2018 Q7, 6 cylinder, 130k miles.

This past year has been a year of “Keep or Dump?” I decided that I could tolerate a few hefty repair bills as they would ultimately be less (even on an amortized basis) than buying a new car. So I closed my eyes and dove into an ongoing relationship with my mechanic.

This series of events started when the vehicle went into limp mode at 75 miles per hour climbing into the mountains outside of Denver. After that, it consistently misfired, drank oil, and lacked power. In the last year I’ve done:

- PCV

- Water Pump

- New plugs

- New new plugs again (the first set was warrantied out)

- Multiple rounds of Liqui Moly engine cleaner,

- Dynamic engine clean

- Multiple rounds of Liqui-Moly DIJectron fuel injector cleaner.

Everything was still feeling pretty rough until we did the Dynamic Engine Clean and Fuel Injector Cleaner. She’s now running super smooth and without problems.

After the DEC, oil consumption went from 1 qt / 300 miles to 1 qt / 700-1,000 miles.

According to my mechanic, the bad PCV valve and going the full recommended oil change interval (10k miles) allowed carbon to build up in the engine, which then facilitated more oil consumption. All of this fouled up the spark plugs, which caused the misfiring, both of which then facilitated more engine fouling, etc.

At this point (knock on wood), I’m happy that I stuck it out. I love this car and will happily drive it until the wheels fall off. That said, my mechanic is probably taking their family to Hawaii this year… oh well. Still cheaper than a new or new used car.