Thanks for the pictures showing N62 oil pressure switch location.
N62 Oil Pressure Switch Leaking

Drove mine up on some ramps, removed the front diaper (had to clean it anyway). Fit the socket on to the switch from underside of vehicle by using hoses and tubes as socket/extension support, loosened from top side. I didn't remove the coolant tank, but I did remove (2) vacuum pump large tube clamp nuts at vac pump and center front intake. I also disconnected the small vacuum tube at vacuum pump. This gives you a little wiggle room.

Installing it was somewhat of a challenge since getting your hands in there is really tight. I took small piece of paper towel and placed it over the 24mm socket business end, then inserted the replacement switch ensuring the paper was now creating a light press fit into socket opening keeping the switch in place against gravity. There was now enough stick-shun holding the switch in place, on the socket, to easily thread into place within restricted access.

Tool List:

3/8 long arm ratchet (swivel head helps)
3/8 3" Wobble Extension
10mm socket (for clamp nuts)
3/8 to 1/2 socket drive adapter
24MM 1/2 drive socket
Philips #2 Screwdriver (Diaper removal screws)
Paper towel / or tape to hold the switch on to the socket for installation purpose.
BWD Oil Pressure Switch $12.00 + tax (Oreilly Auto)

 

LOL

 

good write-up

 

If you don't have to remove the vacuum pump, do you just remove all of the hoses that run to and around the vacuum pump to gain access to the switch?

 

See now this would have been a hard diagnoses. Here's a good note though. I parked my car like a month or so ago on my slightly inclined driveway engine facing up. I haven't touched the car except starting it for 20 min every week. However, I didn't do this for 2 weeks. Sunday night i noticed a wet spot under the vehicle when pulling in and got under the car to examine. Pulled the vehicle forward and at least 1/2 liter was on the driveway. I touched it to see what it was. Sure enough it was my tranny fluid. I changed it 40K miles ago with Pentosin ATF+1 and guess what? STILL CLEAR! lol
Turns out the drain plug o-ring appears to be culprit. Didn't put it on the ramps to diagnose but im pretty sure that's what it is. On incline all the oil in the sump pan goes to the back. Sits there long enough and you can get some dripping. I noticed a few drips on incline and tightened the read pan bolts a bit more because that's where the seepage was coming from. Now apparently it's the drain plug. Tis what happens when a car is made of plastic. And i know it's not the same type of plastic/polymere used in the German firearms!

 

Did u fix ur oil leak was it the pressure switch ?

 

Did u change ur pressure switch ?

 

You own a 2004 545i which means it WILL have multiple oil leaks from multiple locations IF they have not been replaced in the past.

Your next best course of action is to take that VIN number and find out where the car has spent its life. Google, CARFAX, previous owner, etc.,

Now call the local BMW dealers in that area and find out if they ever replaced the various gaskets/seals on the engine. Give them the VIN and they will tell you what work has been done to the car at BMW dealerships.

Since your oil sensor was leaking; more than likely, the needed work has never been performed.

Yes, the oil sensor will leak, but trust me, you're at the tip of an iceberg on the 545.

There is plenty more where that comes from!

Start trying to find BMW certified technicians in your area that will replace the various oil leaks at a much reduced price.

If you're in Atlanta, I can steer you in the right direction.

 

Why do you ask where the car has spent its life? Is that to know what temperature extremes the car has been exposed to?

My 545i already had the vacuum pump leak, and while that was being replaced I had the oil switch done as well. I do know the other leak is the VCG. What are some of the others?

 

The reason it's important to know where the car spent its life is to narrow down shops it was worked at to get records on the car.

I did some digging on my 545i and found every maintenance record of the car since new. This is a good place to start as far as estimating oil leaks.

Other leaks likely coming up;

- valve cover gaskets
- upper timing chain cover gaskets
- alternator bracket gasket
- valve stem seals
- coolant valley return pipe gasket.

That's $6k worth of work - minimum.