2017 Subaru Outback Oil Drain Plug Head Rounded - First Oil Change

This seems to be a common problem - first oil change on a late model Subaru 2.5L engine - and the oil pan drain plug head gets rounded by your socket and you can't remove the drain plug. So - what to do? Trip to the dealer? I've been changing my own oil for many years - first time this has happenned to me. I decided to purchase a set of bolt extractors and sort it out myself. Here's how it went.

14mm Hex Head on the Drain Plug - Just rounded enough to make it impossible to remove

 I purchased a slightly used 2017 Outback with 17,000 km - lease return. At 25,000km I went to do my first oil change. The dealer had informed me that they had changed the oil at the lease return. When I went to remove the drain plug - I didn't lift the car because I thought I'd be able to spin it off with the car sitting on the ground (as I had done many times with my 2006 Outback - it sits high enough off the ground that you can slide the pan underneath and not have to lift the car to change the oil). This time it went differently - with the drain plug at an angle, and recessed slightly below the aerodynamic underbody cover - it's quite awkward to get a socket on the drain plug and apply the torque at an angle. It would be much easier with the drain plug oriented vertically. One bad move and I rounded the head.

Another view - Drain Plug accessible through a small access port, sits on an angle

 So - I put everything away, got online and ordered a set of chinesium bolt extractors. I've never tried these before, so this was an experiment for me. Using a ball pien hammer, I tapped the 14mm extractor onto the drain plug so that it was well seated, then popped on a short extension and used my Dewalt 3/8" impact gun which can generate about 100 ft-lbs of torque - and nothing moved - at all. I was stunned - 100 ft-lb of torque on a drain plug? Clearly not normal.

Dewalt 1/2" Drive Impact, 21mm deep socket, 14mm bolt extractor, and the drain plug in question

So - I pulled out the Dewalt 1/2" impact which can generate 400 ft-lbs of torque - and a 21mm deep impact socket to be able to fit over the extractor (instead of using the 3/8 socket drive square) and leaned on it. After about 15 seconds, the drain plug broke free and loosened, with no damage to the oil pan. The bolt extractor was hot to the touch from the impact force. The drain plug was well grooved from the force of the bolt extractor.

Check out the grooves on this drain plug head. Exctractor worked like a charm.

I installed a new Dorman replacement drain plug - with a larger hex head - and completed the oil change.

Bit of a mess - An angled drain plug will shoot your oil about 2 feet sideways

So - what do I think about this? Drain plug with small head - should be larger - like 19mm for a 16mm bolt size so that you can get a tool on the drain plug. Soft metal and the paint interferes with good contact with your socket. This plug should definitely be re-specified. The plug installed on an angle - shooting oil sideways? Brutal - plug should be installed vertically on the pan. I don't know if the dealer ever actually changed the oil - have sent the oil out for analysis to get an opinion on that. If you're in the same situation - up to you to decide what to do - take it to a dealer or extract the plug yourself. In my case - it worked out okay. Let me know if you have any questions.

In case you're wondering, the new drain plug is a Dorman 65325 - M16-1.50 threads. Nice piece with 17mm hex head - 3mm larger than the stock drain plug.

Dorman 65325 Oil Drain Plug

Update - December 2019:

6 months have gone by, did my second oil change. Drain plug spun off normally, no problem at all, oil change completed in 30 minutes. Definitely a manufacturing defect with the way the drain plug was delivered from the factory. Blackstone Labs oil analysis came back on the first oil change - they did not think that the oil had not been changed as described by the dealer - which was good news. It also meant that they must have sucked the oil oil out of the dipstick tube. FWIW.

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