[johnmyster]

So my car's oil drain has seen better days. Long story involving me trying to use a cheap magnetic drain plug and threads that had been abused to begin with. It's a 328 manual with the stamped steel pan. The oil pan gasket has always leaked and recently got worse, so it's time to pull it down anyway.

Cast aluminum "auto" pans are much easier to source, and have much deeper threaded sections for piece of mind. Does anyone see a reason a pan swap wouldn't work, assuming I used the right bolt kit. I can't see why the additional material/flanges at the rear would get in the way of the manual trans. Anyone know any different?

Other forum members have done transmission swaps (to manuals) without swapping oil pans, and it seems the 128 manual came with a cast aluminum pan. Worth picking one up for $100?

[Terraphantm]

Originally Posted by johnmyster

So my car's oil drain has seen better days. Long story involving me trying to use a cheap magnetic drain plug and threads that had been abused to begin with. It's a 328 manual with the stamped steel pan. The oil pan gasket has always leaked and recently got worse, so it's time to pull it down anyway.

Cast aluminum "auto" pans are much easier to source, and have much deeper threaded sections for piece of mind. Does anyone see a reason a pan swap wouldn't work, assuming I used the right bolt kit. I can't see why the additional material/flanges at the rear would get in the way of the manual trans. Anyone know any different?

Other forum members have done transmission swaps (to manuals) without swapping oil pans, and it seems the 128 manual came with a cast aluminum pan. Worth picking one up for $100?

I think it’ll fit fine. As you mentioned other N52 manuals come with the aluminum pan. I didn’t know about be 128, but the E60 525/528/530 came with the aluminum pan regardless of transmission. Your transmission actually has bolt holes that will line up with holes on the aluminum pan as well.

[W37V]

I think going with aluminum pan might be beneficial as steel pan tends to corrode (rust) around the oil sensor.

[Efthreeoh]

My oil pan recently started leaking at the oil sensor due to corrosion, so I dug into the part numbers for everyone's benefit. Note: this information is for RWD models only; 325xi and 328xi models use an entirely different oil pan due to the FWD drivetrain.

For the information posted below, the part numbers are from Realoem.com and pricing from GetBMWparts.com. There was a recent thread on this subject where a E90Post member did the steel-to-aluminum conversion to his 128i. It's not a straight bolt-on solution. The manual transmission version of the N52 has four (4) differences between it and the automatic transmission.

The four differences are:
-uses a steel oil pan version just for 2006
-uses a different steel oil pan for models MY 2007 and up (i.e. 328i vs. 325i)
-uses a different bell housing aluminum bolt set
-uses a different engine back cover sheet metal

I could not find anywhere on Realoem.com that indicates there is a version of the N52 used in any BMW with a manual transmission that came from the factory with an aluminum oil pan.

For converting from the steel oil pan to the aluminum oil pan on manual transmission cars, the engine backing plate, which is a thin sheet metal part, has two bolt locations on the bottom of the plate that have threaded bolt hole bungs. The bungs are thick steel inserts pressed into the backing plate sheet metal. This is a significant difference because two of the bell housing bolts at the bottom of bell housing either (A) thread into the oil pan and through holes in the engine backing plate for the auto trans, or (B) thread into the engine backing plate for the manual trans (and don't thread into the steel oil pan). The purpose of the bolts is really to just fix a bracket under the transmission that hold the electrical connectors for the to post-cat O2 sensors; they serve no structural connection between the transmission and engine block.

So to convert from a steel pan to the aluminum pan the threaded, thick bolt hole bungs are in the way of the rear of the aluminum oil pan, because the rear of the aluminum pan is thicker than the steel oil pan and snugs up to the bell housing. The options to solve this interference is to either (1) pull the manual transmission, clutch and flywheel and install the automatic trans version of the engine backing plate, or (2) cut out the steel bung inserts from the manual trans version of the backing plate. Option 2 does not require removal of the backing plate and makes the conversion far easier. The two bottom bell housing bolts are steel and are reused. According to Realoem they are the same bolts for either transmission.

Here are the associated part numbers. Note that the steel oil pan is different between the 325i (2006 model year only) and the 328i (2007 MY and up) because the crank case ventilation system is different between the model years 2006 and 2007 forward. The 2006 CCV has an oil drain return hose that attaches to a metal pipe welded onto the steel oil pan. The 2007 MY version of the steel oil pan is manufactured without the oil return pipe. If you are converting a 2006 model year car to an aluminum oil pan, you need to buy the steel oil return pipe and o-ring. If you are converting a 2007 and up model year car you need to buy the screw plug that seals the oil pan hole where the oil return pipe fits.

[Efthreeoh]

Originally Posted by W37V

I think going with aluminum pan might be beneficial as steel pan tends to corrode (rust) around the oil sensor.

I'm on the fence about it. It took my car 13 years to eventually leak at the oil level sensor. The pan prices are the same however. The aluminum pan drains from the side of the pan, where the steel pan drains straight out the bottom. In 2012 I replaced my oil level sensor and noticed rust around the opening, which I found amusing since its an OIL pan... Anyway, I wish I had the foresight back then to seal the crap out of the oil level seal with gasket sealer. If I had an E9X now and it wasn't rusted around the oil sensor opening, on the next oil change, I'd pull the oil level sensor, install a new gasket and apply a good amount of gasket sealer so it squeezes out around the top of the sensor base to prevent corrosion from creeping in. I'm afraid to do it now for fear that the sensor mounting studs will rip out of the rusted pan.

[Efthreeoh]

Originally Posted by johnmyster

So my car's oil drain has seen better days. Long story involving me trying to use a cheap magnetic drain plug and threads that had been abused to begin with. It's a 328 manual with the stamped steel pan. The oil pan gasket has always leaked and recently got worse, so it's time to pull it down anyway.

Cast aluminum "auto" pans are much easier to source, and have much deeper threaded sections for piece of mind. Does anyone see a reason a pan swap wouldn't work, assuming I used the right bolt kit. I can't see why the additional material/flanges at the rear would get in the way of the manual trans. Anyone know any different?

Other forum members have done transmission swaps (to manuals) without swapping oil pans, and it seems the 128 manual came with a cast aluminum pan. Worth picking one up for $100?

I checked the E87 130i (Europe only) and E88 128i, which use a N52N engine. Realoem shows both the E87 and E88 have a steel oil pan for the manual trans version of the car, P/N 11137553164

[Efthreeoh]

I found an aftermarket source at of all places Wally World...

[Terraphantm]

Originally Posted by Efthreeoh

I could not find anywhere on Realoem.com that indicates there is a version of the N52 used in any BMW with a manual transmission that came from the factory with an aluminum oil pan.

E60

[Efthreeoh]

Originally Posted by Terraphantm

E60

Thanks. I checked, the aluminum oil pan is the same part number for the N52 in the E60 with a manual trans as the N52 for the E9X aluminum pan with an automatic trans; P/N 11137552414. Interestingly the N52 engine rear cover plate (backing plate) are the same part two numbers as well for the manual version and the automatic version. The two bracket bolts are the same part number as well.

[W37V]

Originally Posted by Efthreeoh

I'm on the fence about it. It took my car 13 years to eventually leak at the oil level sensor. The pan prices are the same however. The aluminum pan drains from the side of the pan, where the steel pan drains straight out the bottom. In 2012 I replaced my oil level sensor and noticed rust around the opening, which I found amusing since its an OIL pan... Anyway, I wish I had the foresight back then to seal the crap out of the oil level seal with gasket sealer. If I had an E9X now and it wasn't rusted around the oil sensor opening, on the next oil change, I'd pull the oil level sensor, install a new gasket and apply a good amount of gasket sealer so it squeezes out around the top of the sensor base to prevent corrosion from creeping in. I'm afraid to do it now for fear that the sensor mounting studs will rip out of the rusted pan.

When I did my oil pan gasket few months ago, I noticed that there was surface corrosion around the sensor on mine as well. I am not even sure how it is corroding,as the whole freaking oil pan was covered with oil, but I guess that is chemistry.

[johnmyster]

Thanks. I've obtained said $100 aluminum used pan, gasket, and auto/aluminum bolt set. I'll post here after the swap. It'll be a few weeks.

If the worst I have to do is grind a threaded section from the engine backing plate, it'll be worth the difference. Used steel pans are hard to find (CCV drain or not) and $600+ new.

[W37V]

Originally Posted by johnmyster

Thanks. I've obtained said $100 aluminum used pan, gasket, and auto/aluminum bolt set. I'll post here after the swap. It'll be a few weeks.

If the worst I have to do is grind a threaded section from the engine backing plate, it'll be worth the difference. Used steel pans are hard to find (CCV drain or not) and $600+ new.

I think you can now run oil cooler rather easy as you will already have a hole tapped.

[mason_paul]

Hey, I just swapped my steel pan in my 2007 E91 to an aluminum one from eBay. Fits fine. Used tin snips to notch out the bosses near the trans and just flexed them until they broke. I’m happy with it and would totally do it again.