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Old 26th April 2010, 22:24   #46
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Originally Posted by MileCruncher View Post
An engine or a motor is best started under zero load. Hence the guideline of depressing the clutch.
Never heard of the requirement to depress the clutch while starting. Is this specific to Diesel engines?

If the gear is in Neutral, will there still be a load on the engine?

This is a bit confusing. Can you please explain?
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Old 26th April 2010, 23:34   #47
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Default Cruze definitely needs it.

Quote:
Originally Posted by Chethan B G View Post
Never heard of the requirement to depress the clutch while starting. Is this specific to Diesel engines?

If the gear is in Neutral, will there still be a load on the engine?

This is a bit confusing. Can you please explain?
In my cruze the starter motor does not engage when the clutch is not pressed.

Now coming to your point about loading.
Diesel engines need all the battery juice on its disposal without it being diverted to turn other connected masses. When we press the clutch a lot of connected rotating masses are disengaged like the main shaft and other connected wheels of the gear box.Even when in neutral there are lot many components of the gearbox which are connected. Have a look in the net about gearbox functioning and then about clutch function.

Another reason is that battery's used in present day cars are the lightest/smallest possible with tremendous strain on them while starting. Internal cell short is a possibility if the battery is strained any further. Cell shorting even in one of the six cells will render them useless. Hence all loads are momentarily shut down when cranking the engine.
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Old 26th April 2010, 23:44   #48
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Originally Posted by drpullockaran View Post
In my cruze the starter motor does not engage when the clutch is not pressed.
Same is the case of the Getz D / Verna D - I guess it is something to do with the engine+transmission design (along with the reverse being to the left of 1st, shifting only with the lift-lever). I remember Hyundai advertising the Clutch to start as a safety feature, to avoid the car from pulling off unexpectedly.
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Old 26th April 2010, 23:58   #49
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Sorry!

I have mostly driven Petrol cars and will be buying a Diesel now. From this thread, I learnt about the precautions I have to take WRT Turbo and the importance of engaging clutch while starting.

Is there any thing else that is very important that I should know as a user of a Diesel Car?
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Old 27th April 2010, 01:57   #50
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Changing Engine oil at regular intervals (~5000 KM for mineral, 75000 ~ 10000 for Synth). Taking care where you fill in the fuel - fuel filters are costly, and so is the repair cost if bad fuel damages the fuel pump / injectors. Not over revving the engine - the power band of Diesels are pretty narrow, and the max torque is generated at pretty low an RPM so keep the shifting RPM in the torque band (my car does not seem to have a rev limiter, so this is all the more important). Can't think of anything else for now
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Old 27th April 2010, 03:22   #51
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Quote:
Originally Posted by drpullockaran View Post
In my cruze the starter motor does not engage when the clutch is not pressed.

Another reason is that battery's used in present day cars are the lightest/smallest possible with tremendous strain on them while starting. Internal cell short is a possibility if the battery is strained any further. Cell shorting even in one of the six cells will render them useless. Hence all loads are momentarily shut down when cranking the engine.
In the US any manual car will not crank, without the Clutch being depressed. Seems that it is a mandatory safety feature here.
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Old 11th December 2011, 09:30   #52
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Default Re: Turbo's and one minute idling

I have a question.

While out on the high-way, I let the Car idle during short stops ( a min or two). Ideally the turbo would not be working then, but would still be spinning. Can I floor the Car immediately?
I don't shut the Car off till the stop is going to be longer than 5 mins. Be it a fuel stop or water/leak break just because of the turbo. Please let me know the idle way.
Thanks

Last edited by Sheel : 11th December 2011 at 09:32.
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Old 11th December 2011, 10:47   #53
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Default Re: Turbo's and one minute idling

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Originally Posted by raj.barcode View Post
The cost varies from 2.5k to 8 k depending on the model you buy.
Any recommendations on which models are the best in the market? And what all need to be checked in selecting a good turbo timer?

Will it void warranty in the case of a new car?
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Old 11th December 2011, 11:36   #54
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Default Re: Turbo's and one minute idling

If the car is standing for a long time, all the oil would have drained into the sump. When you start the car after that, is the time when maximum wear takes place in your engine. Turbos being high speed devices, it makes sense to wait for a while for the oil circulation to start before bringing them into play. Similarly, if they are at high speed, it makes sense to wait for them to slow down, before stopping the oil circulation, by switching off the engine.
In industrial machinery, which is usually operated with electric power, oil circulation is started before the machine actually starts rotating. When the machine stops, there is braking, and the oil circulation is switched of only after the machine has slowed down sufficiently. There are builtin timers and sensors to achieve that.
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Old 11th December 2011, 15:36   #55
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Default Re: Turbo's and one minute idling

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Originally Posted by GTO View Post
If you switch off immediately after coming to a halt, the turbo is still spinning at several thousand rpm without lubrication.

Cooling may be one of the reasons, but certainly not the main reason.

GTO
Being a fresher to this thread, and no experience with a diesel engine with turbo, I have a doubt reading the above post, though very old. Does the turbo have to spin after the engine is switched off?
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Old 11th December 2011, 16:10   #56
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Quote:
Originally Posted by Sheel View Post
I have a question.

While out on the high-way, I let the Car idle during short stops ( a min or two). Ideally the turbo would not be working then, but would still be spinning. Can I floor the Car immediately?
Please let me know the idle way.
Thanks
Its best not to floor the accelerator before the car is in peak torque band in cars with a turbo charger. Gradual acceleration is the norm to be followed. For example my Cruze has peak torque of 32KGM at 2000 rpm but turbo starts spooling up only by 1280rpm. Even though I do know that turbo is beginning to spool up at 1280rpm it is best to gradually accelerate till 2000rpm and only then floor it after it crosses peak torque rpm. Absolutely nothing is going to happen to the turbo in computer/lambda sensor controlled cars but your dpf/exhaust system will have a tough time taking care of the extra soot.
So general advice for turbo charged diesels is to floor it only after you have crossed the rpm at which peak torque is produced.

Quote:
Originally Posted by thoma View Post
Does the turbo have to spin after the engine is switched off?
The turbo need not have to spin after the engine is switched off but due to inertia the turbo does keep spinning for a few seconds even after switching off the engine.It is this oil less period that kills the bearing of the turbo. This is compounded if the engine is switched off immediately after spirited driving. For turbo charged cars its best to travel the last half km to your destination with your foot off the accelerator which is what I religiously follow in my car. A minute of near idle engine rpm is enough to bring the
turbo down to its ideal idle rpm. Please note turbo idle rpm is not the same as engine idle rpm.

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Last edited by n_aditya : 12th December 2011 at 15:31. Reason: posts merged
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Old 11th December 2011, 23:21   #57
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Default Re: Turbo's and one minute idling

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Originally Posted by drpullockaran View Post
Absolutely nothing is going to happen to the turbo in computer/lambda sensor controlled cars but your dpf/exhaust system will have a tough time taking care of the extra soot.
So, the reason for black smoke from diesel cars (even newer ones like Cruze/ Swift) while accelerating is when the drivers floor the accelerator before the car hits peak rpm?
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Old 11th December 2011, 23:49   #58
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Default Re: Turbo's and one minute idling

Quote:
Originally Posted by CrAzY dRiVeR View Post
So, the reason for black smoke from diesel cars (even newer ones like Cruze/ Swift) while accelerating is when the drivers floor the accelerator before the car hits peak rpm?
Most of the times it is so. This is especially true for cab drivers who care zilch about the life of the engine or the best way to handle them. If you watch Indicas and Sumos and Innovas carefully you will notice black smoke only on heavy accelaration: dumping more fuel into the cylinders when the RPMs cannot rise as fast to keep pace, leads to unburnt fuel out of exhaust. That's how I understand it.
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Old 2nd April 2012, 13:37   #59
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Default Re: Turbo's and one minute idling

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Originally Posted by raj.barcode View Post
Best thing to do is get yourself a "turbo timer" and it will take care even after switch off the engine and lock your car. The engine is kept running as per designated time like 2 or 3 minutes helping the turbo to cool down. Why worry to wait till 1 or 2 minutes.

The cost varies from 2.5k to 8 k depending on the model you buy.
I want to know how this will work on an MT engine. The reason I ask is that when I park my car, I put it in gear and leave it. In an AT, this is not a problem, as you can run the engine in P mode.
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Old 2nd April 2012, 14:45   #60
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Default Re: Turbo's and one minute idling

You need to park the vehicle in Neutral with the handbrake on as most people normally do.
However, if you are constantly having to park on a sharp incline, then I can understand why you may need to leave the vehicle in gear.
In case you absolutely have to leave it in gear when parking, then there is no alternative to your waiting till the turbo timer goes off, before switching the vehicle off completely and exiting it.
This kind of beats the purpose of having the turbo timer in the first place because if you're going to be sitting there, you might as well wait for that 30-45secs - 1 minute and switch off the car yourself instead of spending 8 grand on a Turbo Timer.

Quote:
Originally Posted by pganapathy View Post
I want to know how this will work on an MT engine. The reason I ask is that when I park my car, I put it in gear and leave it. In an AT, this is not a problem, as you can run the engine in P mode.
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