Replace oil pressure switch (sensor)

[39 of 500]

I noticed that the oil pressure light came on when I was rolling backwards in neutral a couple of weeks ago. At the time I freaked out, and I damn near cracked a rib trying to shut the card off. I then gave it a thorough going over and everything seemed ok, still hesitant to turn the car over I googled it to see what I could come up with. I eventually narrowed it down to the oil pressure switch (I'd call it a sensor but every one seems to call it a switch). Next time I found myself near a local dealer I ordered one ($32) and picked it up a couple of weeks ago. I finally got around to putting it in today (I have kids). I had looked around the web for a good overview of what I was in for and was surprised when I didn't find one. There may be one here already that I missed, but in the event there isn't I figured I would make one. I've used enough of them, I suppose it's my turn to give back...

Of course there is a caveat. While looking it over I thought I could get the switch out without removing the alternator. It's true, it was possible, but after having done it I would remove the alternator if ever I needed to do it again.

 

What I needed:

Torque Wrench (I'd never consider it optional, especially on engine work)

regular socket wrench(should never loosen with a torque)

24mm deep socket

17mm standard wrench (not a socket)

about 9 inches of extenders (if not removing the alternator, but you should)

needle nose pliers

Rags (wasn't oily or dirty, just always handy)

 

Had I taken off the alternator I would also have needed an additional wrench/socket. In my experience these are usually 10, 12 or 14 mm.

 

Here is the overview of the engine:

 

Overview.jpg

 

 

Here is a closeup on the left side of the alternator:

 

Closeup.jpg

 

 

Here is the part after it came out:

 

part.jpg

 

This is actually two separate pieces. The part with the tab is the sensor (24mm deep socket). Had I taken off the alternator I would have noticed and separated the actual sensor from the anchor (17mm) leaving the anchor in the block. Since I had already removed it and the part was out, I separated them and screwed the sensor into the anchor and then screwed the anchor back in. There is an aluminum washer in between the anchor and the block. That's what I used the pliers for.

Since I had removed them without taking off the alternator I figured I would try and get them back on the same way and was able to by tightening the unit by hand before applying the torque wrench.

 

The torque on the sensor is 18lbs. Here is a handy site, this is a link to the EJ25 block version:

http://www.torkspec.com/torkspecme.aspx?KI=40-2.5L-150ci-F4

 

I let it run for about 20 and gave it some good revs, no leaks thus far, I'm going to have to check it pretty regular for a couple of weeks since I wasn't sure if the anchor bolt has the same torque as the sensor. if anything goes tragically wrong I'll update.

[dr_sharp]

Nice write up. You might consider having a mod move this to the walkthrough section, though.

 

A friend and I have been discussing replacing this switch with one that will trigger at a higher pressure, say 15psi, so that the oil pressure light is more of a warning light rather than a light that informs you when your motor has <50 miles of life left.

[dr_sharp]

Do you have a part number for the switch?

[dustincredible]

Even though this topic doesn't fit in this section (no worries, noob member), thanks for the write up!

[39 of 500]

Sorry, about the location. I noticed after I posted it that when I scrolled down the list to select where to post it I selected 4th gen pictures instead of 4th gen general...oops.

If the moderator stumbles across it and feels like moving it, feel free, I posted it here in error.

Sorry, I no longer have the part number, I cleaned out my car a few days ago before a trip and I threw the receipt out. The parts guy at my local dealer is far from the sharpest knife and he didn't have much difficulty locating it. If memory serves virtually every Subaru uses the same part number for the switch.

I've gone about 1,000 miles since I swapped out the switch and no issues so far. I think the anchor bolt is fine when torqued at 18lbs same as the switch.

While poking around looking for leaks I did notice that it looks possible to get a 17mm wrench around the anchor bolt without removing the alternator. There is a gap below the alternator above the block. If you had the right size wrench it may work. If nothing else give it a shot before you remove the alternator, it's free to try.

 

I don't know all the specs around the oil system, I'm sure there are after market sensors that can accomplish what your looking for, but i would be surprised if 15 psi didn't cause your switch to flicker in some scenarios, maybe shifting into neutral on the highway, or when the bypass in the filter closes. If that wound up being the case you would end up training yourself to ignore the oil pressure light altogether. Ultimately putting yourself in the same position of waiting to hear the knock knock that isn't even a little funny.

[ej25_TS]

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[awhitney1]

Any way to get a new Anchor? I kinda screwed mine up