Small displacement turbocharged engines are getting increasingly popular on our roads. With tougher emission norms & fuel-economy concerns worldwide, the trend is only expected to grow. Nearly every diesel car in the market is turbocharged now. Turbo-petrols will also be commonplace soon.

Team-BHP lists some fundamental steps toward caring for your turbocharger. This is important as we keep hearing about premature turbo failures these days. Turbo's aren't cheap to repair or replace either; the bill can run anywhere between Rs. 50,000 - 2,00,000!

While engines usually have an rpm limit of 5,000 - 7,000 rpm, turbos spin at up to 150,000 rpm! In turbo-charged cars without intercoolers, temperatures can shoot over 150 degrees C. Did you know that inertia keeps the turbo spinning even after you switch the engine off? A hot shutdown is one of the top reasons behind turbocharger failure. All the mass-market cars have oil-cooled turbos where the oil dissipates heat and prevents damage to the bearings inside. There's also the issue of heat soak from exhaust gas. The worst thing you can do to your turbo is switch the engine off immediately after a hard run.

HKS - a top Japanese manufacturer of turbochargers - has this to say:

"The number one cause of turbo failure is oil "coking". Oil "coking" occurs when a turbocharger is not properly cooled down and the oil that normally lubricates the center cartridge heats up and forms solidified oil deposits."

That burnt oil eventually goes on to block passages.

Some folk insist that modern water-cooled turbos don't require a cool down period after a drive. While they are partially correct, remember that the national engines of India (Fiat's 1.3L MJD & Renault-Nissan's 1.5L DCi) are NOT water-cooled. Yes, nearly all of the mass market cars have conventional oil-cooled turbochargers. It's only some premium cars (not all) costing over Rs. 15 lakh that employ water-cooled blowers. Even then, it doesn't hurt to let that Mercedes turbo cool off for a minute after a hard drive. Further, not all turbos are built equal. If your turbo is fragile because of cost-cutting or design defects, it's all the more vulnerable to premature wear. At the end of the day, it's only a matter of 30 seconds. While there are a lot of valid arguments supporting the cause of idling, even the naysayers will agree you've got nothing to lose by practicing the idling rule.

Abusing your turbocharger can affect its longevity. With time, the turbo will become less effective. Take care of your turbo so that it gives your engine adequate boost and thus, an enjoyable driving experience for years to come.

Next Page >

When Starting Off (especially in the morning):

• Let the car idle for 30 (minimum) - 60 (maximum) seconds before you drive off. Use this handful of seconds to set the right playlist, climate control, mirrors and seat position.
• Be gentle to your car when she's cold. Maintain a low rpm level (below 2,000) until the engine has reached operating temperature. This warm-up period isn’t just good for the engine & turbo-charger; gradual warm-up is also beneficial to other components (transmission, brakes, tyres etc.). The procedure is recommended for naturally-aspirated cars as well.
• Alternate method: Crawl out of your parking spot and through your neighborhood at just over idle rpms. Diesel cars move easily with zero or minimal accelerator input. Stay below 2,000 rpm, but don't lug the engine.
• If you are making several short trips (bank, groceries, errands), pre-shutdown idling can get annoying. In this case, keep the rpm level as low as possible on the drive (without lugging the engine).

At the end of your Journey:

• For the final km or so, reduce your speed and completely avoid high rpms. Keep the revvs low ( 2,000) when you approach your destination. Not a big deal as even small cars touch 60 - 80 kph at 2,000 rpm.
• Let the car idle for 30 seconds if you've had a relaxed drive or followed the cool down procedure explained above. On the other hand, if you have a heavy right foot, idle the car for 60 seconds before you shut the engine. Use these seconds to switch off the music system & climate control, and fold in the ORVMs.
• Some ignorant drivers revv their turbo-charged car (in the parking spot) just before turning the engine off. As an informed car owner, you shouldn't.

Related Points:

• Never overshoot an oil change interval. Stick to them with discipline. Bad oil damages your turbo.
• Synthetic oil offers superior lubrication & cooling properties to your engine & turbo-charger (over regular mineral oil).
• Don't drive around with a dirty air-filter as it'll have a detrimental effect on your turbo-charger.
• If you’ve taken a mid-way stop during a hard highway drive, it wouldn't hurt to let the turbo idle for an extra minute. The holy grail of reliability - Toyota - recommends up to 2 minutes of idling after continuously driving at 100 kph, as does Skoda for the Laura.
• Turbo-petrol owners : Keep in mind that your car generates more heat than turbo-diesels. The above-mentioned procedures are highly recommended for turbo-petrols too.
• If you have a heavily modified turbo setup, or want to take precaution to the next level, consider a Turbo-Timer. It helps cool down your turbo by keeping your engine idling for a preset amount of time (after you turn off the car). Still, we recommend idling the car yourself instead of adding a Turbo-timer.

Maruti, Hyundai & Tata have 2/3rds of the passenger car market. Here’s what the big three have to say.

From the Dzire's owner manual:

From the i20's owner manual:

From the Safari's owner manual:

Insightful posts from the Team-BHP Gurus:

• Ajmat.
• Dadu.
• Shazikon.

Image Credits : The pictures of this Article have been sourced from various Team-BHP threads. Thanks to BHPians for shooting & sharing them.