Toyota RAV4 Problems

A noise or vibration that is engine speed dependent is usually associated with the driveline, while a similar problem that occurs at a particular road speed is more often a problem with a wheel or suspension component. The main exception to that is the differential which is part of the driveline but determines the vehicle’s speed, so can contribute a speed-dependent noise or vibration, too.

Beyond that, you could be looking at a fault with a wheel bearing, a deformed tyre, bent rim, worn suspension bush, bent axle or suspension arm or pretty much anything else. A rolling-road dynamometer (kind of like a treadmill for cars) might be one way of achieving the problem speed while a mechanic looks and listens on.

It all depends on what you call the serpentine belt. If you mean the toothed rubber belt that drives the camshafts, then yes, the engine will need to have its valve timing re-set before it will run again with a new belt. If this is what has happened, you’re lucky that the 3S-FE engine in your car is what’s called a non-interference engine. That is, if the belt brakes, the pistons will not crash into the valves, destroying the engine. In an interference design, you’d be looking at a whole new engine.

If, however, the belt you refer to is the one that drives the power-steering pump, water pump and alternator, then you should be able to simply replace the belt and be back in business.

That’s getting up there for any car, even though modern engines are capable of much greater distances than their older relatives. But that sort of mileage does raise some questions.

Those start with how complete is the service history. If there are any gaps, this would be a car to avoid, as any vehicle with that sort of distance covered will only be as good as its servicing and maintenance allow. The other question is what sort of life the car has led. Three hundred thousand kilometres sounds like a lot, but if you break it down to kilometres per year, it works out at less than 18,000km per annum, which is well within the bounds of normality.

However, the bottom line is this with all high-mileage vehicles: You might get lucky and get another 150,000 trouble-free kilometres out of the thing, or it might go bang tomorrow. That’s the punt you take and that’s why high-milers are cheap to buy. Which is another way of saying that even with a full service record, a RAV4 with that sort of mileage would still need to be cheap.

The first piece of advice here is to not drive the car at all until this problem is fixed. A car with faulty brakes is one of the most dangerous situations you can find yourself in, and it’s just not safe to even attempt to move it, even to relocate it on the driveway. The problem could get a lot worse very quickly, leaving you with no brakes at all. And even if it doesn’t get any worse, your limited braking capacity could make an emergency situation much, much worse.

The noise is probably not brake-line pressure escaping, since you don’t have falling brake fluid levels. At which point, my suspicion becomes that the brake master cylinder is at fault. This is a device that uses vacuum from the engine to assist you to push the brake pedal. If the diaphragm inside the booster fails, you will might hear the vacuum escaping, with a hissing noise. Even if the booster is intact internally, a simple hose that connects the booster to the engine could have split and caused the leak. Until it’s fixed, though, you won’t have full braking power and that’s, obviously, very dangerous.

The kerb weight of the RAV4 you mentioned depends on whether it’s the two or four-wheel-drive model. If it’s the former, the kerb weight is 1690kg, if it’s the all-wheel-drive model, the kerb weight is 1775kg. I know you asked for tare weight, but the only difference between kerb and tare weight sis that tare weight is the mass of the empty vehicle with 10 litres of fuel in its tank, while kerb weight is the same empty vehicle but with a full tank of fuel.

Of perhaps more interest to anybody towing is the fact that the two-wheel-drive RAV4 can tow 480kg while the AWD version can cope with 1500kg. The 2WD Rav’s GVM, meanwhile, is 2185kg and the AWD’s is 2230kg. The two-wheel-drive RAV4’s GCM is 2665kg, while the all-wheel-drive’s GCM is 3730kg.

Some of this information is quite difficult to find (even if you have the owner’s manual) yet it’s crucial safety information and should be more readily available. Some car makers seem very coy about publishing GVM and GCM limits, possibly because they don’t always reflect well on the product’s ability to tow and carry a load at the same time.

The most common cause of this problem is a flat battery. Often, a battery will have just enough charge remaining to switch on the dashboard lights (which don’t need much power to operate) yet be too flat to actually crank the engine (which requires a huge amount of power).

You can have the battery charged and its overall condition checked, as well as the vehicle’s charging system. You may also find you have something as simple as a loose battery terminal that is not allowing the charge to flow a freely as it needs to.

It all sounds a bit counter-intuitive, doesn’t it: That a smaller engine could use more fuel thana larger one? But, in fact, it’s all down to the hybrid driveline in the 2.5-litre version of the RAV4. Because the hybrid version also has an electric motor to help propel the vehicle, the petrol engine has less work to do. So, it uses less fuel, particularly on the official test cycle that determines these numbers.

In fact, in the hybrid RAV4, the petrol engine isn’t even running a lot of the time, especially in stop-start traffic. The electric motor can draw from the batteries on board to get the vehicle rolling, and when it’s slowing down, the electric motor recharges those batteries for the next green light. And when the car is running on electric power, it’s not using any petrol at all.

By contrast, the non-hybrid RAV4 is running its petrol engine the whole time (apart from when it’s at a complete standstill). And that, in a nutshell, is how a bigger engine can use less fuel than a smaller one in the same make and model.

There’s a huge range of towing limits for the RAV4 thanks to the sheer number of model variants. In simple terms, the non-hybrid two-wheel-drive versions can tow a braked trailer of 800kg while a two-wheel-drive hybrid RAV4 can only cope with 480kg. Which means that if you want a RAV4 for towing, you’re best to look at any of the all-wheel-drive versions (hybrid or non-hybrid) which have a braked towing limit of 1500kg.

Of course, those figures are for braked trailers, while your question was for a trailer with no braking of its own. In that case, the two-wheel-drive RAV4’s limit stays at 480kg, while the all-wheel-drive’s limit falls to 750kg.

Gross Combined Mass (the total weight of the vehicle, the trailer and anything being carried including passengers, fuel, luggage and accessories) meantime, is harder to find and you need to resort to the owner’s manual (which is a problem if you haven’t bought the car yet). In any case, the two-wheel-drive RAV4’s GCM is 2665kg, while the all-wheel-drive’s GCM is 3730kg.

I’m unsure why this last piece of the puzzle is so difficult to find, but information like this should be more readily available as it’s a critical safety issue and something that many owners inadvertently get wrong with serious legal and insurance ramifications.

Without a doubt, the best thing to do now is the have the car electronically scanned. That’s because there are literally hundreds of things that could cause this sort of problem, ranging from (but hardly limited to) a sick fuel pump, a blocked fuel filter, worn injectors, a fuel leak, poor ignition, a low-voltage battery, dirty air-filter, blocked or damaged exhaust, a stray electrical problem and much, much more. Even something simple like a fuel rail that is not holding pressure when the engine is switched off, can lead to symptoms very much like yours.

Hopefully, the on-board computer has logged these random starting problems and will be able to tell a mechanic what’s wrong. Otherwise you’ll simply continue replacing parts that weren’t the problem in the first place. And that costs time and lots of money.