My TDI Q7 journey starts here!

I bought a 2012 Q7 TDI for a family hauler and to tow my other cars.

This thing has all the torque and got 24 mpg on the first tank with me driving aggressively.

Plus it holds all of the equipment for my entertainment business too. This weekend I had just the third row seats folded down to fit fives boxes in the back. As the other weekend I had the second and third row seats folded down to fit eleven boxes in the back.

It has the CATA engine code version of the turbo diesel 3.0 V6. Pretty covered up until you remove the big engine cover to expose all of the wiring and hoses on top of the engine.


Since I got this Q7 without much service history I wanted to immediately do some service work on it. Plus the service due light was on too.

Also didn’t help that it had 17 intermittent fault codes stored in the ECU and a lot of fault codes stored in other modules.


After saving the fault codes and clearing everything I drove the Q7 home to find that nothing came back right away so that was good. Started with replacing all the filters (engine oil, air, fuel, and cabin/pollen filters) and changing the engine oil. The oil level was low and it was black so that was definitely worth doing.

Close up of the engine oil filter and fuel filter. Audi recommends an annual oil change after 10K miles but I think that is way too long unless you do nothing but light cruising on the highway every day. Then the fuel filter is the later style inline filter that is recommended to be replaced every two years or 20K miles but again that is in ideal conditions with good quality diesel fuel so after replacing this filter I noticed a good bit more power.

Surprisingly the engine air filter wasn’t too bad other than a few dark spots.

The cabin air filter on the other hand had quite a bit of nuts, dirt, and debris in the fins and the box so I am glad to be breathing cleaner air now.

All this stuff is pretty easy to reach with the big cover off as well. The oil filter is in the middle top of the engine. The fuel filter is on the left/driver’s side of the engine compartment with only two hoses and some rubber sleeves holding it in place. The engine air filter is behind the lid that comes off with just two push tabs once the inlet hose is removed. Finally (not pictured) the cabin air filter is under the right/passenger’s side of the dash with a quick cover that comes out and two 5.5 mm trim screws hold the cover on under it.



After doing that beginning maintenance I thought this Q7 was painfully slow and didn’t get the fuel economy that I wanted so I checked the performance with my dragy to find that it ran a 17.21-17.32 seconds ET @ 81.37-81.75 mph in a 1/4 mile with a 9.93-10.11 seconds 0-60 mph time.




The stock 2012 Q7 TDI is rated at a 16.4 seconds ET @ 83 mph according to Car and Driver. Needless to say I needed to fix this thing.