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Hi Paul,

The biggest issue is the infamous N47 diesel timing chain problem. The engine was designed with a zero-maintenance timing chain, mounted at the back of the engine, which then proved prone to (costly) failures. Most will have been fixed or replaced by now, but it’s still something to be cautious of. The rest is mostly irritating electrical issues, but just make sure you don’t buy one without a very full service history.

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Hi Leanne,

The set interval is every 160,000km or 10 years, but we would recommend getting the belt changed sooner than that — say at around 80,000km, just for safety’s sake. It’s a small extra expense to save a potentially catastrophic engine failure. Also, on that engine, beware of the oil pump leaking on the cam-belt and causing it to slip.

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Hi Cathal,

The Qashqai would be a reliable car in general terms, although they do tend to suffer from sagging suspension and occasional turbocharger failure on the diesel model. The engine management system can also go awry. The Corolla is perhaps not as perfectly reliable as is sometimes painted, but overall I’d expect it to be a little more reliable than the Nissan. 

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Hi Brian,

There have been intermittently reported issues with Toyota gearboxes across the board, from sticking shifts to complete failures, but they tend to be quite rare overall, so if the car you’re looking at has a full service history then it should be OK. Ask for a warranty if you're really worried about it.

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Hi Liam,

This is a bit of a grey area. The NCT manual that the testers are supposed to adhere to makes no mention anywhere of a rear wiper, but generally we find that, if a car has something and it's broken, the testers will often flag it up as a possible failure. We wouldn't take the risk, especially as wipers are so cheap to replace.

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Hi Raj,

Generally, I wouldn't think that a gearbox issue would damage an engine - it's usually the other way around, and if there were a gearbox issue, the engine management system should pick up on it and adjust things accordingly.

But... Audi gearboxes are usually pretty robust so the fact that this one has failed could be an indication that the car has been abused or not cared for properly. Fair enough, it could be a genuine 'just one of those things' failures, but it might be worth getting the car inspected by an independent engineer such as the AA to allay any fears. 

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Hi Alan,

All are, in general, pretty solidly reliable cars as you would expect,  but the issues come with the added weight and complexity of those folding hard-tops. All three can suffer roof failure (often at the point of being half way up or down) and all three suffer equally from increased tyre and suspension wear relative to their hatchback cousins, not to mention higher fuel consumption. None, to be honest, are especially pleasant to drive.

Of the three, I’d say the Eos is the best built, the Focus by a slim margin the best to drive and the Astra fractionally the roomier in the back seat. As an alternative, what about an Audi A4 Cabriolet? You’d have to go for an older one to match the price, but it’s a better car and a better convertible than any of these. Alternatively, if you don’t need the back seats, get a Mazda MX-5 – literally the only small convertible that’s actually worth buying.

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Hi Noel,

Not bad actually – comfy and hugely economical, but check it carefully for electrical faults and clonking suspension, not to mention any possibility of diesel particulate filter failure. And don’t dare buy it if it doesn’t have a full service history.

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Hi Wendy,

Um, I'm afraid you're into a bit of bother here. Since 2013 if a car is going to be taken off the road, you have to declare it in advance with a form available at all Garda stations. Failure to do so is quite a serious offence, and 'forgetting' won't be accepted as an excuse. 

I hope you've got a good solicitor...

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Hi Amrinder,

There was a recall for 2.2-litre Mazda6 diesels to replace a stretching timing chain, so check to see if that work has been carried out and don't buy a car that hasn't had the work done. Any car with a full (and preferably Mazda main dealer) service history should be fine though.

However, the DPF issue is down to your driving - if you're not putting in the miles, the DPF can't get hot enough to clean itself out and that's when you get problems, so don't go for one of these cars (or any diesel, really) if you're only doing low mileage and short hops.