Nissan Pulsar Engine Problems

This sounds a lot like a faulty ignition barrel or an electronic key that has a semi-flat battery. A worn barrel can often prevent the necessary contacts meeting to complete the ignition circuit and, likewise, an electronic key without sufficient power can also give these symptoms as it struggles to enable the ignition. This can be a very hit and miss thing, which is just how you've described it.

So check the condition of the battery inside the key and perhaps the condition of the car's battery as well. If the situation gets worse, a trip to the auto electrician is probably in order. At least your STS model has a relatively conventional ignition key set-up, rather than the push-button, proximity key of the SSS model which brings another layer of complexity to this function.

Modern engines rely on a raft of sensors to inform the computer of what’s going on under the bonnet and what needs to be adjusted to keep the thing running smoothly and efficiently. A car that is using too much fuel and stalling could be having a problem with the sensor that tells the on-board computer that the engine is up to operating temperature. A cold engine needs more fuel to run properly so, if the sensor is telling the computer that the engine is still cold, the computer will continue to inject extra fuel into it. Of course, if the engine is up to temperature (regardless of what the sensor says) that extra fuel will show up as increased fuel consumption and could easily make the engine stall or run roughly.

However, that’s just one possibility and with the dozens of sensors dotted around a modern engine, the best advice is to have the car electronically scanned to see what fault codes are thrown up. The good news is that these sensors are usually inexpensive to replace and should return things to spot on pretty much immediately. Other suspects would be oxygen sensors and maybe even the stepper motor which controls the idle speed.

If the gearbox won’t shift gears, then the vehicle won’t be able to accelerate any further once the engine has reached its maximum speed in the gear in which it’s stuck. That’s probably (I’m guessing) why the car feels like it won’t go any faster.

There are any number of reasons for an automatic gearbox to remain in one gear and refuse to shift. They start with low transmission fluid and go all the way up to a major internal failure or even a computer-related problem. There’s no real way to diagnose these possibilities remotely, so you really need to get the vehicle to somebody who specialises in automatic transmissions and get them to take a close look and diagnose the problem.

If it’s a major problem with the gearbox, your decision then becomes one of whether the vehicle itself is in good enough condition to warrant spending the money. A major job such as a new transmission and the labour to fit it could easily wind up costing more than the car is worth. Sometimes you’re better off scrapping the vehicle, cutting your losses and moving on to something newer and safer.

If the noise sounds like a dull thud or knock from deep within the engine, then I have bad news. Something inside the engine is probably trying to get out. And if it does, the engine will be instantly turned to junk. The worse news is that it probably already is (junk) even though it’s still running, because the damage has already been done. From the sound of things, your engine is perhaps only a few seconds away from exploding expensively.

Noises like this are usually caused by wear in the bearings – typically the con-rod bearings – and while they can be fixed if you do so before the engine grenades, it will always be an expensive job. In fact, it would likely cost more than the actual value of a 2005 Pulsar itself.

The best advice, then, is to let a mechanic have a listen to see if it’s as bad as you’ve described. From there, I reckon a second-hand engine form a wrecked Pulsar would be your best bet if you’re determined to keep the car.

It could be an air leak, or an incorrect idle setting. Have a mechanic check it.

You would like to think it would last the life of the car, but there are many reasons it might need replacing.

It would be worth having a mechanic check it for you. It could simply need a tune up, new plugs, plug leads, clean of the throttle body, or idle adjustment.

It could be the battery; it could be the fuel pump. I had a similar problem that turned out to be a blown head gasket, so it could be worth doing a leak test.

It could be a fault with the computer, but I would have it investigated rather write it off as a computer glitch. You could have a problem with the cooling system, so I would have a mechanic investigate it.

It’s mounted at the inlet of the intake manifold.