have a small leak at the drain plug on my 97 2.2 Impreza.  Tried a new plug and washer but still leak a tiny amount.  Seems as though the washer is only flush to pan about 3/4 around.  Pan doesn't seem out of round but can't get the new washer totally flush.

 

Plug threads in easy enough no undue force needed.

 

Appreciate any suggestions.  Thanks

Subaru Parts?

 

The metal crush gasket should seal fine.  If not I'd pull the plug and check the hole for defects, dented, cracked...

 

Pretty thick metal so you could sand flat if needed.

Replacement is aftermarket.  New gasket is much thicker, thought that would be better.  Suggest getting a new plug/gasket from the dealer?

Yes, Subaru parts!

I put a Fumoto Valve on my Outback over 10 years ago and have never had a problem with leaks. 

get a Subaru drain plug gasket (washer).

if the drain plug isn't Subaru, get a Subaru drain plug.

i've seen aftermarket plugs and gaskets leak.

clean the mating surface up really good on the oil pan.

 

i never replace Subaru drain plug gaskets (the washer) - i've run them over 100,000 miles many many times.  get Subaru parts and be done with it.

Also, the washer is direction specific. The larger flat side goes to the nut. If reversed, it will leak.

 

O.

Edited October 13, 201411 yr by ocei77

got the new plug and crush washer.  oriented the washed as mentioned.  much better but still a slight leak.  Weird, never struggled with this on any other Subaru.  Any thoughts?  Is thread sealant or Teflon an option to try and stop it completely?

The seat for the drain plug is clean and flat? What type of washer are you using? Copper works best on these. Aluminum works also but not as well.

I've seen the area under the plug flange pitted and galled from having the plug tightened down with dirt still on the pan or under the plug flange. This usually needs to be cleaned up with a fine file or sand paper. Wipe a blob of grease in the hole to keep shaving and dirt out of the threads.

 

I've seen people glue/seal the washers to the pan. This makes it more of a pain to get it to seal next time since the glue doesn't really hold. The washer falls off and then you have to clean it and re-glue it.

Couold the pan have a pinhole or tiny crack near the plug?

 

I noticed on mine the threads are made from a piece spotwelded to the pan.