[x5vo]

Hi, I have a 2021 BMW x5 xDrive40i with 32K miles on it. The car was getting its engine air filter replaced. When we looked into the hose that connects to the air filter box into the air intake, we noticed a film of oil on the inside of the house. Why would there be oil in the air intake and what could be causing it?

[swainbmw]

Originally Posted by x5vo

Hi, I have a 2021 BMW x5 xDrive40i with 32K miles on it. The car was getting its engine air filter replaced. When we looked into the hose that connects to the air filter box into the air intake, we noticed a film of oil on the inside of the house. Why would there be oil in the air intake and what could be causing it?

I replaced my intake and filter with the cold air intake from dinan and my car only had at the time about 8000 miles and it had oil in the tube Also, I would say it’s completely normal. I’m assuming it’s probably because there’s no catch can for the oil Vapors running through the PVC and back around that’s my assumption

[eelnoraa]

If where you look is after the MAF, it is normal. PCV value redirect crank case air/fume back to intake after MAF. This fume is basically oil vapor, gasoline vapor .... The entire intake path see this dirty fume. The eventually cause build up at back of intake values. Look up "direct injection intake buildup".

If you see oil before MAF, then there is a problem

[x5vo]

Thanks for you replies. I see the oil film after the MAF sensor inside the tube going to the intake. Is there a way to measure/diagnose this to see if the amount of oil is normal?