Ask the Guide

This is a typical car company response to the problem of pedal error which has raised its head many times since about the 1980s when car maker started getting sued by drivers who had pressed the wrong pedal, but claimed the car had accelerated of its own accord.

The solution was to make sure that if the driver accidentally pressed the throttle, if they also pressed the brake in panic, the car would stop accelerating. By pressing the brake and throttle together in your car, you’re reproducing that exact situation. So, really, there’s nothing wrong with your car, and it’s only doing what it’s programmed to do.

A lot of drivers don’t like this feature, however, as it means the slightest hint that both the brake and throttle are applied at once is enough for the car to cut its power and not move, as you’ve discovered. Many have found that when trying to enter fast moving traffic or make a quick lane change, and operating both brake and throttle at the same time for a quick getaway, this function is actually dangerous.

Unfortunately, there’s not a lot you can do about it other than learn to not even brush the brake pedal when you want to make a quick start.

Manual gearboxes generally work better/more smoothly when they have some heat in them and the oil gets a little thinner and better able to lubricate. So you’re right on that account. If the gearbox was crunching on every gearchange, you’d also probably suspect the clutch might be worn, too. But since it’s only the one gearchange that’s making the noise, then your theory that the synchromesh rings are worn holds water.

But before you do anything drastic, make absolutely sure the clutch is disengaging fully and that all the clutch lines and pedal action are spot on. A dodgy clutch can also produce this sort of crunching noise. And, yes, it can be worse when the vehicle is cold.

Meanwhile, for some reason, the synchromesh on second gear is the one most likely to fail on the majority of cars (probably because second gear cops and awful hiding and copes with very high loads). So, in that sense, yours is a copy-book case of worn synchros. (First gear is also highly loaded, but since you only really shift up from first – hardly ever down to first on the move – its synchromesh rings don’t cop such a spanking.)

If the problem gets worse, you’ll probably find the upshift from first to second will also start to graunch. That’s when you’ll know for sure that the synchros need replacing. As you point out, though, to really diagnose this the fault requires an inspection of the parts and that means the gearbox out and pulled apart. While you’re in there, change the other synchromesh rings and the transmission’s bearings. And don’t put it back together without a new clutch.

In the meantime, however, if you’re prepared to shift very slowly and carefully while the vehicle is cold, you can actually drive around this problem. Many car owners have done so for years without further problems. Not best engineering practice, perhaps, but it’s a money saver.

The answer to this will depend on exactly which model Barina you have. In some models (typically earlier ones) the code is simply a servicing reminder to make sure the owner knows maintenance is due.

But in some versions of the Barina of this era, fault code 89 usually relates to a problem with the car’s thermostat. So don’t drive it any farther as the faulty thermostat could cause the engine to overheat with catastrophic results. Have a mechanic check things out and see if the thermostat is indeed faulty. If it is, it’s a relatively cheap fix, certainly compared with the cost of a new engine.

Sometimes the code relates to a switch in the thermostat that is responsible for switching on the car’s electric fans, but either way, it could lead to overheating. Don’t ignore it in any case.

This is probably a simple case of an automatic transmission doing what it’s designed to do. In order to keep the engine in its comfort zone (and making sufficient power and torque to haul the caravan at the speed you’ve chosen) the transmission will shift through its gears to achieve that happy balance.

Any time you encounter a hill or even a headwind (and it’s more so with a heavier caravan) the transmission will assess what speed you want to hold, and then (via changing gears) keep the engine at a speed that supplies the necessary performance. Even a hot day can cause a change in the shift patterns as the transmission aims to take the strain off the cooling system by giving the engine and easier time. Again, a big, heavy caravan will amplify this effect.

However, if the transmission is changing gears for no apparent reason, then you may need to have the calibration checked and perhaps even reprogrammed. Don’t forget, though, that a modern transmission is a pretty clever piece of gear that can even choose to shift down gears going downhill to take the strain of the vehicle’s brakes. Don’t confuse an active transmission with a dud one. And if you still think the behaviour is odd, then an electronic scan of the vehicle might provide more information.