What to know!
What do you think of when you hear the word “TURBO”? What is the first image that comes to mind? Does it portray images typical from the Fast & Furious style street racing? Do you see Formula 1 Grand Prix Racing playing off in your mind’s eye, or is it Daytona or Drag racing? Whichever it is, you are on the right path, because all of these have one thing in common: SPEED & POWER. High-performance sports vehicles all have to do with speed and power, and this is the primary function of the turbo – to give more speed and power. Still, not only people into chasing that eluding chequered flag or impressing friends or girls are into turbos; your everyday Tom, Dick and Harry are into them too, but for quite other reasons.
In this article, we will look at the turbo with emphasis on its primary purpose, how it works, its benefits and downsides, as well as the normal maintenance and troubleshooting aspects related to it. Without any further ado, let us see what exactly the purpose of the turbo is.
Primary purpose and how it works
According to Mike Vousden (2016), the simplest way to understand the purpose of a turbo, is to understand that an engine needs to mix fuel and air to run. What a turbo do is it force more air into the cylinder, the air mixes with more fuel, more combustion takes place and this creates more power. Let us be more specific about its working.
In the Car Throttle animation of the working of a turbo, you will notice how cool air (blue) enters the compressor (1). The compressor suck air in, squeeze and heat it up, and then channels it down through the intercooler (2), which cools it down. Cooled, compressed air enters the cylinder’s air intake (left side of the cylinder). Combustion occurs within the cylinder and waste gas (red) from the cylinder exits through the exhaust outlet (right side of the cylinder). These hot waste exhaust gases blow past the turbine fan (3) and make it rotate at high speed. This spinning turbine, mounted on the same shaft as the compressor (1), spins concurrently with the compressor.
The intercooler plays an important role in all of this. Because turbos run at immense speeds and operate under huge pressures and temperatures, an intercooler pairs with the turbocharger to cool the hot air. Something else also assist in a cooling down capacity, namely the oil cooling system. This system ensure the turbo itself does not run too hot. Diesels have tougher engine blocks and simpler intakes, so they are ideally suited for a turbo, which is why most modern diesel vehicles have them.
Even though power is the key word, turbos can offer other benefits apart from the pursuit for speed and power. Fuel-efficiency is one such reasons. A turbo engine can make the same power as a normal engine while using less fuel. There are for example 1.0 litre turbo engines on the market that are more fuel-efficient than 1.6 litre engines, while both produce the same power. In the same breath, some people prefer the turbocharged V6 instead of a normal V8, or a turbocharged four-cylinder engine instead of a normal V6.
Turbos also make for a quieter engine because it muffles the sound of the intake. Woodford (2018) adds another very important point easily overlooked. Because turbos burn fuel with more oxygen, they tend to burn it more thoroughly and cleanly, thereby producing less air pollution.
These benefits does not mean that we should send naturally aspirated engines (those without turbos) to their early graves. Turbos do indeed have its downsides, especially the fact that it is yet another component (with moving parts, working under extreme operating conditions) added to a system that is already prone to wear and tear and malfunctioning. Another downside is the so-called turbo-lag. This refers to the time a turbo takes to produce positive pressure in the manifold. What you experience is a short delay in full engine response after pressing down on the accelerator. The point is, if you suddenly have to rely on that extra turbo power, it might not immediately be there because with a turbo-lag, the turbo only kicks in after a very short hesitation, so to speak.
It is as Woodford (2018) say – “There is no such thing as a perfect invention: we can always make something better, cheaper, more efficient, or more environmentally friendly.” The point is, things that are not perfect, will break and wear out and will need replacement. Do not wait until something breaks down, if you practice frequent maintenance of your vehicle’s fluids, components and accessories, you will most likely prolong your vehicle’s working life considerably.
There are several causes of turbo damage, according to the AET Turbo website. These causes are also aspects that you should frequently incorporate in your vehicle’s MAINTENANCE, and we do not refer to its scheduled maintenance but to the one you keep yourself – if ever you do so. If you neglect frequent vehicle care and maintenance, then do yourself a favour and read our article on why maintenance and care is so important. Just click here.
A turbocharger is a precision instrument and it is vulnerable too. Take note of the following that may jeopardise this vulnerability:
Oil / Lubrication
A constant flow of clean oil will have your turbo work effectively. Remember that oil is required at the correct flow rate and pressure to act as a coolant, to lubricate the thrust and journal bearings, but also to stabilise the journal bearings and the rotating shaft. That is why it is important to ensure that you regularly change the oil and the oil filter too. This will help to prevent the build-up of carbon deposits and contaminants. You do not want a build-up of these because it can cause abrasive damage to the inside of your turbocharger, thereby reducing its efficiency and causing irreparable damage over time.
Ensure that you service your vehicle’s air filter regularly, and check your turbo for loose connections or debris. What happens is that foreign objects can enter your turbocharger via the compressor or turbine inlets. This can cause impact damage and abrasion to the compressor wheels and turbine blades. Dirty or contaminated oil may also introduce foreign objects to the turbo. The oil filters will surely remove most of the foreign matter, but will it when contaminated and dirty oil is used? Using such oil can be a very costly mistake. Low quality oil can also deteriorate very fast. High engine & turbo temperatures can cause oil to break down, this produces carbonaceous (tarrying) materials that stick to the engine rings, and this can cause problems.
Leaks, Cracks & Poor Seals
If there are any leaks, cracks or poor seals between the compressor and the engine, the turbo will have to work much harder than it should to increase this pressure. This will reduce turbo boost and efficiency. Make sure to check the pipes leading to the turbo; these commonly crack over time.
Not Letting the Turbo Cool Down
This is something few people actually do. Dan Guides (2017) warns against this practice. He suggest that, after a long or aggressive drive, you should never switch the engine straight off. Rather let the engine idle for a minute or so; the reason for doing this is to allow the turbo to spool. If you do not allow for this, you will deprived the turbo of fresh oil during its spooling down session. Over time, this will cause unwanted stress on the turbo.
Apart from regular maintenance, you should also be sensitive to any of the following WARNING SIGNS when it comes to your vehicle’s turbo.
Check engine warning light
The check engine light does not only cover turbo failure; if the light goes on then check the turbo but if everything seems fine at the turbo then you will need to do further checks to see what kind of engine problem you have.
The boost gauge
Turbocharged vehicles fitted with a boost gauge, lets you know how much boost your turbo is producing. If your turbocharged vehicle does not have such a gauge, you can have one fitted. If the gauge do not show the amount of boost it used to, then your turbo is most likely in need of attention.
If you notice that your vehicle accelerates more slowly than usual, or is not capable of reaching the speeds it once could, this may be a sign that your turbo is failing.
A smoking exhaust
If the turbo housing is cracked or the internal seals has blown, oil will start leaking into the exhaust system. As the leaking oil burns off, it will produce a distinctive blue/grey smoke.
A loud whining noise
A damaged compressor wheel or a loose pipe will often make a loud, distinctive noise – something in the line of a dentist’s drill. This type of turbo noise is not good and it will require your immediate attention.
This brings us to the epilogue of this discussion. We at Steves Auto Clinic hope that you gained some useful information regarding the turbo. We also hope that this will put you in a position to identify turbo failure swiftly, but also to care for your turbo in a responsible manner. As we pointed out, a turbo is a precision instrument, and if you suspect any issues with your vehicle’s turbo, then rather have a professional work on it. If you have the expertise, then so be it, but otherwise we at Steves Auto Clinic are ready and willing to check and fix your turbo in a swift and friendly manner!
Sources consulted during the writing of this article:
AET Turbos. (Undated). Common turbo faults and how to spot them. Online available at: https://www.aet-turbos.co.uk/common-turbo-faults-and-how-to-spot-them/ Accessed on 28 July 2018.
Car Throttle. (Undated). GIF of the basics of how a turbocharger works in tandem with the engine. Online available at: https://www.carthrottle.com/post/nxprym4/ Accessed on 30 July 2018.
Guides, D. 2017. Turbo Problems, Symptoms and Repairs. Online available at: https://procarreviews.com/turbo-problems/ Accessed on 27 July 2018.
Vousden, M. 2016. How do turbos work, and how do they differ from superchargers? Online available at: https://www.carwow.co.uk/guides/glossary/how-turbos-work-superchargers-explained Accessed on 28 July 2018.
Woodford, C. 2018. How turbochargers work. Online available at: https://www.explainthatstuff.com/how-turbochargers-work.html Accessed on 28 July 2018.