Hyundai Tucson Problems

It could be either the car or the remote-control unit at fault, and it’s impossible to tell without actually examining the vehicle. A remote-control unit with a battery that is low on voltage can cause all sorts of mysterious problems with a car’s central locking. But it’s also possible that the vehicle’s body-computer (which controls all the functions involved in unlocking and starting the car) could be malfunctioning also. If that’s the case, it will be a much more involved and expensive job than changing the battery in a remote-control unit.

The Hyundai brand has developed an enviable reputation in this country for reliability and quality. The brand’s warranty is also excellent, taking away even more buyer anxiety. With that in mind, the decision to go diesel or petrol comes down to the way you use the vehicle.

This applies to all brands, not just Hyundai, but if all (or most of) your driving will be urban or suburban based, then the petrol engine is for you. Yes, you’ll use a little more fuel than the diesel variant, but servicing costs could be a little lower and you’ll avoid the modern turbo-diesel’s biggest downfall; a blocked Diesel Particulate Filter (DPF).

The DPF is an emissions device that traps the soot from the diesel engine and burns it off at a later date. The problem with that is that the DPF can only burn off the soot and regenerate itself if the engine (and exhaust system) gets to a temperature high enough for this to happen. In urban running, that doesn’t just doesn’t happen, at which point the on-board computer will either try to force a regeneration (not always successful) or the DPF will have to be manually cleaned or even replaced (and that’s costly).

The bottom line, then, is that a turbo-diesel (even a modern one) is only for you if you will be driving the car at highway speeds for at least half an hour at least once a month (once a fortnight is better). If that’s how you use a car, then the diesel should be okay; if not, it’s petrol every time.

That’s a pretty comprehensive rebuild of the fuel system, so it’s possible that something that was removed at the time has gone back on not quite the way it was. A shuddering as you slow down suggests that the idle speed is perhaps a touch low. You should be able to adjust the ide speed fairly simply, so the first thing to try is to creep it up, say, 100rpm and see if the shudder goes away.

A mechanic will be able to do this quickly and easily. If that’s not the problem, you need to go back and double check every fitting and fastener to make sure there’s no air or fuel leak that is causing the engine to develop the staggers. Were the new injector seals treated to a dollop of rubber grease before they were installed? If not, there’s a chance that fitting them may have put a small tear in the rubber seal which is now leaking.

Whenever you see a bunch of problems all occurring at once, the car’s body computer becomes a prime suspect. This computer is what controls functions such as door locking, power mirrors and windows, the anti-theft measures, cruise-control, lighting, wipers, powered seats, the dashboard and much, much more. All these functions can go haywire or stop working altogether (and all at once) when the body computer says it’s had enough.

Since your car has electrically controlled steering, the body computer will have a say in that as well, which could explain the weird noises. But either way, you shouldn’t drive the vehicle any farther. Any noises or strange symptoms in a car’s steering could mean a sudden loss of control at the worst possible moment.

It sounds very much like there’s a blow-by problem with this engine. The pressure created by the combustion process is somehow getting past the pistons and into the crankcase, causing the dipstick to leave its tube and blowing oil all around the engine bay.

Blow-by is often caused by worn or broken piston rings or a damaged piston itself. But modern turbo-diesels are also prone to problems with their crankcase ventilation and emissions-control systems which can become full of gunk and not allow the crankcase to breathe properly. At which point, the same symptoms can occur.

A mechanic will be able to do some tests and determine what’s causing the pressure build-up inside the crankcase. If it’s internal wear, a rebuild may be required. But if it’s a build-up of crud inside the emissions-control systems, a manual disassembly and clean might be required. Either way, your car’s warranty might cover you for this, so the Hyundai dealer is your first port of call.

The engine in a modern car has inbuilt protection where it won't rev beyond what is safe for it. So you needn't worry about that. But a vehicle that wants to hold gears too long can become tiring to drive, as well as using more fuel than it might if its shifted gears at lower engine speeds.

Your car has what are called drive modes which tailor the aggressiveness of the throttle and alter gearshift points to tailor the car's behaviour in different conditions. My suspicion is that your car is set on Sport which is what's making it feel a bit hyperactive. There's a switch on the centre console which will allow you to change the Drive mode to Comfort or Normal. Try that to see if it tames the gearbox's behaviour.

The engine in a modern car has inbuilt protection where it won't rev beyond what is safe for it. So you needn't worry about that. But a vehicle that wants to hold gears too long can become tiring to drive, as well as using more fuel than it might if its shifted gears at lower engine speeds.

Your car has what are called drive modes which tailor the aggressiveness of the throttle and alter gearshift points to tailor the car's behaviour in different conditions. My suspicion is that your car is set on Sport which is what's making it feel a bit hyperactive. There's a switch on the centre console which will allow you to change the Drive mode to Comfort or Normal. Try that to see if it tames the gearbox's behaviour.

The extra purchase price of a diesel engine over a petrol one is only the start of the cost comparison. Generally speaking, diesels will cost a bit more to service (it depends on the make and model) and that’s if you don’t have problems with the diesel particulate filter (DPF) or soot build-up in the engine’s intake system that needs to be manually cleaned out.

You also need to consider your driving habits to decide whether a diesel is right for you. As a rule of thumb, if you don’t go for a decent drive at highway speeds for about an hour or so at least once or twice a month, then a diesel is not for you. Using a diesel engine exclusively for short trips at suburban speed can often see the DPF requiring more attention than it should, and that equals cost.

Also, modern petrol engines have really closed the fuel-economy gap that the diesel once enjoyed. The fuel consumption difference between the diesel Tucson and the petrol version is likely to be about a litre per 100km (based on the official combined figure for each). That means that even at $2 per litre (and based on the $6000 difference in price you’ve quoted) you’d need to drive 300,000km before the diesel began to pay for itself in terms of fuel saved. I’m not sure there’s a full $6000 separating the two versions of the Tucson, but even so, you get the idea.

If a car overheats (for whatever reason, but a blown head gasket is a prime cause of this) the damage to the engine internally can be catastrophic. Pretty much any component can be compromised after an overheating event, so knowing where to start looking is the big question here.

Changing the head gasket requires removal of the cylinder head, and reassembly involves making sure that the camshaft timing is reinstated correctly. If there’s been a mistake made in this regard, the engine will almost certainly not run. 

Certainly, injector failure is not unknown in modern turbo-diesels, but the fuelling system on a modern, common-rail turbo-diesel is a complex, fine-tolerance arrangement, so you also need to check the filters, fuel pump(s) and operating pressures. Even then, you might find that a simple, cheap-to-replace sensor is the single component preventing the vehicle from running.

I’d start with an electronic interrogation of the car’s computer. The problem there is that if the car hasn’t actually run with the issue that’s preventing it from starting, the computer may not have had the opportunity to log the problem in the first place. That said, a simple fault code might be all you need to know to move forward, so a scan is in order. Beyond that, it’s back to first principles, checking the timing and clearances of all the mechanical bits and pieces, including having the injectors bench-tested.