Need some advice , the engine consumes one quart of oil apr. every 300-350 miles , had a shop that is in business since 1977 ( specializing on BMW ) replace the external oil seperator and all the tubing at my request . Still no improvement , i did a conpression test on all 6 cylinders when i first noticed the consumption , cylinder #1 was at apr. 155 and the rest were at 160 , exhaust smoke is normal would have not bought car if i noticed oil burning exhaust . the engine is a 530 xi non turbo . My question is i have read that these engines due consume oil , 300-350 miles a quart normal ?

 

One quart every 350 miles definitely isn't normal, you have a leak or something else going on. Consider removing the shields under the engine - get a good look at the oil pan, joint between engine and transmission, front of the oil pan / front main seal area, and all aournd the head gasket. How many miles on the car? I assume you didn't find any oil around the spark plugs and injectors when you did the compression test. Good luck with this.

 

Thanks for the info. gman6262 , i have been under this car many times since i bought it no leaks , no oil stains on my driveway the car has 120,450 miles again thankyou for letting me know that 350 miles is not normal .

 

I wonder if some valve stem seals have gone. That'd be about the only place where you might lose oil without seeing it externally. Well that or a head gasket.

 

The E61 is known for having PCV issues that can result in high oil consumption. I'd look into that.

Jose

 

Thanks for your advice, I am afraid valve stem seals might be the problem i will just drive the car as is locallyy