Basic Audi 4.2 V8 TDI Engine Specs. The 4.2 VW/Audi TDI engine was developed in the early 2000s, with the official adoption year being 2005. This engine is still widely used to this day. This engine was based on the 4.0L V8 TDI and was included in Audi’s luxury limousines like the A8. engine won't turn over, won't start in the 2007 Q7. 2. keys automatically lock car in the 2015 Q7. 2. squealing from brakes in the 2017 Q7. 2. electronic stability program (ESP) malfunctioning in the 2007 Q7. 2. sunroof drains clogged in the 2008 Q7. Audi Q7 4,2 TDI. Audi claims that the Q7, with its new 4,2-litre TDI powerplant, is “the most powerful diesel SUV in South Africa.”. So, when I recently got the chance to get behind the wheel of this Q7, I was eager to see what it had to offer. Initially, all I noticed was the sheer enormousness of this vehicle. Save up to $6,125 on one of 4,220 used 2009 Audi Q7s near you. Find your perfect car with Edmunds expert reviews, car comparisons, and pricing tools. Worst Audi Q7 Problems #1: Squealing From Brakes 2017 Q7 Average Cost to Fix: $3,400 Average Mileage: 23,000 mi. Learn More #2: Catastrophic Engine Failure 2017 Q7 Average Cost to Fix: $18,000 516-766-2223. Buy 2007 Audi Q7 4.2L (ECM) Engine Control Module (PCM/ECU) with a FREE Lifetime Warranty. Get back on the road with our Plug & Drive Module. The V8 4.2 TDI diesel engines are exceptional worrying reliability. Some of them had problems with the consumption manifold and throttle. All bearing of axes, rods, and levers inside were made of plastic until 2009, which wear out really rapidly (40-50,000 miles). As a result, reduced power and torque because of various spaces and skews. Audi Q7 Vehicles With This Problem. 4 model years affected. 2007, 2008, 2009, 2011. Average mileage: 96,062. (45,000–177,500) Check Engine Light Diagnosis & Testing : $143 -$180. The average cost for a Audi Q7 Check Engine Light Diagnosis & Testing is between $143 -$180. Learn More. Search For a Specific Car Problem. Q7 Suspension problems. My 2008 Q7 has developed a fault with the suspension. I have tested the compressor today and it seems perfect - it run smoothly and is quiet. The rear stays very high regardless of what setting the system is set to and after a short drive I get the amber flashing light on the dash. The voltage should be between 13.5 and 14.8 volts with the engine running. Switch on the accessories in your Q7, for example, headlights, AC fan at full speed, and interior lights. The voltage should remain around 14 volts. If it drops and remain below 13.5 volts, it indicates a problem with the current supply from the alternator. 221GPR.