Ask The Guide

The best way to test the operation of a fuel-injected car’s sensors is to have the vehicle scanned at a workshop with the necessary computer gear. The error codes that are revealed will tell you exactly what’s going on and save you the time and money of replacing bits and pieces until you find the actual culprit.

As for your symptoms, black smoke from the exhaust usually indicates a too-rich air:fuel mixture which could be the result of worn injectors, incorrect fuel pressure or a faulty temperature sensor. There are other causes, but those are the ones I’d investigate first. After a scan, of course.

The six-speed automatic in your car has experienced a lot of serious problems, Linda. Various components have been blamed, but the symptoms include failure to select Reverse which sounds like the problem you’re having. Other symptoms include flaring between gears, loss of drive, inability to select forward gears and a warning light showing up on the dashboard.

You might be lucky and simply need a top up of transmission fluid, but going by the history of this gearbox, you need to have the car electronically scanned to know what’s really going on.

Oil leaks are a pretty common complaint in a second-hand car, but if the car as sold to you with a roadworthy certificate (which it almost certainly should have been) then there’s no excuse for those to reappear within two weeks of you taking ownership. I’m always suspicious of a second-hand car with a sparkling clean engine bay, as it usually means it’s been cleaned up to hide leaks, just as you’re now discovering.

Given that you bought the car from a VW dealership, I’d be having a chat with VW Australia’s customer service and complaints people as there might be something they can do to help in getting the situation sorted out to our satisfaction. On top of that, the dealer who sold you the car has an obligation under the terms of the second-hand car warranty. In WA, that means any second-hand car less than 12 years old (which a 2010 model is) and with fewer than 150,000km travelled, has to carry a one-month warranty on faults like the ones you’ve described. Since these problems were spotted at the two-week mark and pointed out to the dealership at that point, you should be covered.

The bigger issue from your point of view, of course, is that you were told the car had never been crashed when, in fact, it appears that’s not the case. That would seem like a fairly straightforward case of misrepresentation to me, and I’d be having the car professionally inspected (try your local State motoring club) and getting in writing the fact that it’s been crashed and repaired. From there, I reckon you’d have a decent chance of getting your money back and returning the car.

The standard differential on this vehicle was a non-LSD (non-limited-slip) unit with a final-drive ratio of 3.08:1. Some owners changed the gears in the diff for more acceleration, although this was more commonly done in V8 models where owners were chasing performance at the expense of a little fuel economy.

If you’re in doubt, you can put the car on a hoist, mark a spot on the driveshaft and then turn the rear wheel a full revolution. By counting the number of times the driveshaft rotates during that process, you’ll know the ratio. In this case, one full rotation of the rear wheel should equal 3.08 rotations of the driveshaft.

The symptoms you have certainly suggest an engine with far too much blow-by (combustion pressure escaping past the piston rings and into the crankcase). Sometimes, the same symptoms can be caused by a crankcase ventilation system that isn’t working properly, but it’s often blow-by that’s the cause. That’s usually the result of internal engine wear which, at 290,000km and counting, is hardly out of the question.

Basically, the observations you’ve made regarding crankcase fumes are about as far as you can go without actually performing a compression and cylinder leak-down test. The good news is that these tests aren’t overly complicated and don’t take long, but they will give you a vastly more accurate idea of what’s going on inside the engine. Oil in the intercooler can also be a sign of this sort of wear, but, as you’ve been told, can also be the fault of blown turbocharger seals. Either way, it sounds like your engine is due for a freshen up in the name of reliability and clean running.

There’s good and bad news here, John. The transmission in the car you’re looking at is code-named DL501 and it’s a wet-clutch design. That’s distinct from some of the dry-clutch designs also used by the VW Group which were much more troublesome with a high rate of failures. That’s the good news.

The bad news is that even with its more durable wet-clutch design, the DL501 has also been known to suffer what appear to be inherent problems. Mainly, those relate to the mechatronic unit (more or less the transmission’s central nervous system) and premature wear in the clutch plates themselves.

The car you’re looking at has covered a very low distance, so it should be okay for now, but there’s no telling what dramas might crop up with years and kilometres. The problems will likely be worse if the car has not been serviced by the book, so check the service handbook for evidence of this. Even then, it’s a bit of a gamble.

But the only thing I’d stay further clear of than a DSG transmission would be an extended warranty from a car-yard. These are specifically written to exclude the things you’re most likely to need them for. Have a close look at the fine print and you might find that the sort of transmission problems you’d expect in this car will be specifically excluded.

I’d go for a fully synthetic engine oil with a viscosity rating of 5W-40. The turbocharged 1.8-litre engine in that model is a pretty hard-working unit and quite a complex engine, so frequent oil changes are critical to its longevity. The brand of oil is not so important, provided you use a quality brand and not the Brand-X stuff sold at supermarkets and some online clearing houses. Don’t forget to change the oil filter at the same time; putting clean, fresh oil through an old, dirty filter makes no sense at all.

Hyundai’s diesel engines are generally regarded as being among the better ones on the market. That’s probably because the South Korean domestic market has been switched on to small capacity diesels for decades and, as a result, Hyundai has been building them just as long.

But, like any modern turbo-diesel, the iLoad’s diesel can be prone to a build-up of black gunk in the intake system, a result of diesel soot and oil mist mixing as part of the vehicle’s own emissions-control systems. The other problem that has cropped up a few times now is a failed turbocharger unit. Generally, this has been the result of a blocked oilway that feeds lubricating oil to the turbo’s bearing. This is a narrow oilway and any sludge in the engine can block it and starve the turbo of its oil. Which is when the turbo itself fails.

That’s far more likely to happen in a vehicle that has not had the correct maintenance with regards oil changes. So check the service handbook before handing over the cash and only buy a second-hand iLoad with a full and correct service history.

It all depends on whether you bought the car privately or from a licensed used-car dealer. If it’s the latter, you might have some redress under the mandatory warranty conditions in your State. If you bought the car privately, I’m afraid there’s no comeback at all beyond contacting the seller, explaining the situation and perhaps coming to an arrangement on a refund or part-refund. I wouldn’t be holding my breath, however, and a private seller usually has no obligations whatsoever to make your problem their problem. Did you have the car independently inspected before the purchase? If you did, I’d be taking the matter up with whoever did the inspection, because a faulty transfer case should perhaps have been picked up as part of any pre-purchase test.

If the transfer case is damaged beyond repair, you’ll need a new one. The problem there is that the only Mazda 6 that featured this driveline (with a transfer case) was the MPS model which only sold in small numbers. So you might have trouble finding a second-hand one. Even the main gearbox (a six-speed) was different to the manual gearbox (a five-speed) on the other Mazda 6 models.

If the new clutch helped the vehicle climb hills, then I dare say that was money well spent. As for noises from the engine under load, I’m afraid that’s a job for somebody on the spot who can listen to the vehicle and make an assessment. The noise could be major internal problems or it could be something as simple as a loose heat shield under the car. Even a loose or worn engine mount can create all sorts of mysterious and expensive-sounding noises and rattles.

Don’t forget, your vehicle came with a five-year factory warranty, so a major failure that is not the result of mis-use or general wear and tear (provided the vehicle has travelled less than 130,000km) is still covered by Isuzu.