[GTO]

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.

[GTO]

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.

[GTO]

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:

[GTO]

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.

[Rehaan]

This is one of those things that doesn't hurt to do, regardless of the situation. It's good for other components of your car too.

Personally, i hate sitting in the car for upto a minute after reaching my destination. So to avoid that, I follow a simple rule which is just as effective: drive at low RPM (and low load) for the last minute of my journey. If I've been driving spiritedly, then I increase the time spent driving slow at the end.

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Intercoolers are found in some turbocharged cars. Don't make the mistake of thinking that these are for keeping your turbo cool. They are for cooling the air that comes out of your turbocharger, before it goes into the engine intake.


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For those of you who are wondering what this turbo bearing looks like and why the oil is so important: In a majority of turbochargers in Indian cars, the metal shaft of the turbo doesn't use what most people typically consider bearings (ie. ball bearings). It's just two highly smooth metal surfaces rubbing up against each other, with only a thin film of oil as lubrication in between.

You can see these 'bearings' here, shown in golden-brown:

Source

cya
R

[thoma]

Thanks GTO. Recently, we are seeing many such articles, that are a huge value addition to the forum. Though the gist of this article may lie scattered else where on the forum, it is always great to have a collated picture. Now we are becoming more of an official 'moto-pedia'.

Personally, this is the right time for me to know more on a turbo, as our family is looking forward to own our first turbo-charged diesel vehicle. In fact, it could be either one of the national engines you mentioned. We are leaning more towards the one without the inter-cooler! Dad has an innate habit of shutting down the engine as soon as the car enters our garage. Though it is a herculean task to educate my dad, with the help of print outs of this page, I guess, my job should be a bit easier.

Could you please mention the regular maintenance schedule / itinerary for a turbo-charger and its related parts too.

[SDP]

Thanks GTO for the tip and its detailed explanation.

I have gone through the earlier threads in the past and came out confused as there was no conclusion.

Turbos are precision engineered and are VERY costly in comparison with other parts of the car. It just makes sense to take care of them, even if it means spending a minute more in your car.

I have been idling before, but not after as the last 100 meters is dead slow anyways. Let me start idling afterwards as well. Prevention better than cure!

[coolboy007]

Thanks a ton GTO, articles like these go a long way in educating others about it and preserving our cars, which all tbhp'ians love. Information like this isnt passed on to common man as 90% people dont even read owner's manual. I have seen people rushing at 60-70 towards traffic lights with turbo on full spool and then switching off engine to save some fuel.

Even i didnt know about turbo idling until a few months ago as i was used to driving non turbo petrol cars but ever since Vento came in, am religiously following the 1 minute idling procedure and avoid revving up near my home. No harm in taking care of your ride how tough the turbo or engine may be.

Infact i have been educating my dad about it as well and now he also does the idling part, had to warn him about the cost of turbo replacement

[Biraj]

Thanks GTO, this is really useful. There have been conflicting opinions shared on the forum on whether or not, one should idle the car. I do it, because it doesn't cause any damage. If one is already driving a turbo-charged petrol how much damage would petrol worth one minute do? Moreover, just being patient for the first and last 60-90 seconds of the drive can save many hours of anxiousness that a failed turbo can cause.

Ever since I got the T-jet, I have been trying to follow this rule religiously. I remember a moment when I shut the car off immediately after a long drive and then instinctively switched it on to idle for one minutes. Then I was puzzled, did I do more damage than damage control?

[subratasenn]

Thanks GTO, I have the habit of idling my car before I start off, but never bothered about idling for even half a minute after reaching my destination. I must change this habit. I hope at 7500 km on my ODO it's not to late to begin!

[soonya]

Thanks GTO for the advice. Irrespective of the type of car or bike I do have the habit of idling them for about a minute. Typically I start the engine, open the gate, put my stuff in or do a last minute check if I forgot anything. Same after I pull the car in to the parking place, I shut the gate take out my things from the car and wait till I hear the fan cut off and hear the car idling. All this to get over the impatience of waiting and doing nothing

However on another thread where I read that it is recommended to switch off engines at the traffic lights to save fuel. It was also argued that modern cars do not waste fuel on restarting the engine. Does it not sound contradictory to this thread? I am a bit perplexed.

[MetalBuff]

Hello GTO,

Thanks for having this valuable information for us.

Have read contrasting opinions on T-Bhp but, finally this should put a logical end to those discussions that ideally one SHOULD idle pre and post driving. Doesn't hurt to do that unless someone likes being slapped with heavy bills

Even though it didn't make sense to me previously (that is, while going through the previous discussions. That said, your post is fairly detailed and provides both logical and technical explanations ) and my Esteem lacks a turbo, I have now inculcated this habit. After going through your post, glad I did!

As they say, better late than never.

-Shivang Gandotra

[amolpol]

A noob question - would basement parking allow for suitable time to cool down the turbo and keep it lubricated? Typically one has to stop and reverse their car in the tight spots which is done at idling rpms. I ask this coz I haven't been idling before shutdown as religiously as I do at startup.

[rohanjf]

Very nice article. You have put together all bits and pieces discussed in various threads, plus a whole bunch of new information. Thank you!

Perhaps what I do during short breaks on highway trips would help others. I carry both car keys of my Palio Stile SDX. I always keep the second key in my pockets. When I stop for 2-3 minute breaks (you know for what), I park the car on flat ground, keep the engine running on idle, engage hand brake, lock the car with the other key and do my business. On my usual trips between Bangalore and Mangalore, I do not switch off the engine even once.

My Palio with its age old technology lets me lock the car without switching the engine off. I hope even newer cars with cental locking allow that.

[SDP]

Originally Posted by soonya

...
However on another thread where I read that it is recommended to switch off engines at the traffic lights to save fuel. It was also argued that modern cars do not waste fuel on restarting the engine. Does it not sound contradictory to this thread? I am a bit perplexed.

Its not really contradictory. The point on the other thread is about fuel-wastage on startup and is true about all cars. The point on this thread is about life of the turbo and applies only to cars with turbo-charged engines.

So for turbo-charged engines, one should wait for 30-60 seconds after stopping at a signal before thinking about turning off the engine.