[jaywhituk]

Evening all,

I’ve got a 2007 E91 Petrol 318i and recently had the oil level flag as ‘INACTIVE’.
It seems to be a bit intermittent, but thought I best get the sensor swapped.

Today I contacted my normal mechanic and he’s said the new sensors is approx. £142 from his supplier.

I don’t cut corners, but curious if anyone has got experience of the cheaper sensors available at online stores?

Thanks..

[lowrydr310]

Your oil sensor might not be bad. The oil level sensor is one of four devices that share the Bit Serial Device (BSD) bus to communicate, the other three being the alternator, water pump, and intelligent battery sensor. If one item is faulty, it could take the whole bus down.

Do you have ISTA software? There's a diagnostics procedure that monitors the bus status in real time, and you disconnect the 4 devices on the bus one by one to determine the faulty component.

I had the INACTIVE oil level display once which was caused by a failing water pump. The pump itself worked fine but had an electronics issue that caused the BSD bus error. Replacing the pump restored function of the BSD bus and the oil level sensor was working again.

[StradaRedlands]

Originally Posted by lowrydr310

Your oil sensor might not be bad. The oil level sensor is one of four devices that share the Bit Serial Device (BSD) bus to communicate, the other three being the alternator, water pump, and intelligent battery sensor. If one item is faulty, it could take the whole bus down.

Do you have ISTA software? There's a diagnostics procedure that monitors the bus status in real time, and you disconnect the 4 devices on the bus one by one to determine the faulty component.

I had the INACTIVE oil level display once which was caused by a failing water pump. The pump itself worked fine but had an electronics issue that caused the BSD bus error. Replacing the pump restored function of the BSD bus and the oil level sensor was working again.

Yes, definite possible BSD problem. Ask me how I know... :-/

[ppointer]

Originally Posted by jaywhituk

Evening all,

I’ve got a 2007 E91 Petrol 318i and recently had the oil level flag as ‘INACTIVE’.
It seems to be a bit intermittent, but thought I best get the sensor swapped.

Today I contacted my normal mechanic and he’s said the new sensors is approx. £142 from his supplier.

I don’t cut corners, but curious if anyone has got experience of the cheaper sensors available at online stores?

Thanks..

My e91 has the N52. When the dash said low oil pressure, I located the sensor. Noticed it had a slight oil drip from it, so I purchased a replacement from FCP. Cost was less than $10 and took about ten minutes to replace. May be a poor comparison since the N52 is way different from your inline four cylinder.

[lowrydr310]

Originally Posted by ppointer

My e91 has the N52. When the dash said low oil pressure, I located the sensor. Noticed it had a slight oil drip from it, so I purchased a replacement from FCP. Cost was less than $10 and took about ten minutes to replace. May be a poor comparison since the N52 is way different from your inline four cylinder.

Low oil pressure? The oil level sensor doesn't have anything to do with measuring oil pressure, just the level of oil in the pan.

[ppointer]

Originally Posted by lowrydr310

Low oil pressure? The oil level sensor doesn't have anything to do with measuring oil pressure, just the level of oil in the pan.

"...the dash said low oil pressure, I located the sensor..." Who said anything about oil level sensor?

[lowrydr310]

Originally Posted by ppointer

"...the dash said low oil pressure, I located the sensor..." Who said anything about oil level sensor?

The guy who started this post, he said his oil level sensor was reporting INACTIVE.

What oil pressure sensor did you replace for $10? I'm not aware of any leaky oil pressure sensor on the N52.

[ppointer]

Originally Posted by lowrydr310

The guy who started this post, he said his oil level sensor was reporting INACTIVE.

What oil pressure sensor did you replace for $10? I'm not aware of any leaky oil pressure sensor on the N52.

Here you go. It was only $4.81 when I got it last year, but gone up a bit since then. What happened was I got a low oil pressure warning while sitting at a light in about 92F temps. I left it in a parking lot and Ubered on. Drove it home the next day with no more warning. Took a guess on the sensor because it was an oily mess. No more warning since the replacement (and now daughter has the car).

I don't have our other N52 handy at the moment as we're out of state, so I can't take a pic for you. But it is right in front more on the driver's side, right next to the oil filter housing.

Here is the link: https://www.fcpeuro.com/products/bmw...ch-12611710509