Can anyone give me a clear answer on what the oil operating temp on my 335i is suppose to be? I am running between 240-250 degrees and i feel that is a little high. Thanks.
A little high? What are you basing this on? First of all, don't confuse your oil temperature with your coolant temperature. These are two totally separate things. COOLANT is not supposed to get that hot, but for oil (which has a much hotter boiling point) this isn't a problem. I did some research on the web, and I actually found that 335i cars which have a valid oil temperature problem are doing closer to 280 to 300 degree oil temperatures. The car's computers are programmed to shut the car down around 320. You're nowhere near such a danger zone. Are you comparing this car to other twin turbo charged in-line sixes or naturally aspirated cars (these by nature tend to run cooler, but then that's the nature of a turbocharged vehicle to run hotter because of the way turbocharging works by compressing hot exhaust gases through a turbine impeller). You do have an oil temperature gauge. What is it telling you? If you were in the red zone and the gauge is working properly, the car would warn you. If your unfamiliarity with turbocharged vehicles makes you uncomfortable nonetheless, there are companies that sell secondary oil coolers. However, unless you are having a genuine oil temperature problem (and you don't seem to), I'd advise not creating a problem where none exists with unnecessary modifications to the oil system. Turbos, in the same way as your engine, do have a normal operating temperature, and must be allowed to reach them to perform properly.
Unfortunately the x35i cars do run higher oil temps then they should. Some BMW models have an OE oil cooler and others do not but should IMO. 240-250 F oil temp with synthetic oil is not a problem. 280 F is getting hot. The engine management system starts cutting power and accessories at 302 F. Up until that point BMW considers everything OK though most would prefer cooler temps.
Don't get a false sense of security though... If you see any unusual behavior, if temp gets around 280 or into the red zone, take it back to the dealer and stop driving it right away. As a precaution, have it towed on a flatbed if you can afford it. If not, just drive it very very carefully. Pull off the street or road if it gets hot on the way to the dealer, give it 30 minutes to an hour to cool down, then continue driving until it overheats again. It should still be under warranty.
what year is your 335? some of the earlier year models (like mine) came equipt with an oil temp guage where the normal operating temps would push it past the midpoint, giving it the appearance that its running hotter than normal. not sure what idiot at BMW did that, but all the models now have changed their guages fix this issue
I have a stett stage 2 oil cooler and my temps are around 220-230 at the absolute highest in 110+ heat. We also need to keep in mind your oil temp reading is nowhere near the actual temps as it is not in the middle of the crankcase.