Used Audi Q7 review and buying guide (2006 to present): which one to buy and what to check

Which used Audi Q7 should you buy?

Buy the Q7 of either era that passes two checks: it sits level after a night parked and, if it's a 3.0 V6 TDI, it starts from cold without a rattle from the back. The timing chain tensioner fault covers every 3.0 V6 TDI Q7 built up to 2018, so it reaches past the 4L into the newer car too, and neither era is the clear safer pick on the evidence.

The car that arrived in 2015 has no air suspension fault row against it, but that's a gap in the record rather than a clean bill. Owners have reported a front radar sensor fault at 48,000 miles and a snapped rear coil spring at 47,000 miles on 2015 cars, a whine pulling away and stopping on a 2017 car at 6,300 miles, and a B pillar rattle on a 2016 one. Each is one owner's car, not a pattern, but ask the seller about all of them.

On a 4L (2006 to 2015), the one to buy sits level after a night parked, shows no suspension warning and comes with bills for any air suspension work. The High known fault applies to cars with adaptive air suspension and shows up between 70,000 and 120,000 miles, so go into a car in that band knowing the compressor and struts are the parts at stake.

Which Q7 engines and gearboxes are the safe choices?

The 3.0 V6 TDI is the engine to be careful with: its timing chain tensioner is a High known fault on Q7s built up to 2018, showing between 80,000 and 140,000 miles, and the chains sit at the back, so the engine has to come out to fix them. The rattle commonly starts around 90,000 to 100,000 miles, and long-life oil with stretched service gaps is blamed for wearing the tensioner early.

So if it's a 3.0 TDI you're after, favour one with frequent oil changes on paper over one run on long-life intervals, and treat a car past 80,000 miles with no record of chain work as the risky one. There isn't a proven safe diesel to point you at instead: the only other engine owners mention is the 4.2 TDI, where one owner had limp mode with the glow plug and engine lights stuck on.

If the paperwork shows the car has ZF's eight-speed automatic, don't accept the filled-for-life line. Audi treats its oil that way, but ZF offers official oil-change kits for the unit, and the interval on record is 60,000 miles or 96 months. A car well past either figure with no gearbox oil change in its history is one to question hard before you hand over a deposit.

What should you check when viewing a used Q7?

Ask to see the car after it's been parked overnight. A Q7 that's sitting low or leaning, an amber or yellow suspension warning on the dash, or a compressor that keeps running and sounds noisy all point to the known air suspension fault. One owner of a four-month-old car had an air suspension software problem the dealer couldn't cure, so a warning light on a young car still counts.

On a 3.0 TDI, get the engine started from cold with the bonnet up. Metallic slapping or rattling from the back of the engine that carries on past 3 seconds, or an engine management light, is the tensioner, and from 80,000 miles that's the sound to listen hardest for. Ask for invoices for any chain work and for the oil changes, with the dates and mileages on them.

Smoke from under the bonnet is worth ruling out too. One owner of a 2011 car at 120,000 miles had a fuel injector lift out when its bolt snapped, and paid £1,000 to have it put right, then £830 to have all the bolts replaced after a second injector did the same. Ask the seller straight out whether any injector work has been done, and ask to see the bill if it has.

Try every button, screen and lock. One owner of a 2007 car needed new MMI buttons and then a new dash display after smoke and a burning smell came from the dashboard, and another had all four door lock motors fail together on a four-year-old car. Lock and unlock each door from the key and from inside before you agree a price.

Paste the advert into the free check and it runs these against the listing, the MOT history and the DVLA record before you travel.

Is a used Audi Q7 4L (2006 to 2015) worth the gamble?

Buy a 4L only if it holds its ride height after a night parked and, on a 3.0 V6 TDI, starts from cold without a rattle. The air suspension fault is a High known fault for exactly these years on cars with adaptive air suspension, and the tensioner fault covers every 3.0 V6 TDI Q7 built up to 2018. If either check fails, move on, because this is one to buy on condition and paperwork rather than the badge.

The air suspension fault shows up between 70,000 and 120,000 miles, when the compressor gives up or the struts start leaking and the car drops onto its bump stops. The tensioner fault on the 3.0 V6 TDI shows between 80,000 and 140,000 miles, and it's a big job because the engine comes out. A car inside both mileage bands is carrying both risks at once, so it needs the strongest paperwork of all.

Owner reports add to the list. One 2007 4.2 TDI went into limp mode with its warning lights stuck on after two visits to the dealer, one high-mileage car's front differential failed at 150,000 miles, and a 2011 car at 120,000 miles lost two injectors to snapped bolts. None of those is a known fault, but each is a reason to ask for the full history before you commit.

What does a used Audi Q7 cost to run?