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Hi Janie,

On the parking sensor issue, it just seems to be a bit of a quirk with the Audi Q7 that to get the front sensors on when moving forwards, you have to press the parking sensor switch, although they do, as you point out, come on automatically when you select reverse. We’re not sure why this is, but it might be worth a visit to your dealer to see if there’s some finicky bit of software code that can be re-set to activate them automatically at low speeds.

As for the stop-start system, if could be a few things. Obviously, there may be a fault, in which case get the car booked into your dealer for a check-up. Or it could be that you’re doing a lot of low-mileage, short runs, which aren’t allowing the engine and other systems to get fully up to temperature. Stop-start isn’t a simple on/off system — it’s controlled by the engine management and that won’t let stop-start activate if it thinks that the engine hasn’t warmed up enough (stopping and starting a cold engine can be damaging) or if it has detected that you have a lot of high-energy drain systems (air conditioning, demisters etc) running. Try and analyse your driving the next time you go out and see if any of this fits. If not, head for your dealer. 

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Hi Aisling,

Our information would agree with what you were told, that the recommended interval is indeed 210,000km, regardless of time. Remember: treat that as a maximum, not a minimum...

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Hi Hugh,

Prices for changing the belt will vary depending on the garage you bring the car to and whether they use genuine Audi parts, so best thing to do is shop around. I can tell you that, assuming you have a 2.0-litre TDI diesel model, the work should take no longer than three hours.

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Hi Colin,

There are well-documented issues with stretching VAG timing chains, unfortunately, and yes, it's very expensive to replace a chain. The problem is usually identified by a distinctive rattling on cold start-up before it manifests itself in engine running issues and there are also chain inspection ports on these engines so, if a car you're looking at has had proper maintenance, you can have the chain inspected.

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Hi Anthony,

You should be fine, actually. Your 3 Series should (emphasis on SHOULD) be worth around €22-25,000 as a trade-in, and a 171 4 Series Gran Coupe starts at around €30,000-ish, so adding €10k of change-up budget should put you in the right ballpark. Ditto the A5 Sportback, although you will find examples of both on a 171 starting with a €4 rather than a €3… Shopping around a bit should do the trick, though. Both cars are excellent choices, and go for the Audi if you want maximum reliability.  

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Hi Tracy,

I'm afraid without knowing exactly which car you have, this is impossible to diagnose. You should bring the car to a good mechanic or auto-electrician.

There are many reasons for a stop-start system to not always work. Read this question and answer on that subject for instance.

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Hi Stephen,

The timing belt needs to be replaced every 210,000 kilometres, regardless of time. The cabin filter needs replacing every 60,000km/24 months, but there is no set service interval for the air conditioning system itself.

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Hi Stuart,

Not for some time yet. The recommended minimum change period is every 210,000 kilometres, regardless of time.

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Hi Anna,

There are plenty of reasons why a stop-start system won't work in certain circumstances. It's different for every car, but it's well worth reading this other reader question for a general overview, even if it doesn't specifically apply to your car. 

If none of that helps, then pop along to your Peugeot dealer, as the car is still under warranty.

Expert answer

Hi Donna,

For the first-generation Audi Q3 (pre- and post-2015 facelift), regardless of whether you have one of the 1.4-litre TFSI petrol engines or any of the 2.0-litre TDI diesels, the recommended maximum interval (regardless of time) is 210,000 kilometres. The 2.0-litre TFSI petrol model uses a timing chain, not a belt.