Drain plug question - what actually is leaking, threads or mating suface washer to pan?

[TiGeo]

I get weeping from the drain plug on my VW MK7 Golf Sportwagen. I have an aftermarket aluminum oil pan that uses an aluminum magnetic drain plug and single use aluminum crush washers. The recommended torque is ~20 ft lbs. Is the weep/leak from:

1) The threads (so you would say use HD teflon tape on them).

2) The mating surface where the crush washer should deform (I think?) to seal the drain plug against the pan.

Do I need to just tighten up (litterally!) and get that crush washer more deformed/tighten it more?

Don't forget folks, this post is set up on the forum using the "question" format so you can vote for the best answer with the arrows off to the right of folks' responses!

 

[TiGeo]

I see you used new pan bolts (because they're aluminum). Good man, @TiGeo!

Scott

I follow the manufacturer's guidance ha. They are torque to yield so one time.

 

[TiGeo]

I would probably give the mating surface on the pan a light scuffing with some scotchbrite and maybe also get a new drain plug. You could also try a copper or fibre washer instead of the aluminum one. I wouldn’t try higher torgue on the plug.

Drain plug is new.

 

[Exhaustgases]

I get weeping from the drain plug on my VW MK7 Golf Sportwagen. I have an aftermarket aluminum oil pan that uses an aluminum magnetic drain plug and single use aluminum crush washers. The recommended torque is ~20 ft lbs. Is the weep/leak from:

Yeah what could go wrong?
If that pan was made correctly the thread depth or length should be at least 3/4 inch long. Just wondering what idiot would have supplied that oil pan with an ALUMINUM drain plug? You won't find an aluminum plug in a Honda or Mazda, and they both have sufficient thread depth. It needs a steel plug. And to cure a leak its not rocket science or brain surgery, theres been cures for that I think many years before WW2. But like everything these days its all been forgotten.
Oh and I never have an oil drain plug leak, even using the same washer for years.

 

[Sequoiasoon]

I have some of these Toyota drain plug washers. They have a fiber/rubber coating on both sides of aluminum crush washer.

I think It's steel but FIL's Renegade has the drain plug with integrated O-ring in it and also doesn't call for much torque. Amazon has aftermarket with replacement gaskets.

 

[ATex7239]

#VWLife

 

[Kurtatron]

Don’t mean to go off topic, but this is another reason why drain valves are so nice. Torque them once. Never deal with leaks again, unless the valves go bad. I’ve got 2 fumotos and they haven’t leaked yet.

 

[Sequoiasoon]

I don't know how yours sits or if you are worried about slightly slower drain and the usual comments of leaving a small amount of oil due to design. Fumoto or Valvomax. I like them both, less worried about the Valvomax having an incident since it sits lower/closer to pan plus the cap on it. Fumoto on my Accord and past vehicles no issues. On my Pilot it hung way down and if no skid plate would have been right out ASAP. I changed to Valvomax on next drain anyway.

 

[TiGeo]

Yeah what could go wrong?
If that pan was made correctly the thread depth or length should be at least 3/4 inch long. Just wondering what idiot would have supplied that oil pan with an ALUMINUM drain plug? You won't find an aluminum plug in a Honda or Mazda, and they both have sufficient thread depth. It needs a steel plug. And to cure a leak its not rocket science or brain surgery, theres been cures for that I think many years before WW2. But like everything these days its all been forgotten.
Oh and I never have an oil drain plug leak, even using the same washer for years.

Wow if that triggered you that much check out the OEM drain plug for the factory pan on the VW/Audi 4 cylinders...plastic and plastic pans. Work perfectly BTW. I replaced it with the aluminum pan a few years ago.

I actually have a steel M18x1.5 mag drain plug with copper crush washer that I haven't tried yet. Not sure why steel vs. aluminum makes any difference here. It's plenty long (about an inch).

Finally please share this forgtten Boomer knowledge you have with the group on eliminating drain plug leaks that is being missed here. Thanks.

 

[Kira]

^^The 'coated' Toyota drain plug gaskets I've used were fine.

A plain washer style 18mm aluminum drain plug gasket has predominated in my world.
The drain plug has a shoulder which is smaller in diameter than the shoulder of the pan's drain port.
The metal deforms to affect the seal.

TiG: The aluminum used can be very thin. Perhaps you've thinned the metal too much?
What size do you use?

 

[Exhaustgases]

Wow if that triggered you that much check out the OEM drain plug for the factory pan on the VW/Audi 4 cylinders...plastic and plastic pans. Work perfectly BTW. I replaced it with the aluminum pan a few years ago.

View attachment 254277
I actually have a steel M18x1.5 mag drain plug with copper crush washer that I haven't tried yet. Not sure why steel vs. aluminum makes any difference here. It's plenty long (about an inch).
View attachment 254278
Finally please share this forgtten Boomer knowledge you have with the group on eliminating drain plug leaks that is being missed here. Thanks.

Aluminum is soft material. It makes a very weak bolt. Just that simple.
That plastic plug is more of a simple lock tab that likely clicks in the hole using light torque the oring seals it, I'd rather that than have a threaded aluminum plug, that could shear off.

 

[TiGeo]

^^The 'coated' Toyota drain plug gaskets I've used were fine.

A plain washer style 18mm aluminum drain plug gasket has predominated in my world.
The drain plug has a shoulder which is smaller in diameter than the shoulder of the pan's drain port.
The metal deforms to affect the seal.

TiG: The aluminum used can be very thin. Perhaps you've thinned the metal too much?
What size do you use?

Drain plug is M18x1.5. Just whatever aluminum crush washers it came with...normal ones? Haha. They are pretty thin. I just measured one it's 1.3mm thick. I replace it each time.

 

[930.engineering]

I get weeping from the drain plug on my VW MK7 Golf Sportwagen. I have an aftermarket aluminum oil pan that uses an aluminum magnetic drain plug and single use aluminum crush washers.

Which exact "aftermarket aluminum oil pan"? American made or far east?
There's some chance the mating surface isn't at an angle of 90 degrees to
the bore and thread. Next, your not so soft Al washer couldn't compensate
for the present deviation.

The recommended torque is ~20 ft lbs.

Keep using ~20 ft lbs please because aluminum pan thread.

Is the weep/leak from:

1) The threads (so you would say use HD teflon tape on them).

2) The mating surface where the crush washer should deform (I think?) to seal the drain plug against the pan.

I'd bet it's both.

So Teflon tape won't help, but a different "washer" might solve your problem.
I use to use for at least five years ELRING #813.052 without any complaints.

When you remove it later it'll be flat like a post stamp - literally.

Do I need to just tighten up (litterally!) and get that crush washer more deformed/tighten it more?

Never please! Unless you love to strip this thread.

Don't forget folks, this post is set up on the forum using the "question" format so you can vote for the best answer with the arrows off to the right of folks' responses!

Too late. It doesn't even help to express my thoughts.
.

 

[TiGeo]

Which exact "aftermarket aluminum oil pan"? American made or far east?
There's some chance the mating surface isn't at an angle of 90 degrees to
the bore and thread. Next, your not so soft Al washer couldn't compensate
for the present deviation.



Keep using ~20 ft lbs please because aluminum pan thread.




I'd bet it's both.

So Teflon tape won't help, but a different "washer" might solve your problem.
I use to use for at least five years ELRING #813.052 without any complaints.

View attachment 254286View attachment 254287

When you remove it later it'll be flat like a post stamp - literally.




Never please! Unless you love to strip this thread.




Too late. It doesn't even help to express my thoughts.
.

The pan is a quality piece from Üro...they make decent aftermarket Euro car parts.

At this point I'm good...need to focus on the washer.

 

[Chris142]

Just a month ago when I did the oil change last, I think I'm scared to actually tighten it enough b/c the pan is aluminum (but so is the drain plug).

Your not going to strip anything unless you are absolutely clueless.

 

[Vercingetorix]

Just wondering what idiot would have supplied that oil pan with an ALUMINUM drain plug?

Porsche uses aluminum drain plugs. I don’t think they are idiots.

 

[TiGeo]

Your not going to strip anything unless you are absolutely clueless.

You are giving me WAY too much credit hahaha...yes, I think your'e right, it's an 18mm solid bolt into a nice thick pan, it shouldn't just strip out.

 

[kschachn]

The pan is a quality piece from Üro...they make decent aftermarket Euro car parts.

We’ll have to agree to disagree on that one

 

[TiGeo]

We’ll have to agree to disagree on that one

My son just got a new coil pack for his '98 MK8 GTI that was Uro branded, looks ok to me? Are these crappy?

 

[kschachn]

My son just got a new coil pack for his '98 MK8 GTI that was Uro branded, looks ok to me? Are these crappy?

Well perhaps you’ll have better luck than I did on my BMW.

 

[TiGeo]

Well perhaps you’ll have better luck than I did on my BMW.

What parts did you have that you had issues with? I figure an oil pan...how hard can that be haha.