Hyundai Santa Fe Diesel Problems

There’s no point giving an engine a double-dose of whatever the manufacturer recommends as the correct amount. And that applies to everything from injector cleaner to windscreen washer fluid. It’s also true that these injector cleaners will sometimes work if the problem is a simple case of a build-up of dirt and gunk that shouldn’t be on the injector, but if the problem is an actual worn injector or some other problem, then all the cleaner in the world won’t help. You’ve asked if the condition might improve with time, and in the case of a dirty injector that is gradually cleaned by these products, then the answer is maybe.

The fact that your engine runs perfectly once warmed up is the interesting part. That suggests that there’s something going on when the engine is first started. Does it start easily? If not, the glow-plugs (which pre-heat the combustion chamber on a diesel) could be malfunctioning. I’d also be checking the fuel delivery pressure as these modern, common-rail diesel engines use very high fuel pressure to work properly. If the injectors aren’t getting the correct pressure from the moment you hit the key, they can run very poorly. That would then lead me to check for a dirty fuel filter and perhaps even the condition of the pump and its regulator. You might even find the problem is related to the turbocharger or even the throttle-by-wire system that is having a temperature-related hissy-fit.

The first thing to do now would be to have the vehicle scanned and, in particular, look out for fault code P0401. This will be logged as a problem with the EGR system, but is often caused by carbon build-up in the engine rather than a problem with the actual EGR valve. This fault code can also be associated with loose turbocharger plumbing which can lead to boost leaks and the sort of sluggish behaviour you’ve noted. Either way, it’s a good clue about where to look. It’s also worth noting that Hyundai was aware of a problem with the engine fuel-filter fitted to engines built around the time of your car. A change of the filter cartridge was a simple fix, so make sure that’s been done on your car. A Hyundai dealership will be able to check if your car was affected and whether it’s been fitted with the new filter.

You can work this out mathematically if bald numbers don’t scare you. The petrol four-cylinder Santa Fe is $3000 cheaper than the diesel. In all-wheel-drive form, the diesel has an official combined fuel consumption figure of 7.5 litres per 100km, while the petrol scores 9.3 litres. That means, that for every 100km travelled (based on those official test figures, remember) the petrol will use 1.8 litres more fuel. Based on $1.50 per litre, that means the petrol will cost about $2.70 more to run for every 100km, and that means you’d need to cover roughly 111,000km before you broke even on the extra purchase-price of the diesel. Even then, it’s not that simple as the diesel might be more expensive to service and maintain. Either way, though, petrol starts to look good.

That said, you sound like you’re in the perfect situation to make the most of a diesel engine. Yes, the turbo-diesel will tow a small caravan better than the four-cylinder petrol Santa Fe and, provided you do at least some country driving every month or so, you shouldn’t need to worry about the diesel particulate filter filling up or failing. Country driving will also stretch the diesel’s fuel consumption advantage further.
My advice? Drive both and make a decision based on the smoothness of the petrol or the relaxed flexibility and towing smarts of the diesel.

The diesel is rated to tow up to 2.5-tonne so it should handle your camper with ease. There are a few reports of transmission/transfer case failures, as your mechanic has told you, but it’s not widespread, and with a warranty that lasts for five years with unlimited kilometres you should be well covered if something does go wrong.

You’re not doing many kilometres and only short trips, so would go for the petrol version.

It is rated to tow a maximum of 2000 kg if the trailer has brakes, but only 750 kg if it doesn't.

Your mechanic is living in the past, perhaps because he could be out of a job on servicing your car. The Hyundai has a five-year warranty with capped-price servicing, so you know the service costs before you start, and it's still inside the original warranty period so has factory backing.

The Santa Fe gets The Tick, and several friends are very happy with new ones. Kia has also just totally overhauled the Sorento and that's definitely worth a test drive.

You are well within the rated towing capacity with trailer brakes, so the vehicle should be able to handle the hills as long as you approach them sensibly by being in the appropriate gear before you start climbing and don't try and rush it. If you are unsure of the weight of the fully loaded trailer have it weighed at a weighbridge.

There is also a petrol-engined Santa Fe. The crossover point for getting the money back on diesel power is about 30,000km a year.

Finding the cause of an intermittent problem is difficult because it doesn't always occur when the mechanic is there to witness it. It means he's flying blind when attempting to diagnose it. Likewise, if it doesn't happen when the diagnostic equipment is connected everything will indicate normal. The only thing you can do is to persist with the dealer and urge him to continue to seek a solution. It might help if you to set up a video camera in the car and have it running every time you drive the car and record it when it happens. That would show the dealer that it does actually happen and you're not making it up, and might give him some information that might help trace the problem.