DIY : Oil pressure switch

Replacing oil pressure switch P/N 12611710509 or 126175688480. Different numbers but same part. Should run you about 25 bucks at your local stealership.

Tools required: 10mm,12mm sockets, angled ratchet or socket extension, teflon tape or equivalent thread sealant, crescent wrench, 15/16 or 24mm open ended wrenches.

Depending on your mechanical inclination, it should take about 30 min to an hour to do the job.

On the diagram (from realoem.com), it shows the oil pressure switch as #12, next to the water/oil temp sensor (#13). On my vehicle, this diagram is misleading. I can't speak for other E46s out there but with mine, there is only a hex bolt in that location.

The oil pressure switch is actually located just underneath bolt #11. It is a single prong connection as opposed to the two prong connector used with the temp sensor. Initially, if you follow the diagram, it appears that the temp sensor is the oil pressure switch but IT IS NOT.



1) Completely remove air box. Loosen two 10mm bolts on the bottom and gently pull it out. I'll spare the detail. If you get caught up at this stage of the game, better hand it off to someone more qualified.

2) Remove two 12mm bolts holding the power steering reservoir. Gently set is aside.

3) With the air box and reservoir out of the way, getting to the switch will be much, much easier.



4) New switch with teflon tape, ready to install. I would HIGHLY RECOMMEND using some type of thread sealant.


Circled in YELLOW is the water/oil temp sensor. Note the two prong connection. Obviously, the connector harness has already been removed. Circled in RED is the location of the oil pressure switch. This was taken after the old one had been removed.


5) Remove wire connections to the sensor and pressure switch by squeezing the metal spring and gently pulling them off. You can leave the temp sensor connector on, but getting it out of the way helps a bit.

6) Getting the old switch loose is tricky. A deep well 15/16 or 24mm socket fits, but getting enough space to work with down there is a b#$ch. I rarely advocate the use of a crescent wrench, but in this case, it did the trick. I didn't have an open ended wrench big enough, but I would recommend it as the best option for removal of the switch. Mine was not super tight and came off fairly easily with the gentle caress that only a crescent wrench can provide.

7) Install new switch. Factory torque specs are 27nm. Again, getting a torque wrench to fit down there would be tricky. I hand tightened the switch and gave it about 3/4 of a turn until it was nice and snug. DO NOT OVERTIGHTEN!!!

Switch installed


8) Re-connect harness to switch and temp sensor, mount power steering reservoir and install air box. Be sure to check for any potential leaks after the car has been driven a bit and you should be good to go.



DISCLAIMER: I am not a professional mechanic;Follow this advice at your own discretion!!!!

My apologies to anyone reading this thread. I have accidentally deleted the photos and are unable to retrieve them. I am reposting the diagram from realoem.com as well as new photos in the hopes that it will be some help to anyone tackling this DIY. When I replaced the switch on my car, the diagram was a bit misleading. Perhaps some models are different, but I can only share my own experience here. According to the diagram below, the switch is located at #12 next to the water/oil temp sensor at #13. With my car, it IS NOT at this location. There is only a bolt there, but NO SWITCH. I found the switch to be located just underneath the hex bolt labeled #11. It's a single prong connector as opposed to the two prong connector used for the temp sensor. At first, it almost appears that the oil temp sensor is the oil pressure switch, but IT IS NOT.



With air box and power steering reservoir out of the way.


The thin red circle is the oil pressure sensor. To the left is the oil temp sensor.


Disconnect harness for oil temp sensor to get better access to the pressure sensor


Disconnect wiring harness from the pressure sensor and use a 15/16 or 24mm open end wrench and gently remove the sensor from the oil filter housing. Kind of a tight space in there, but manageable. Giggity.


Sensor removed. Note one prong connector.



Add a little thread sealant on your new sensor, making sure it has a new crush washer (included). The torque specs call for 27nm although I couldn't fit a torque wrench in there. I made sure it was snug against the housing and then tightened another quarter turn. Should do the trick.

Thank!

Thanks for the clarification on the missing photo's at least!

I'm about to tackle this DIY - can you tell me if I need to empty the oil beforehand? I'm guessing that I do not need to do so.

EDIT: For those interested, I found that the first 4 minutes of this youtube video were a great walkthrough of steps #1 - #3:

Yes. Change the oil as you are changing the oil pressure switch. The switch is on the bottom of the oil pan near the oil plug.

Originally Posted by longtran1

Yes. Change the oil as you are changing the oil pressure switch. The switch is on the bottom of the oil pan near the oil plug.

Thanks for the response!

Are you talking about the oil level sensor? I think that's the one on the bottom of the oil pan. I'm asking about the oil pressure switch, which appears to be located in the vicinity of the oil filter. I am hoping to sneak the DIY in without having to change the oil (since I just changed it 2K miles ago).

Sorry, I was talking about the oil level sensor on the bottom. I think it will be ok to change the oil pressure sensor without changing the oil. I would just suck out suck oil in the oil filter canister so it wouldn't be a mess.

No need to bother with anything oil related when changing the switch. There will be the slightest amount of oil that drips out when removing the switch but nothing major at all.

Added a few new pics in above post. Hope this helps some fellow members out there.

I "risked it" and didn't remove any oil, and like timothyfuqua said, there was only oil residue present. No issue there.

Now that it's been several weeks, I can safely say that changing the oil pressure switch successfully resolved my "blinking red oil light" issue!

Funny, while I was writing this post, timothyfuqua reposted some of his old pics! I'll just add one that I took. Despite the strong warning that the water/oil temp sensor could be easily be confused with the oil pressure switch, I still almost unscrewed the wrong thing. In the pic below, the oil pressure switch is circled in red, and the water/oil temp sensor is in yellow. You want to change out the RED one (which, by the way, seems to be less torqued than the yellow circled one)

Good job man! I hope the ominous blinking red oil light monster stays away ......

Thanks! Yeah, if it comes back, I'm pretty sure it's going to be more than a $20 fix. :-/

I don't seem to find a tremendous amount of data that would indicate the oil pressure switch as something that consistently fails but I can only share my experiences. I have performed this repair on several e46's with success. By success, I mean it cured the flickering red oil light problem. I have replaced my own twice in a four year period and in each instance, the flickering light disappeared. This could, by all accounts, be connected somehow to another, dare I say, bigger issue or it could just be that this sensor is more prone to failure/malfunction that a lot of e46 owners are aware of. Either way, that would be the first place I would look when the flickering red oil light monster visits you. I hope this helps fellow members in the future.

Thanks for the DIY. I just found this through the search function, and it helped out. I ordered a new switch preventatively. I didn't want to get caught somewhere far away from home wondering if a red oil light was due to the switch or a bigger problem.

Thank you so much for posting this, OP. I had a hard time removing the old switch: I started by using a crescent wrench and I almost stripped the bolt. Finally, I decided to run to Sears and I picked up a 15/16 open stub wrench and I was able to loosen it. The switch cost me $25 with tax at the Stealership. I just took the car for a test ride and the dreaded intermittent flashing red oil light did not turn on once.