With the ever-increasing drive towards performance vehicles and power-house cars that look and sound like speed-machines, turbochargers have become something of a regular topic these days. In my younger years I drove a pre-owned sports car whose turbo, on day two of belonging to me, started choking out billows of white smoke. I soon took an expensive class in turbocharger troubles, and here is what I learned…
Turbochargers work by using waste gasses from the exhaust to drive a turbine, which spins an air compressor that forces more air and oxygen into the cylinders, enabling them to burn more fuel and produce more power. Naturally, the turbo can be damaged and cause major problems in your vehicle.
There are various things that can cause damage to a turbo, the first of which is the build-up of carbon deposits and contaminants that are abrasive to the inside of the turbo. A constant flow of clean oil is required to keep it functioning optimally, and as such the oil and oil filter should be changed regularly. Similarly, small particles, debris and leaves can enter the turbo through the compressor or turbine inlet, leading to damage. Servicing the air filter regularly and checking for debris will ensure this doesn’t happen. Leaks, cracks or deteriorating seals between the compressor and the engine will make the turbo labour harder than it should, which could also damage it. Other causes included excessive exhaust gas temperature, moisture ingress, wear and tear and exhaust system problems can cause damage to the turbo.
What to Watch Out For: Your vehicle will give various symptoms when it is time to check your turbo, the first of which (on most modern vehicles) will be the illumination of your engine fault light. If your vehicle is fitted with a boost gauge (which indicates how much boost your turbo produces), you may notice that there isn’t as much boost produced; this is usually a sign that your turbo is in need of maintenance. Similarly, if you notice your vehicle accelerates slower than usual or struggles to reach the speeds it did in the past, your turbo may need repair or replacement. If you notice clouds of smoke behind you, as in my case, this could indicate a cracked turbo housing, blown internal seals and resulting oil leaks which produces a thick blue-grey smoke (especially when increasing revs). A final tell-tale sign is the distinctive turbo whistle when you accelerate which could mean a compressor wheel is damaged and your turbo needs some attention.
Never ignore any of the signs above; you may be able to get away with simple maintenance or repair if you pay attention and react sooner rather than later. If you leave a damaged turbo as is, and continue driving the vehicle, you will most definitely find yourself having to replace it – usually at quite a cost. When it comes to replacing this specialised part, you have the option of buying a whole new turbo or finding a reconditioned turbo – which simply means the internal components have been cleaned out and maintained and put back together again. The price difference between the two can often be quite major, although both options run into a few thousand rands each.
By Desh Bechan