Frankly, about a thousand different things. Poor idling and performance can be down to the ignition system, fuel system or mechanical wear or problems anywhere within the engine. And within those three things can lurk potentially thousands more reasons for poor running.

A mechanic familiar with this make and model is your best bet. They will probably start with the basics such as fuel supply and quality, spark strength and timing and a compression test to make sure all is well within the engine itself. This is a case where it’s important to go back to first principles of fuel, spark, compression and then start to look at the more intricate systems that control the engine.

Honestly, though, it could be anything from a dud sensor in the intake system, the same problem with the cooling system (not allowing the engine to reach full operating temperature) or even something mechanically fundamental like a blocked catalytic converter, dirty filter or slipped camshaft timing. Or a multitude of things in between. A good workshop will be able to sort it, however, without simply swapping parts that may or may not be the problem.

It’s important to differentiate smoke from water vapour when it comes to problems like this that may not be a problem at all. Given you’re also seeing water being emitted from the tailpipe, I’m tipping that this is all happening when you first start the car in the morning.

The fact is, this is perfectly normal behaviour from a conventional engine and is simply the engine doing what it does. The water and water vapour is visible on these colder mornings we’re experiencing right now in Victoria because the exhaust isn’t yet hot enough to turn it to steam (steam is actually invisible, water vapour is the white mist you can see). As the car warms up and the exhaust gets hotter, it will turn the water into steam and you won’t notice it.

But how does the water and vapour get into the exhaust in the first place? Believe it or not, water is a natural by-product of burning petrol in an engine. And until the engine and exhaust are hot enough to turn that water to steam, it’s visible to the naked eye. Which is when a lot of people start to get worried. But they needn’t, as it’s nothing to be concerned about.

The flip-side is if the tailpipe is actually emitting white or blue-ish smoke, at which point you potentially have a worn or damaged engine. This will happen regardless of whether the engine is hot or cold and it won’t go away once the engine is warmed up. If that’s the case, you need to have the engine compression tested by a mechanic as the first step towards finding the cause.

It all depends on what you mean by faulty. If the rack has wear in it and isn’t as tight or responsive as it should be, then it will continue to wear out further (and eventually fail) but shouldn’t affect the car beyond that. If, however, you mean the rack is dangerously loose or about to break or come apart at some crucial point, you stand to destroy the car in a crash and perhaps injure yourself or someone else. Or worse.

Fundamentally, there’s no margin for error with a car’s steering. If it’s not right, the car should not be driven at all and should be fixed properly before it hits the road again. Provided you can find a second-hand steering rack with no wear and in perfect condition, then it should be fine to use. But again, don’t take chances with any of this. And make doubly sure there’s no damage to the rack and its fittings such as from a previous crash. Ask yourself why the original car donated this second-hand steering rack in the first place.