Three problems related to crankcase (pcv) have been reported for the 2015 Audi Q5. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2015 Audi Q5 based on all problems reported for the 2015 Q5.
Cylinder #3 lost compression, down to 30 psi from 170 psi, causing the car to lose power and run extremely rough or not run on occasion. This is a safety hazard, especially risky for highway driving. There were no warning messages, car just start running very rough or wouldn't start. Such loss of compression has been reported by an Audi service manager who says cylinder #3 is known to have this issue, but there is no recall for it yet. The problems began in may 2021. The car was drinking/consuming oil frequently and occasionally running rough. It was taken to multiple mechanics to identify the issue. Fixes included changing spark plugs, coils, and the pcv valve to provide temporary solutions at best. 5/24/21 increased consumption of oil began 9/9/22 rough idle, spark plugs replaced 10/14/22 rough idle and burning oil, taken to a service shop, replaced the pcv valve 7/12/23 rough idle again, spark plugs replaced again under warranty 2/14/24 - rough shake again, spark plugs replaced again and dead cylinder #3 confirmed.
SUV burns approximately 1qt oil per every 250-500 miles driven. Oil is accumulating on engine, causing burn and acrid odor. If I do not add a quart every ~2 weeks, engine will overheat. Have replaced the pcv part twice to no avail. Initially, mechanic recommended replacement of piston rings. Audi must recognize problem as they are no longer selling rings; owner must have complete pistons replaced. This is an expensive fix. This complaint appears common across Audi Q5 owners of this model year. Previous model years were recalled for same issues; clearly the issue was not addressed in later model year either.
Pcv valve needed to be replaced because it was causing extremely high pressure within my oil tank.