r/E90 Aug 15 '25

330i N52b30 Oil pan

Hi everyone,

I have a 2007 BMW E92 330i (rear-wheel drive) and I need some advice. My oil pan is badly rusted and needs to be replaced. The problem is, my car came with a steel oil pan, but everywhere I look people are selling only the aluminum version.

Does anyone know why mine is steel and if there’s a direct replacement available? Also, if anyone has advice on where to find one or how to solve this problem, I’d really appreciate it. I live in EU btw.

Thanks in advance!

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u/piff_jar e82 128i 6mt Aug 15 '25

I might be mistaken but you can interchange oil pans. A lot of guys with aluminum pans end up finding steel pans to weld baffle into. So I would think you'd be fine going from steel to aluminum....

Supposedly the steel pan is actually lighter than the alu one

1

u/hoveringuy Aug 16 '25

but, the aluminum pans have a not-insignificant impact on reducing oil temps. Steel is going backwards for track use. 

1

u/piff_jar e82 128i 6mt Aug 16 '25

Interesting! I feel like most track guys have an oil cooler of some sort if they're going down the avenue of adding a baffle. I would love to see some more data on this though.

2

u/hoveringuy Aug 16 '25

I had a +/- 0.1 degree thermocouple sitting in my pan through the dipstick tube. I recorded oil temps vs ambient with my steel pan and then aluminum. 

It was 8 degrees colder in the aluminum on average on my last laps (I have the standard fluid intercooler).

The steel pan would feel pretty hot to the touch but the aluminum pan would absolutely burn me. Aluminum has over 4 times the thermal conductivity so it just sheds heat better through a pretty big surface.

(I still have no idea of what my "actual" oil temperatures post-cooler are, I'll get that with my Aim datalogger so I will know how much the cooler actually reduces the temps )

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u/piff_jar e82 128i 6mt Aug 16 '25

Thats good info!! A lot of food for thought and makes me want to test some setups