[lazeer321]

Hi guys

I would like some suggestions on what could be some "common" problems regarding this issue with my car...

I have a E93 (320i), N46B20B engine; and the car is asking for +1L of oil every 200-300km

I have checked under the engine to see if there is some oil leak, but its always dry, no blue or white smoke coming from the exhaust either... I recently flushed the steering fluid and topped it up with CHF11S, i had to remove a large plastic cover under the car, no oil leak either..

The car is currently using FUCHS Titan GT1 Pro Flex 5W-30 oil.

Any advise is greatly welcomed
Thanks

[F31B48]

Worn valve stem seals are a very common cause of excess oil consumption with the N46 engine. Try this test. Get the engine up to operating temperature, leave it idling for 10 mins, then rev the engine up to 4000rpm and see if there is any smoke from the tailpipe.

[lazeer321]

Originally Posted by EvaBmw

Worn valve stem seals are a very common cause of excess oil consumption with the N46 engine. Try this test. Get the engine up to operating temperature, leave it idling for 10 mins, then rev the engine up to 4000rpm and see if there is any smoke from the tailpipe.

Thanks for answering @EvaBmw, i drove the car for a while until i got it to operating temp, rev'd it up to 4-5k rpm, and there was no sign of any type of smoke coming out from the tailpipe....so i'm assuming the valve stem seals are not the problem? Please correct me if i'm wrong

[TheMidnightNarwhal]

Originally Posted by lazeer321

Thanks for answering @EvaBmw, i drove the car for a while until i got it to operating temp, rev'd it up to 4-5k rpm, and there was no sign of any type of smoke coming out from the tailpipe....so i'm assuming the valve stem seals are not the problem? Please correct me if i'm wrong

Did you idle it for 10 mins, then rev it?

[lazeer321]

Originally Posted by TheMidnightNarwhal

Did you idle it for 10 mins, then rev it?

Yes i did, i drove it for a while, then parked the car; waited a bit and then i rev'd it up.

[C4maro]

Damn thats a lot of oil in 200km to not be able to see it

[F31B48]

When you say waited a bit, was it 10 mins? It has to be at least 10 mins

[TheMidnightNarwhal]

Originally Posted by lazeer321

Yes i did, i drove it for a while, then parked the car; waited a bit and then i rev'd it up.

Are you sure there's nothing out the tailpipe? Oil has got to be burning.

[F31B48]

The other possibility is a faulty oil level sensor. The only way to confirm that though is draining and measuring the engine oil.
The correct amount for the n46 is 4.25 litres.

[mainbearing]

How do the spark plugs look? With that much oil consumption, the plugs should show some oil coating too (wet black look) I would think. And agreed, the exhaust should show some signs of oil coating too?

How about the valve cover area, is oil seeping out on top of the engine anywhere? Oil filler cap maybe?

[lazeer321]

Originally Posted by EvaBmw

Worn valve stem seals are a very common cause of excess oil consumption with the N46 engine. Try this test. Get the engine up to operating temperature, leave it idling for 10 mins, then rev the engine up to 4000rpm and see if there is any smoke from the tailpipe.

Update: I did the test again, drove the car for a while, parked it, waited 10-15 mins and rev'd it up, smoke came out of the tailpipe. My apologies for making the test in a wrong way. I attached a video showing what came out.
https://youtu.be/vJfxxOZCu1w

[TheMidnightNarwhal]

Originally Posted by lazeer321

Update: I did the test again, drove the car for a while, parked it, waited 10-15 mins and rev'd it up, smoke came out of the tailpipe. My apologies for making the test in a wrong way. I attached a video showing what came out.
https://youtu.be/vJfxxOZCu1w

Oh yeah there it is. If you take whiff does it smell like burned oil?

[lazeer321]

Originally Posted by TheMidnightNarwhal

Oh yeah there it is. If you take whiff does it smell like burned oil?

Yes it does, in this case, what should i be looking at as the source of the problem?

[F31B48]

Firstly check the pcv valve and hoses and make sure they are not blocked or split. If it's not that it will be the valve stem seals.

[lazeer321]

Originally Posted by EvaBmw

Firstly check the pcv valve and hoses and make sure they are not blocked or split. If it's not that it will be the valve stem seals.

Will do, i googled how to diagnose a bad pcv valve, and it said that when removing the oil filler cap while idling, there would be a strong suction in it as well as stumbling...i made the test and while there was no a strong suction, there was a rattling sound when lifting it.

Here is a video i made to test it: pcv test
I suppose that the rattling sound when it is lifted means that the valve is failing?