[6Inarowmakesitgo!]

Finally changed my oil separator last week and it definitely was the original part from the factory, having covered 200,000 miles. Since it has been changed I have noticed oil level remains at full (did an oil change at the same time I replaced separator) and it has been 1500 miles. I would usually notice it start to dip in level at this point.

Out of curiosity I cut mine open and found it to have about 1/8” of cooked on sludge all over the interior and the diaphragm had a significant wear spot over the center portion were it is supposed to seal the port going to intake manifold. The heating element was also blown too, and it being nice and cold here in Wisconsin surely did not help oil consumption.

Has anyone had success with this curing their oil consumption issues? Also when I had it apart, I checked the oil return tube, the one that threads into the engine block, and noticed it is just a straight tube and no internal components. I had read that this was supposed to have a check valve/ball in it, is that correct? It’s interesting to note, this connects to the bottom of the separator and travels straight to the port where the intake manifold is connected to, and the cyclonic portion empties out in the middle between the two.

[TunafishE93]

What was your oil change intervals?

[6Inarowmakesitgo!]

Originally Posted by TunafishE93

What was your oil change intervals?

Original owner did 7000-7500 mile intervals from new with BMW oil during warranty period then Pentosin after the warranty period and always with a MANN filter. I purchased the vehicle at 165,000 miles and I do 5000 mile intervals with liqui moly 5W30.

Inside the valve cover is quite clean and it runs silky smooth. No smoke on startup or deceleration either and plugs do not have any ashy deposits.

[Efthreeoh]

I'm the original owner of my car, which is a 2006 E90 325i. I ordered it in April 2006 and it was delivered in May 2006 with just 3 miles on the odometer. Outside of just a few things and BMW's joke of "free" maintenance, I've performed all the service on the vehicle as DIY.

When my engine reached 200,000 miles back in January 2013 it did not have any appreciable oil consumption. My average OCI at 200,000 miles was 16,300 miles. Around 230,000 miles is when the engine started consuming oil, which started as about a quart every 12,000 miles or so. Over time oil consumption digressed to about 1,800 miles per liter at 382,000 miles. That was November 2019. The only oil ever used in my engine has been BMW 5W-30 LL-01 and MANN HU-816 filters since the first oil change at 17,640. It did need it's first quart of oil at 17,095 miles. Since 230,000 miles, the OCI is mileage based (vs. CBS-based) at 10,000 miles.

I replaced the entire CCV system and cleaned the intake manifold in early November 2019 at 383,000 miles. Valve stems and tops were clean, dry, and slightly brown. There was a very small amount of black carbon deposits on the very top of the intake ports in the cylinderhead. The engine oil level was not at the full mark as it had about 5,000 miles on the current oil compliment in the oil sump. Since I changed the CCV I added 1 liter of oil at 384,900, which got the engine back to full (showing a 1,900 mile/liter consumption rate after the CCV change). Since then I added 1 additional liter 387,250, indicating a 2,300-mile/liter consumption rate. So the oil consumption has not improved much, but the engine idles much better and runs very well. The average MPG has stayed within 1-MPG average over the 387,000-mile life of the engine (I've kept records of every fuel refill and MPG since day one), which is an indication the engine is still making good power. The engine exhaust does not smoke and the inside of exhaust tips are dry with some soot, which is normal. There is no black oily residue on the back of the car, like you see on real oil burners. I'm guessing the oil rings are not fresh or the valve stem seals are worn and passing oil. But the oil consumption is still within BMW spec.

I was hoping for a dramatic oil consumption rate decrease with installation of the new CCV, but early data shows that probably is not the case.

[6Inarowmakesitgo!]

Originally Posted by Efthreeoh

I'm the original owner of my car, which is a 2006 E90 325i. I ordered it in April 2006 and it was delivered in May 2006 with just 3 miles on the odometer. Outside of just a few things and BMW's joke of "free" maintenance, I've performed all the service on the vehicle as DIY.

When my engine reached 200,000 miles back in January 2013 it did not have any appreciable oil consumption. My average OCI at 200,000 miles was 16,300 miles. Around 230,000 miles is when the engine started consuming oil, which started as about a quart every 12,000 miles or so. Over time oil consumption digressed to about 1,800 miles per liter at 382,000 miles. That was November 2019. The only oil ever used in my engine has been BMW 5W-30 LL-01 and MANN HU-816 filters since the first oil change at 17,640. It did need it's first quart of oil at 17,095 miles. Since 230,000 miles, the OCI is mileage based (vs. CBS-based) at 10,000 miles.

I replaced the entire CCV system and cleaned the intake manifold in early November 2019 at 383,000 miles. Valve stems and tops were clean, dry, and slightly brown. There was a very small amount of black carbon deposits on the very top of the intake ports in the cylinderhead. The engine oil level was not at the full mark as it had about 5,000 miles on the current oil compliment in the oil sump. Since I changed the CCV I added 1 liter of oil at 384,900, which got the engine back to full (showing a 1,900 mile/liter consumption rate after the CCV change). Since then I added 1 additional liter 387,250, indicating a 2,300-mile/liter consumption rate. So the oil consumption has not improved much, but the engine idles much better and runs very well. The average MPG has stayed within 1-MPG average over the 387,000-mile life of the engine (I've kept records of every fuel refill and MPG since day one), which is an indication the engine is still making good power. The engine exhaust does not smoke and the inside of exhaust tips are dry with some soot, which is normal. There is no black oily residue on the back of the car, like you see on real oil burners. I'm guessing the oil rings are not fresh or the valve stem seals are worn and passing oil. But the oil consumption is still within BMW spec.

I was hoping for a dramatic oil consumption rate decrease with installation of the new CCV, but early data shows that probably is not the case.

That’s impressive. I guess I will have to wait and see how it effects consumption. My compression and leak down tests were excellent as well, so probably not the rings, maybe valve stem seals like you mentioned. All of my intake ports were spotless, but when I had the manifold removed a decent amount of oil drained out of the #6 intake runner.

Mine is a 330xi, October of 2005 build date.

I do have an oil pan gasket leak, but it’s definitely not the cause of such high consumption. It doesn’t leave spots anywhere I park, even after sitting for a week at times.

[PhaseP]

Originally Posted by 6Inarowmakesitgo!

Has anyone had success with this curing their oil consumption issues? Also when I had it apart, I checked the oil return tube, the one that threads into the engine block, and noticed it is just a straight tube and no internal components. I had read that this was supposed to have a check valve/ball in it, is that correct? It’s interesting to note, this connects to the bottom of the separator and travels straight to the port where the intake manifold is connected to, and the cyclonic portion empties out in the middle between the two.

This is where the ball operated check valve is, it is integrated into the connector part. If you shake it you will hear rattle of the ball, if it is clean that is. :

[6Inarowmakesitgo!]

Originally Posted by PhaseP

This is where the ball operated check valve is, it is integrated into the connector part. If you shake it you will hear rattle of the ball, if it is clean that is. :

Ahhh, I see.

That hose was replaced! So all is well. Thank you.