535i (N55) oil temp lower than normal

[Gad-Westy]

2011 F11 535i. I noticed yesterday that oil temperature on a 50 mile journey never got much above 1/4 on the gauge. 85-90 deg C. Same on my return journey. It normally sits bang in the middle of gauge at 120 deg C once warmed up. How normal is this? If it were a water temperature gauge and was stuck a quarter of the way up, I'd be suspecting the stat is stuck open but I'm aware these modern BMW turbos can do clever things with engine temps to control emissions so I don't want to blindly assume I have a problem. Anyone got any thoughts?

[Court_S]

Obviously not the same engine, but I found that the oil temps of my N54 fluctuated loads, particularly on cooler days and fairly gentle journeys at motorway speeds.

[Gad-Westy]

Court_S said:

Obviously not the same engine, but I found that the oil temps of my N54 fluctuated loads, particularly on cooler days and fairly gentle journeys at motorway speeds.

Cheers Sam. Something for me to keep an eye on. I'll get the code reader on there too in the next day or two.

[steve_n]

I've got the same car, same year. It always heats up to just under the 125 mark and stays there. Yours has a problem which is probably a stuck open water thermostat because the coolant is being allowed to cool the oil too much. Time to get it changed pronto.

[jv021]

I had a 640i with the N55 and the oil never fluctuated once up to temp. The needle was always in the middle regardless of how it was driven, ambient temp etc etc.

if anything i thought the engine ran a little hot as after a longish drive you could feel the heat from the front of the car.

[Pica-Pica]

jv021 said:

I had a 640i with the N55 and the oil never fluctuated once up to temp. The needle was always in the middle regardless of how it was driven, ambient temp etc etc.

if anything i thought the engine ran a little hot as after a longish drive you could feel the heat from the front of the car.

I would prefer that to be ‘the needle never fluctuated once up to the middle position’. It is quite likely that there may be some variation in the actual temperature, but as long as this is controlled and brought back down (or up) the driver does not need to know. I imagine the indication is kept at a central point except when warming up or when there is a sustained deviation from the accepted temperature range.
I am not saying that there is nothing wrong with OP’s car, just that gauges are meant to inform without worrying the driver.

[steve_n]

I have MHD so can log what the car is doing. The oil temperature is consistently around 110, within a few degrees either way.

[Gad-Westy]

steve_n said:

I've got the same car, same year. It always heats up to just under the 125 mark and stays there. Yours has a problem which is probably a stuck open water thermostat because the coolant is being allowed to cool the oil too much. Time to get it changed pronto.

Something strange going on. I used it today and checked some readings

Coolant temp is normal but oil temperature is low.

Do these cars have any stat control for oil cooling or any other way of controlling oil temp independently of coolant? Or maybe I have a bad oil temp sensor? No error codes though.

[d_a_n1979]

Gad-Westy said:

steve_n said:

I've got the same car, same year. It always heats up to just under the 125 mark and stays there. Yours has a problem which is probably a stuck open water thermostat because the coolant is being allowed to cool the oil too much. Time to get it changed pronto.

Something strange going on. I used it today and checked some readings

Coolant temp is normal but oil temperature is low.

Do these cars have any stat control for oil cooling or any other way of controlling oil temp independently of coolant? Or maybe I have a bad oil temp sensor? No error codes though.

Looks like it could be pointing to a failed oil sensor:

https://www.e90post.com/forums/showthread.php?t=19...

[Gad-Westy]

d_a_n1979 said:

Looks like it could be pointing to a failed oil sensor:

https://www.e90post.com/forums/showthread.php?t=19...

Having looked at how much of a pig of a job the temp sensor looks (buried under inlet manifold) and how relatively simple replacing the oil stat is (front top of engine) and the lack of codes saying what my issues is and that the oil temp read out is steady but low, I think I'm going to replace the oil stat first and then the temp sensor if that doesn't fix it. I haven't got a price for the stat yet. All the google results are for aftermarket low temp stats. I'll figure out some part numbers and phone the dealer.

[d_a_n1979]

Gad-Westy said:

d_a_n1979 said:

Looks like it could be pointing to a failed oil sensor:

https://www.e90post.com/forums/showthread.php?t=19...

Having looked at how much of a pig of a job the temp sensor looks (buried under inlet manifold) and how relatively simple replacing the oil stat is (front top of engine) and the lack of codes saying what my issues is and that the oil temp read out is steady but low, I think I'm going to replace the oil stat first and then the temp sensor if that doesn't fix it. I haven't got a price for the stat yet. All the google results are for aftermarket low temp stats. I'll figure out some part numbers and phone the dealer.

This one?

https://shop.bmw.co.uk/6783/genuine-oil-pressure-s...

[Gad-Westy]

d_a_n1979 said:

Gad-Westy said:

d_a_n1979 said:

Looks like it could be pointing to a failed oil sensor:

https://www.e90post.com/forums/showthread.php?t=19...

Having looked at how much of a pig of a job the temp sensor looks (buried under inlet manifold) and how relatively simple replacing the oil stat is (front top of engine) and the lack of codes saying what my issues is and that the oil temp read out is steady but low, I think I'm going to replace the oil stat first and then the temp sensor if that doesn't fix it. I haven't got a price for the stat yet. All the google results are for aftermarket low temp stats. I'll figure out some part numbers and phone the dealer.

This one?

https://shop.bmw.co.uk/6783/genuine-oil-pressure-s...

That's pressure I think.

[d_a_n1979]

Gad-Westy said:

d_a_n1979 said:

Gad-Westy said:

d_a_n1979 said:

Looks like it could be pointing to a failed oil sensor:

https://www.e90post.com/forums/showthread.php?t=19...

Having looked at how much of a pig of a job the temp sensor looks (buried under inlet manifold) and how relatively simple replacing the oil stat is (front top of engine) and the lack of codes saying what my issues is and that the oil temp read out is steady but low, I think I'm going to replace the oil stat first and then the temp sensor if that doesn't fix it. I haven't got a price for the stat yet. All the google results are for aftermarket low temp stats. I'll figure out some part numbers and phone the dealer.

This one?

https://shop.bmw.co.uk/6783/genuine-oil-pressure-s...

That's pressure I think.

Ah yeah sorry!

Just looking on RealOEM; I can see the housing but not the stat - as you said everything online seems to point to aftermarket

ie: https://www.evolveautomotive.co.uk/products/mossel...

[Gad-Westy]

d_a_n1979 said:

Gad-Westy said:

d_a_n1979 said:

Gad-Westy said:

d_a_n1979 said:

Looks like it could be pointing to a failed oil sensor:

https://www.e90post.com/forums/showthread.php?t=19...

Having looked at how much of a pig of a job the temp sensor looks (buried under inlet manifold) and how relatively simple replacing the oil stat is (front top of engine) and the lack of codes saying what my issues is and that the oil temp read out is steady but low, I think I'm going to replace the oil stat first and then the temp sensor if that doesn't fix it. I haven't got a price for the stat yet. All the google results are for aftermarket low temp stats. I'll figure out some part numbers and phone the dealer.

This one?

https://shop.bmw.co.uk/6783/genuine-oil-pressure-s...

That's pressure I think.

Ah yeah sorry!

Just looking on RealOEM; I can see the housing but not the stat - as you said everything online seems to point to aftermarket

ie: https://www.evolveautomotive.co.uk/products/mossel...

Yeah, I'm finding it incredibly difficult to find good information on this. On an N54 the lump attached to the front of the oil filter housing incorporates a thermostat or maybe only is the thermostat. On the N55, or at least my N55, the lump on the front is a finned housing that looks much more like a cooler. And indeed, realOEM describes it as a heat exchanger, no mention of a stat but maybe there is something hiding inside.

But if I look at all the aftermarket stuff available, they look like the N54 housing even when it's described as being or an N55 so I'm wondering if 1-series and 3-series N55 cars may have a different oil cooler set up. Or maybe it's an auto vs manual thing.

This is my housing:

|https://forums-images.pistonheads.com/65571/202404233985546[/url]

Looks to be leaking a bit as well so might be a good time to replace all the gaskets in that area.

It looks to match the Real OEM set up.



Auotdoc have Febi Bilstein (and others) for not too crazy a price but I cannot find anything to confirm that there is some temperature control going on inside and not just a heat exchanger.
https://www.autodoc.co.uk/febi-bilstein/8767222[ur...

Edited by Gad-Westy on Tuesday 23 April 14:01

[Gad-Westy]

Getting somewhere now.

My car is an SE, not MSport. Reading this discussion suggests that my car probably only has the oil cooler next to the filter and not a separate remote cooler so that explains the differences seen between models.

https://f10.5post.com/forums/showthread.php?p=3065...

But I'm still not actually sure if there is an oil thermostat in there as well or whether that is elsewhere or if it doesn't exist at all on my car.

I assume 90 deg C is a normal coolant temp for my car? I only ask because if my car doesn't have an oil thermostat, then the only thing controlling oil temperature is coolant temperature. 90 seems normal to me for a car but I've never checked this car before I noticed the oil temp being low.

To me if there is no separate oil thermostat it can really only be that the coolant temp is also lower than normal or that the oil temp sensor is under reading.

Edited by Gad-Westy on Tuesday 23 April 14:03

[Gad-Westy]

I found this image of the filter housing online.

Anyone able to confirm what the component in the bottom left is? I'm assuming it's not an oil thermostat because the filter housing part number seems to be shared with cars that have the separate stat housing but thought I better ask.

[Gad-Westy]

Would any kind heated N55 owner check what their coolant temperature is in normal warmed up state?

I'm starting to think that 90 deg C is actually cool for this engine and I should be higher. If so, that would point to the coolant thermostat after all. No error code though.

[steve_n]

Coolant should be 100-105 degrees consistently when warm. As I said earlier, I suspect the coolant thermostat is stuck open.

Definitely get the oil filter housing gaskets replaced. If left, the auxiliary belt can slide off and get ingested in the engine. Make sure the oil pump is primed several times afterwards, or risk bearing failure like on mine and someone else on here. There's a good write up on the 5 forum.

[Gad-Westy]

steve_n said:

Coolant should be 100-105 degrees consistently when warm. As I said earlier, I suspect the coolant thermostat is stuck open.

Definitely get the oil filter housing gaskets replaced. If left, the auxiliary belt can slide off and get ingested in the engine. Make sure the oil pump is primed several times afterwards, or risk bearing failure like on mine and someone else on here. There's a good write up on the 5 forum.

Thanks steve_n. I guess I'd been cautious to dive in and do the coolant stat just because A, it looks like a pain and B I thought my coolant temperature was normal. It seems that these engines run much hotter than I'm accustomed too so it does indeed seem I need to just dive in and sort the stat. I actually think I might do water pump, belts, tensioner, etc while in there. And as you say, the oil cooler gasket needs to doing. Noted on the priming. When you say several times, do you just mean turned over several times? On the F10/11 is it best to remove the injector connectors or is there a quicker method?

I have an engine oil change and gearbox oil change to do as well. Going to be busy!

[steve_n]

Get yourself signed up here, lots of good tutorial content from Andrew.

https://www.forum5.co.uk/topic/2145-f10-535i-n55-d...

https://www.forum5.co.uk/topic/15-f10-535i-diy-aux...