and get you hand out of the way with only a second or two of exposure to the hot oil pouring out.

Here's one for you. I noticed that the was oil under my oil pan while there hot oil was draining. I raised the pan and saw it had a small hole. I quickly, luckly I had one, put a larger oil pan under the one that was leaking. Lesson, check the pan for leaks before using.

I just isntalled Qwik Oil Drain Valve and after that, I never replace the oil drain plug gasket because you don't have to take the plug off. Check the site:
www.qwikvalve.com
That's awesome.

Here is a link that might be useful: Qwik Valve

Caveat Emptor

"Caveat Emptor"

john g, Do you not like the concept in general, or this product in particular?

Looks ok to me as long as it's not located in a place where it could be knocked off while driving down the road.

I would have liked to have an option like that at the last garage job I had. Often times the plug was located above a cross member or steering linkages. Upon removing the drain plug, oil was going to splash out a couple feet in 6 different directions no matter what you did. Would have been nice to have some kind of valve with a nipple to attach a hose so that mess could be avoided in those cases.

I agree with tacomaniac, the Fumotovalves are awesome.

I've used them on every car i've owned starting with my 68 F-100.

Then there was my 80 Corolla

My 87 Ranger which i'm still driving with 240,000 miles on it. It's like the energizer bunny & just wont quit.

My wifes 92 Corolla

Her 95 Taurus.

And now her 2002 Sonata.

About 900,000 miles total & not a single problem with any of these Fumotovalves.