Hyundai IX35 Problems

This was a huge problem for manufacturers back when turbo-diesels first started using Diesel Particulate Filters (DPF). The problems started when owners were using their diesel-powered vehicles just as they had their previous petrol cars. That is, for short, urban journeys where the exhaust system never got hot enough to perform a DPF regeneration (which is critical to the way these filters reduce tailpipe emissions).

To counter that, some manufacturers programmed the engine to dump extra fuel into the exhaust to get it hot enough for a DPF regeneration. Inevitably, however, sometimes some of that extra fuel found its way past the piston rings and into the engine's sump. And suddenly, there was more oil in the sump one day than had been there the previous day.

The problem there was that the diesel now in the sump was actually diluting the engine's lubricating oil, and that could lead to accelerated engine wear and bearing failure. The best solution – then and now – is to make sure you drive the vehicle at freeway speeds for at least an hour every three or four weeks. That will get things hot enough for the DPF to regenerate if it has to, and not rely on the extra diesel the computer will pour into the engine.

You could be looking at a specific DPF problem or maybe a software glitch that is messing up the regeneration, but if the level on the dipstick is rising, then I'd say that's your problem.

If you're selling or trading-in the car, then a quality, tested second-hand engine from a wrecked iX35 is probably your best bet. This will be the cheaper option and even though you could spend a lot of money having the current engine reconditioned or a brand-new engine fitted, you'll find that won't affect the resale value as much as the extra outlay.

That said, it all depends on what's wrong with the current engine. If it's completely trashed, then a replacement is the go. But if your engine has simply stopped working for a potentially simple reason, then it might be worthwhile fixing it and maybe saving even more money. Either way, making your car a proper running vehicle again will definitely justify the cost as it's virtually worthless in a non-running state.

As for other brands of engines, the only viable choice is the same engine that make and model came with from the factory. Trying to fit anything else is a whole new car of very expensive worms.

If a timing belt breaks, one of two things are likely. Either the broken belt will allow the valves and pistons of the engine to collide, instantly turning the engine to scrap. (This is what happens in what's known as an interference engine design.)

The other alternative is that the belt snaps, but no intrinsic metallic parts collide (this is the case in a non-interference engine). If that's the case, the car won't run, but if a new belt is fitted and the engine retimed, it should work perfectly afterwards.

But even in an interference engine, if the tensioner gets slack but doesn't actually allow the timing belt to jump ship or break, then there's a chance that you've avoided a catastrophic failure. The bottom line is that if your engine suffered a problem with the timing belt, but works properly after being fixed, then all should be good in the long run.

It sounds like you’re on the right track with the transmission, Melissa. Transmission oil goes black when it starts to pick up bits of burnt clutch and band material shed by the gearbox’s internal parts. If that’s happening, there’s also a good chance that the transmission is worn and that’s causing the lack of acceleration and slipping you’re experiencing.

This sort of problem can be caused by low transmission fluid levels, a worn out pump or just plain old wear and tear. A check of the torque converter’s health would also be a good idea, but on the surface, it sounds like the transmission is ready to be rebuilt. Have the vehicle scanned and see what faults – if any – are thrown up by the computer. It could be something simple, but the black transmission fluid tends to tell a different story. It should be a nice, clear red colour.

I don't think anybody these days considers less than seven years and just over 100,000km to be the lifespan of a modern engine. Certainly not in a car serviced properly. And since this is a known problem with these engines, I think you have a very good case for Hyundai to at least help out with the repairs on a pro-rata basis.

Our experience lately has been that some Hyundai dealerships have been ignoring cases like these and not giving them the consideration they perhaps should be. In any case, any decision to help out with repairs must come from head office, so I'd forget about the dealership for now and go straight to the top. Hyundai Australia has a customer service division and that's who you need to be talking to. Approaching the ACCC should be your last resort, but at least give Hyundai the chance to do the right thing by a loyal customer.

Premium diesel fuel seems to be one of those things that marketing departments, rather than engineering departments, have invented. It enables the fuel companies to charge you more for a product that is allegedly better, but nobody really knows why Premium diesel is an advantage.

At best, Premium diesel will have a few extra additives to help keep the engine clean inside, so maybe running a tank of Premium every now and then isn’t a bad idea. It won’t hurt. But don’t be fooled into thinking that your car will perform better in any meaningful way by switching exclusively to the more expensive Premium brew.

This is, of course, the opposite of Premium unleaded petrol which, depending on the car, can be a difference between happy motoring and expansive engine damage.

Hyundai’s Theta 2 family of engines does, indeed, have a pretty chequered track record for reliability. But it’s important to note that the majority of vehicles affected have been US-market cars with engines built in a different factory to the cars supplied to Hyundai Australia. For the record, the North American cars in question experienced debris from the engine machining process blocking the oil passages inside the engine, leading to bearing failure. In some cases, the engine failure resulted in a roadside fire.

Even though our iX35s were built in South Korea rather than North America, there’s still a chance the same problem could crop up here given that engineering materials and techniques tend to be standardised across all factories in the name of efficiency.

As you point out, your car is now out of warranty, but I wouldn’t leave it at that. I’d be talking to Hyundai’s customer service department with a view to at least getting some assistance in having the car fixed if, indeed, it was a manufacturing fault that caused the engine failure. I’d also be pointing out that 80,000km is not a realistic life expectancy for a modern engine. To get anywhere with this approach, you’ll need to be able to show that the car has been serviced by the book and (probably) that the failure was due to a loss of oil pressure that led to bearing failure.

The answer is no, but Hyundai's naming policy was very confusing during the 2010s.

The original i30 of 2007 introduced the alphanumerical naming policy and signified a different approach to vehicle engineering, with a European focus with higher-quality engineering rather than a low price to take on class leaders like on the Volkswagen Golf.

Thus 'i' something became a sort of premium nomenclature, and of course is still used to denote this on models like the i30 and Europe's i10 and i20 small cars There was also the German-engineered i40 midsized sedan and wagon until 2018.

But here's where Hyundai muddied its own waters.

In 2010 the larger, American-market Sonata was rebadged i45 for Australia and New Zealand – even though an 'x' and a '5' rather than a '0' meant crossover or SUV, as illustrated by the very popular second-generation Tucson being renamed ix35 in Australia and some other markets from 2009 to 2015 – though this naming policy was abandoned for the third-generation Tucson from 2015. While strikingly styled, there was nothing European about the i45, and it too returned to being badged Sonata from 2015.

So... i10, 120, i30, i40 and i45 for Australia, but no i35.

Thank you.

Finding critical safety information like this online can be fraught with danger. There are simply too many self-appointed geniuses out there who have little to no idea of what they’re talking about. Other times, you’ll be unwittingly reading about a vehicle specification from overseas that isn’t relevant to us, even though the badge is the same. And getting a bum steer on something like towing limits has awful potential consequences. Stick with websites like CarsGuide that you can trust.

On that basis, the Hyundai iX35 in question has a towing capacity of 750kg for an unbraked trailer and a 1600kg limit for a braked load. The tow-ball down-load limit is 140kg, the Gross Vehicle Mass is 2170kg and the Gross Combination Mass (the vehicle, trailer and all its occupants and luggage) is 3770kg. And just to cover all the bases, the factory roof-rack has a 100kg limit.

Checked against your choice of camper-trailer, you’ll find that the electrically-braked Road Trotter camper has a tare mass of 1090kg and can be loaded to a combined trailer-and-luggage weight of 1500kg. Its tow-ball download figure of 90kg is within the Hyundai’s capacity as well.

Anything can be made to work if you throw enough money at it, but the short answer, Bassel, is no. For the 2014 model year, Hyundai upgraded the petrol engines in the iX35, and the two-litre unit in your car received a direct-injection fuel system. While the basic engine architecture might be the same and the engine would probably physically bolt in, it’s almost certain that the computer in your car would be incapable of controlling the direct fuel-injection function. Your car is also probably missing components such as wiring, a high-pressure fuel pump and sensors required to make the newer engine operate.

You could also run afoul of the authorities because the earlier engine you want to use had a (slightly) higher tailpipe emissions rating. Our regulators take a fairly dim view of a vehicle being modified and going backwards on emissions.