Oil leak mystery, from engine block banjo feed to turbo

[vizSub]

I have a mystery regarding an oil leak from the banjo bolt (12mm x 1.25) on the rear RHS of the engine, Outback 2009 2.5 XT.

 

- new short block installed after rod bearing failure.

 

- shop mechanic that did short block did not replace oil cooler, oil pump, AVCS cam pulleys, oil pan. bad shop mechanic!

 

- No oil leak when I got car back from shop mechanic.

 

- After I replaced the oil pump, oil cooler, AVCS pulleys, oil pan (Killer B pan), turned the engine over and massive leak from the banjo bolt. Weird since I did not touch my turbo lines after the engine replace, and I did not have the leak until after I replaced these parts. (Turbo is aftermarket 18G with stainless oil lines and pre-turbo filter).

 

- I spent today putting new 12mm copper crush washers, from Subaru, on the leaking banjo. Still leaks, drips now instead of stream of oil leaking.

 

- Tightened the banjo bolt again and again, recommended torque (IAG) is 24 ft lbs. I did not get a torque wrench on there, since the only wrench I can get on it is a flex-head 17mm ratcheting box wrench. I cranked pretty hard and did it after the engine warmed up a bit. Still leaks...

 

Suspects:

 

1) too much oil in the new oil pan, dipstick reads high now, Killer B says the new pan holds an additional 1.4 quarts. --> drain it and measure 5 + 1.4 quarts... not sure this would cause a leak though?

 

2) the new oil pump is a 11mm, same as the stock. Perhaps more oil pressure than before and hence the leak?

 

3) Crush washers? Took me forever to find some that fit, these are 12mm. I got them from Subaru. The only ones they had were thin. If you look at the IAG website their turbo oil line kit discusses a thicker 12mm crush washer that goes up against the engine. I no longer have one of these, the mechanic replaced it with the same thinner ones I picked up from Subaru today.

 

My bet is the crush washer thickness, since I did see the leak get slower when I replaced the crush washer (always do this..), however I have so much torque on it now I do not want to go any tighter.

 

So far I have yet to find thicker crush washers. Auto Zone, O'Reily both have the same brand / package of assorted crush washers, none of them are thick. Subaru dealer did not have the thicker crush washers.

 

Any suggestions appreciated!

[relative4]

Buy a new banjo bolt, I believe it comes with washers. Obviously pull the screen.

Check the old banjo bolt, fitting, and head surface for cracks or scratches.

Is the right bolt definitely in there?

[vizSub]

Buy a new banjo bolt, I believe it comes with washers. Obviously pull the screen.

Check the old banjo bolt, fitting, and head surface for cracks or scratches.

Is the right bolt definitely in there?

 

It is the correct banjo bolt. Torqued it some more and the leak slows down, but does not stop.

 

I think the problem is the copper crush washer on the side of the engine block needs to be M12 x 18mm x 1.5 mm instead of what I got from Subaru M12 x 18mm x 1.0 mm. The 4AN hose fitting barely touches the block and I believe this is preventing the compression of the banjo crush washers completely.

 

Hard to find the correct, thicker, crush washer in auto parts store.

 

Here is a link to them on Amazon.

 

Note that I ran the IAG turbo oil feed lines after replacing my turbo and removing the stock hard lines, so the issue of the hose fittings running up along the block is a feature of using oil hoses (4AN ) and fittings.

 

Will wait for new, thicker, crush washers to arrive and see how that goes.

[Infosecdad]

Do you have any extra copper washers? Can you try doubling up on the block side?

[vizSub]

Do you have any extra copper washers? Can you try doubling up on the block side?

 

That was my "Plan B". I think that would work, perhaps with some high-temp gasket sealer between the two washers. That would push the fitting of the oil line away from the block.

 

Today I was able to get the correct washers, finally. What a challenge!

 

For other's information the correct size copper washer for the block side of the engine is 12 mm x 18mm x 1.5mm (or thicker 1.5mm - 2mm).

 

I finally stopped the leak tonight using the thicker washer, and making sure the oil line hose and fitting were orientated so they did not touch the engine block. Easier said than done! I ended up having the oil line run directly vertical down to the banjo bolt. Then hold it in place with help from my wife, using a long pry bar, while I tightened the banjo with a flex head ratcheting 17mm wrench.

 

In this vertical orientation the amount of torque required to seal it was minimal compared to what I was applying earlier (and still getting a drip leak). This tells me the problem was the hose fitting against the block, ever so slightly, was not letting the crush washer lie flat.

 

I struck out finding the correct copper crush washers at 5 different auto parts stores, and a Subaru dealer. The big name (chain stores) only had sealed boxes of assorted crush washers -- none were correct. What worked was buying an assortment box from Amazon that had both the 12mm x 18mm x 1.5mm (engine block side) and the 12mm x 18mm x 1.0 mm (other side of the banjo, away from engine).

 

This entire exercise has been "fun". I am looking into taking off the banjo bolt from the back of the engine block and using a fitting like this one, from Earl's (a 90 deg elbow, with M12 x 1.25 threads on one side to go into the block, and a 6AN hose fitting on the other side. (I have yet to find a 4AN x M12 1.25 elbow). If this elbow will fit, and not hit the flange for the up-pipe of the turbo (?), then I think it would be much better than these banjo fittings.

 

Thanks to an earlier poster that mentioned using a flex-head ratcheting wrench. This was the key! I tried stubby ratchets, swivel-head sockets, shallow depth sockets, flex-head ratchets, and lots of wrenches with no luck. The flex-head ratcheting 17 mm box wrench was a savior.

 

Thanks for all your suggestions.

[relative4]

Funny, I've always had no problem using a straight box ratchet. It slips right between the head and that line that runs vertically near the valve cover.