Decided to break up my previous post to cover a bit more detail on the BMW S54 oil pan and dual pick-up pump conversion for S50/S52 engines. This is very simple upgrade to the S50 and S52 (USDM) engines. The Euro-spec engines all came with these dual pick-up sumps. Most of this information came from this thread on Bimmerforums.com.
Here’s the complete parts list (see RealOEM pan and pump):
(1) S54 Oil Pan – Part # 11-13-7-838-130
(1) S54 Oil Pump – Part # 11-41-1-405-123
(1) S52 Oil Pump Sprocket – Part # 11-41-1-719-935
(1) Oil Pump Nut – Part # 07-11-9-905-857
(1) Oil Pan Gasket – Part # 11-13-1-437-237
(1) S54 Dipstick Tube – Part # 11-43-7-832-140
(1) S54 Dipstick – Part # 11-43-7-831-140
(1) Dipstick Flat Washer – Part # 11-43-7-838-127
(1) Dipstick O-Ring – Part # 11-43-1-707-164
(1) Dipstick Bracket – Part # 11-43-7-500-374
(1) Dipstick Bracket Hex Nut – Part # 07-11-9-905-534
(1) Bracket Oil Pipe – Part # 11-41-1-405-847
(1) Bracket Oil Pipe – Part # 11-41-1-404-645
(1) Return Pipe – Part # 11-41-7-834-889
(1) Suction Pipe – Part # 11-41-7-834-887
(1) O-Ring – Part # 11-41-1-401-769
(2) Fillister Head Bolt – Part # 07-12-9-903-041
(1) Cover – Part # 11-13-7-834-885
(1) Gasket – Part # 11-13-7-834-886
(8) Hex Bolt w/ Washer – Part # 07-11-9-904-524
(1) E36 Cover Lid (replaces Oil Level Sensor) – Part # 11-13-1-726-357
(1) Gasket Ring – Part # 12-61-1-277-129
(3) M6x25 Hex Bolt – Part # 01-11-9-905-400
Bimmerworld also offers a complete kit for both OBD I and II here.
I saved a lot of money by buying a pan from a junkyard, which included the dipstick, the strainer, and several other bits. You can also save on the various bolts, which are mostly common M6x1.0 and can be found at the hardware store (or if you’re like me you have tons of spares laying around.) The pan was cheap because it had a small crack, which was easily fixed with $20 weld job.
The engine came with a VAC Motorsports baffle kit installed in the oil pan. Not a bad option by any means, but there is a better solution: S54 dual pickup pump and pan. I’ve already mentioned that the M50 family of engines can share a lot of parts, this is another benefit. The S54, unlike the S50US, is a true motorsports built engine. It came with a dual sump pan and two pickups, with a return pipe to pump extra oil to the main rear sump. Oil starvation is very uncommon on this engine, but a very real concern for the S50 (especially with its hydraulically actuated lifters.) The upgrade is basically plug and play, but requires using an S52 oil pump sprocket (the S54 has a larger tooth count to account for the higher revving engine.) The S50/52 windage tray also has to be scrapped, since the S54 scavenge/return pipes use two mounts off of the main bearing caps vs. the single mount of the S50/52. This shouldn’t be a huge deal since the S54 pan has somewhat of a windage tray cast into it.
A common issue with all M50 family oil pumps is the possibility of the oil pump sprocket nut backing off. This issue is exacerbated on the high-revving S54. Losing an oil pump sprocket would lead to near instant catastrophic engine failure. There are multiple solutions to this problem: 1. Welding the nut on, 2. Safety wiring the nut, 3. Staking the nut using a punch, 4. VAC kit. My M Coupe had its nut installed with Red Loctite and staked into place by Randy Forbes. The S50 I bought came with the VAC kit, which replaces the splined pump shaft with a keyed shaft and bolt. This kit isn’t available for the S54 pump, to my knowledge, so I installed the sprocket on the S54 pump with a drilled nut and safety wire. In the photo on the left below you can see the keyed VAC sprocket and the splined OE sprocket. On the right you can see the S52 sprocket installed on the S54 pump with lock-wired nut. And no that isn’t a negative safety, it’s left-hand threads.
I ran into a small issue when installing the pan, stripping the threads from the rear of the main seal plate. Note: don’t use a cordless impact driver (even a low-torque one) to run bolts into aluminum. A quick Helicoil repair gave me some new M6x1.0 threads. I then installed the junk yard oil pan using a new gasket with some red Toyota FIPG (probably the best sealant) at the corners where the timing chain cover and main seal cover meet the iron block.
All of the pan bolts are reused except for three, which you’ll need to replace with longer M6x1.0x30mm to go through a slightly thicker casting in the S54 pan’s lip. I picked these up at the local Ace hardware.
The S54 pan uses an oil level sensor, which there is no provision for in the S50/52 wiring or chassis harness. Fortunately BMW makes a block-off plate for this hole. You can see the plate and gasket on the photo to the left below. My used pan came with the scavenge strainer already installed, but I went ahead and preemptively replaced the gasket.
I still have a few other items to take care of. The dipstick should be pretty straight forward. There is a small AN fitting on the bottom of the pan that needs a plug and then there is the crank vent drain. I’m contemplating running a oil catch can off of the head, then having it drain back to the pan with a check valve so I can still run vacuum from the intake.
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