Question about oil consumption on a high mileage m50b25

[runn3r]

So I have a 500k km m50 which has a weird oil consumption issue.

Sometimes the low engine oil shows up on the dash without the oil being even low? When the car is cold the low engine oil shows up the next time i park the car and check the oil it's fine for some reason and it's only missing a bit on the dipstick?

I also noticed oil on the bottom part of the intake hose could it be the rubber under the valve cover where the pcv connects (the metal plate that screws inside has a rubber gasket around it)? I've changed the PCV that connects to the valve cover (splits into 2 hoses the small one and the big one) there is a hose that goes to the dipstick does the oil go back in the dipstick or there shouldn't be any oil passing through these lines?

J80V9lE.jpg

Thanks.

[moroza]

The first is a sensor problem, not an oil problem. These sensors go bad once in a while - happened to my M60 at ~390Mm - and the solution is to either disable, replace, or clean/repair the sensor. I chose to disable mine.

The second... I had a hard time reading that. Punctation (, . ; - ! ? and so on) would help. It's normal for there to be a little oil in the intake, through the hose from the valvecover. Yours has a bit more than usual, but these engines don't have a proper crankcase ventilation system, and it's just what they do as they wear out.

[dennoz]

Just curious about something. Which hose is that that goes down to the dipstick?

I have a M52B28 OBD 1 swap in my E34 and also have a weird oil consumption to a point I have oil in the ICV, Mani, intake boot.....

Still figuring out what's up

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[runn3r]

The first is a sensor problem, not an oil problem. These sensors go bad once in a while - happened to my M60 at ~390Mm - and the solution is to either disable, replace, or clean/repair the sensor. I chose to disable mine.

The second... I had a hard time reading that. Punctation (, . ; - ! ? and so on) would help. It's normal for there to be a little oil in the intake, through the hose from the valvecover. Yours has a bit more than usual, but these engines don't have a proper crankcase ventilation system, and it's just what they do as they wear out.

Oh. Is the sensor level below the intake or is that the oil pressure sensor?

Yeah, my bad. You think the oil catch can would be a solution?

Just curious about something. Which hose is that that goes down to the dipstick?

I have a M52B28 OBD 1 swap in my E34 and also have a weird oil consumption to a point I have oil in the ICV, Mani, intake boot.....

Still figuring out what's up

Sent from my SM-N960U1 using Tapatalk

There are 2 hoses, the smaller one goes below the intake (on the boot that connects the ICV to the intake) and the bigger one goes to the dipstick, and then from the dipstick to the intake boot.

I don't know if people use the catch can, I feel like this is the engine to use it on.

There is a metal plate that goes in the valve cover and it has rubber gasket around it and i think that would be my issue and maybe yours too? The oil goes past the gasket and goes directly to the PCV?

OEM-ENGINE-CYLINDER-HEAD-VALVE-ROCKER-COVER-for-_57.jpg (2 philips screws hold the metal plate that i'm talking about)

[dennoz]

There are 2 hoses, the smaller one goes below the intake (on the boot that connects the ICV to the intake) and the bigger one goes to the dipstick, and then from the dipstick to the intake boot.

I don't know if people use the catch can, I feel like this is the engine to use it on.

There is a metal plate that goes in the valve cover and it has rubber gasket around it and i think that would be my issue and maybe yours too? The oil goes past the gasket and goes directly to the PCV?

OEM-ENGINE-CYLINDER-HEAD-VALVE-ROCKER-COVER-for-_57.jpg (2 philips screws hold the metal plate that i'm talking about)

Ah you mean the connector welded on dipstick support then towards the intake boot. Gotcha...

I use the plastic M52 valve cover

[runn3r]

Oh yeah I forgot how they went plastic fantastic on the m52..

HTB1S_6cXzLuK1Rjy0Fh760pdFXaW.png

[dennoz]

Oh yeah I forgot how they went plastic fantastic on the m52..

HTB1S_6cXzLuK1Rjy0Fh760pdFXaW.png

Now on the M52 they initially had the CCV setup. Did a delete and decided to use the M50 PCV setup. Modified a large rubber and connected the PCV valve.

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[moroza]

Catch can might help.

The oil pressure switch is a single 24mm M14 threaded plug in the oil filter housing. The oil level switch is a larger unit held in by 3x10mm M6 bolts in the lower part of the oilpan.