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idling time at traffic signal?

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I don't know about the 15 seconds. But if I have to wait more than 3 minutes' date=' I might switch off the engine. But in our hot climate I prefer not to. But if the weather is cool, I would switch it off.

 

Ideally, you should not lug the engine. And for the Indigo probably, the ideal engine speed would be just when the turbo has spooled up adequately. 1500 rpm sounds comfortable enough.

 

FRG
[/quote']

 

3 minutes are too much, even if your company is paying for the fuel. You can keep the AC fan running to beat the heat.

 

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Idling a diesel engine is not a problem because diesel engines have a higher optimum operating temp range than a petrol engine. The efficiency of a petrol engine will reduce at higher tempratures, while that of a diesel engine was not have so much of a effect. Petrol engines reach optimum operating tempratures faster than diesels, it is to do with the fuel, Diesel has a higher combustion point while petrol has lower.

Hence idling a diesel engine at a traffic light for about a minute is ok on a diesel. but FE wise if the light stretches on for more than a minute and a half it is no use to keep idling. In turbo cars in any case you need to idle for atleast about a minute to let the turbo spool down safely.

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In turbo cars in any case you need to idle for atleast about a minute to let the turbo spool down safely.

Means do you advise not to shut off the Turbocharged Engines (Petrol and Diesel) at traffic signals to avoid the damage to the turbocharger due to lack of Lubrication when shut off at signals?

 

Arvind Sir and Anijog,

I asked different thing and you answered different.

Please answer the query which I asked above.

PLEASE DO THE NEEDFUL.

 

EDIT:

Turbocharged Engines need to be run at idle rpm (AC OFF) After Starting the Engine and Before Stopping the Engine to lubricate the Turbocharger. If at signals, we turn off the Turbocharged Engines, they will not get the lubrication needed and they will remain hot and get damaged in long run.

 

Now Please answer what I asked.
sudeepd2009-04-18 14:53:35

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Sudeepd : Sorry I dont know much about turbochargers, so cant really advise.

In any case turbocharged engines are performance engines and not meant for start-stop traffic and may need to be treated differently.

 

I think sgiitk will be a better person to answer this.

 

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It shouldn't be a problem for turbo engines either. Since the engine is going to start again soon anyway and the oil will start to recirculate.

 

The problem is when the engine is shutdown for the day (or for a prolonged period) after a hard run. The turbo literally cooks itself since the hot oil hasn't been given a chance to cool down and circulate. This is why many manufacturers reccommend idling periods for turbocharged engines.

 

FRG

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Religiously follow the oil change intervals and use good engine oils. Lesser oils tend to disintegrate and gum up the turbo - as long as you have good oil - your turbo should be happy.

Idling is a waste of fuel - just drive gently when you first start (and before shutting down) the engine.dtandon2009-04-18 21:30:07

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It shouldn't be a problem for turbo engines either. Since the engine is going to start again soon anyway and the oil will start to recirculate.

 

The problem is when the engine is shutdown for the day (or for a prolonged period) after a hard run. The turbo literally cooks itself since the hot oil hasn't been given a chance to cool down and circulate. This is why many manufacturers reccommend idling periods for turbocharged engines.

 

FRG

Hey FRG I thought that the oil circulation would stop as soon as the engine is turned off and at this time the turbo may remain spinning for few seconds or min  whatever it may be..

so will this not cause high friction in the turbo?? and result in wear and hence long term damage to the engine.

 

 

does this mean when the engine is cold we may turn of the engine without waiting for the turbo to spool down??

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No No guys, turbos need to be handled carefully. That is just to say that you need to follow manufacturer's instructions.

A turbo requires Oil for maintaining its cool and also for lubrication purposes.

The Turbo when it spools up with already a thin oil film on its internals. So to imagine that the turbo is dry is wrong.

If you do 100 Kms at a brisk pace and don't let the turbo idle for a 40 to 60 secs then the heat generated in the turbo cannot be absorbed by the oil flow, hence it is advised to idle the turbo.

Again when the turbo reaches it optimum operating temp similary it has to reach its optimum shutdown temp.

This graph intersects at a particular point, it will be defintely higher temprature at this intersection but it is the recommended temperature for full load operation of switch off.

So just maintain the idling time for a cold engine and the shut down time for a hot engine.

Earlier TATA used to give specific instructions with regards to shut down on the dash of its turbo cars.

Today they dont. So obviously technology is improving, but still no harm is idling for a while before shut down.

In traffic conditions in start stop conditions less than 50 secs it seems to be a bad idea to shut down a engine.

But for stops stretching a 60 sec barrier it is good to shut off. You can restart when you have about 20 secs to the green light.

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It shouldn't be a problem for turbo engines either. Since the engine is going to start again soon anyway and the oil will start to recirculate.

But what about the circulation of oil required to cool down the turbo when shutting off at signals?

The problem is when the engine is shutdown for the day (or for a prolonged period) after a hard run. The turbo literally cooks itself since the hot oil hasn't been given a chance to cool down and circulate.

Even my point is the same. If at signals the turbo is not given chance to cool down before shutting off' date=' wont that damage the turbo in long run?

Idling is a waste of fuel
Agreed on this.

1. Can you please tell how much of Fuel is required to start the engine after shutting off in case of Petrol (MPFI), Common-Rail and Non-Common-Rail Engines, respectively?

2. Please also tell how much of Fuel is burnt if idled for 30 seconds in case of Petrol (MPFI), Common-Rail and Non-Common-Rail Engines, respectively.

Hey FRG I thought that the oil circulation would stop as soon as the engine is turned off and at this time the turbo may remain spinning for few seconds or min  whatever it may be..

so will this not cause high friction in the turbo?? and result in wear and hence long term damage to the engine.

Even I am in same confusion. But I dont think the Turbo may remain spinning after the engine is shut off.

Earlier TATA used to give specific instructions with regards to shut down on the dash of its turbo cars.

Do you mean to say on the Dash of TATA buses with Turbocharged Engines? I have seen many of these in Pune. Only the buses have instructions on Dash.

Because both of our Indigos Dash dont have sticker on dash but on B Pillar. We have the first generation Indigo (May 2004 1' date='63,000+kms). It did not have instructions on the dash but on the B pillar on the driver side.
Today they dont.
Even the Dicor XL has instructions of idling the engine after starting and before shutting off on the B pillar.

 

BUT I KNOW IT IS COMPULSORY TO COOL THE TURBO WITH THE ENGINE OIL FLOW BEFORE THE ENGINE IS SHUT OFF.

 

DT, Please answer the two ques I asked you above.
sudeepd2009-04-20 15:51:16

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Idling at a signal is a different matter - no point in shutting off the engine when you are using the AC.

And for the record - I will not respond to ANY POSTS TYPED LIKE THIS. You have been around long enough to know better. End of discussion (as far as I am concerned)dtandon2009-04-20 20:01:54

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