6 tips to protect your car’s Turbo

A few decades ago, any car with the word ‘TURBO’ emblazoned upon its rump signified something special. The eclectic mix of performance and prestige translated into instant envy, especially within the cut-and-thrust world of a typical 1980’s corporate car park.

Turbochargers have become almost ubiquitous, since. While they feature on virtually every modern diesel engine, many small-capacity petrol engines rely on turbochargers to help them deliver the required performance, economy and low emissions. Even so, many drivers are unaware that their car features a turbocharger, until failure brings forth a sizable repair bill.

HOW DO TURBOS WORK?

In simple terms, a turbocharger (or turbocharged engine) is a miniature compressor, powered by flowing exhaust gases. This makes a turbo very efficient, because it uses energy from the exhaust that would have been wasted, otherwise.

These exhaust gases enter the turbocharger's turbine housing and rotate a specially-shaped wheel, fixed to the end of a shaft by a retaining nut.

The shaft is supported at its centre by a bearing assembly and a compressor wheel is fitted to the opposite end, within a separate chamber. The compressor not only draws air into the turbocharger but also compresses it into the engine’s inlet tract, increasing the pressure, or ‘boost’.

By force-feeding the engine with air in this way, more oxygen can be burnt with the fuel. The result allows the engine to become significantly more powerful and more efficient.

Yet, a turbocharger’s turbine and compressor wheels rotate many times faster than the engine's crankshaft. This makes the turbocharger a highly-stressed component

that is also exposed to heat, which originates not only from the hot exhaust gases but from the fresh air that it compresses into the engine.

WHAT KILLS A CAR TURBO?

To protect your turbocharger against premature failure, follow these simple driving tips:

Try not to race your engine

1. When starting your car from cold, do not race the engine immediately from idle. Allow between 5-10 seconds for the engine oil to reach the turbocharger, before touching the accelerator.

Do not operate until warmed up

2. Should you let a turbo car warm up? The answer is yes. Never operate the engine under full power until the engine oil has warmed thoroughly. When the lubricant is cold, it remains thick and gloopy and cannot lubricate the turbocharger effectively.

Check your oil regularly

3. Old and tired oil cannot protect the turbocharger adequately. Therefore, do not extend the oil change interval beyond that recommended by the vehicle manufacturer.

Use the correct oil

4. Low-grade oil cannot protect the turbocharger adequately. Therefore, always use oil of not only the correct viscosity but also the correct specification. Check your owners' literature for more information and prioritise the manufacturer specification code.

Allow your engine to cool down

5. A turbocharger works its hardest during sustained high speeds. After a long motorway drive, a turbocharger might glow red hot.

Shutting the engine off immediately after a long run, such as when stopping at a motorway service station, might cause severe damage, because the internal turbine will not have slowed down sufficiently, plus the extreme heat generated may not been given sufficient opportunity to dissipate.

Allow the engine to idle for at least 30 seconds, before switching it off. If your car is equipped with ‘stop-start’ technology, disable it in this instance, should the car possess a disable button.

Do not 'blip' your throttle

6. Never ‘blip’ the throttle, prior to switching off the ignition. This makes the turbocharger’s shaft accelerate but, when the ignition is cut, you starve the still-rotating turbine of lubricant.

FAQs 

Are all cars equipped with turbochargers?

No, but they are very popular.

How do I know if my turbocharger is failing?

Worn bearings can create an audible whine. Should this be ignored, the turbo shaft can wobble. This can cause the fast-spinning compressor, or turbine wheel, to strike the internal housings, causing a scraping sound.

A worn turbocharger can also cause the engine to burn lubricating oil. This creates blue exhaust smoke.

Can I drive my car if the turbocharger fails?

Driving a car with a worn turbocharger may ruin it to such an extent that it cannot be repaired.

A damaged turbocharger can also disintegrate and, potentially, damage the engine severely.

The burning oil can not only cause the car to fail an MOT Test on exhaust emissions but it can also damage the catalytic converter and particulate filter.

Can I repair a damaged turbocharger?

As the turbine and compressor wheels spin at many tens of thousands of times per minute, they must be balanced accurately. Therefore, repair dictates special equipment and knowledge. Therefore, a DIYer should not attempt to dismantle and repair a turbocharger.

What are the turbo blanket pros and cons?

There is a wealth of companies that offer turbocharger upgrades. Therefore, consult a credible expert, who will advise on the most appropriate modifications that suit your requirements.

Should you be thinking of fitting a turbo blanket, the main advantages include protecting components around the unit from the extreme heat that turbochargers produce. They may also keep under-bonnet temperatures low, reducing the thermal stress on surrounding components.

Some producers claim that turbocharger blankets keep the exhaust gases hot, which increases the acceleration of the turbine/compressor shaft. It is also claimed that they keep temperatures down on the compressor side, allowing the air to be denser and carry more oxygen. The net benefits are claimed to be increased responsiveness and a power uplift.

As with any part, choosing a cheap blanket could, at best, not work at all. Should non-heat-proof materials be used, they could even be dangerous.

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