[dinar]

Originally Posted by Sprucegoose

1 question.
If the engine is to be idled solely for the oil pump to be operating, so that the oil can be pumped into the turbo after shut down, isn't it possible to have an alternate oil pump that is battery operated.
That way when you stop, rather than idling the engine or installing a turbo timer [which means you can't engage the gear], the alternate oil pump kicks in for the required amount of time.
This can also be set up to start via remote [rather than having the entire engine fire up], so you don't have to idle before you start?

That means additional cost and a additional part that could fail.
Actually only oil cooled turbos need this idle business when switches off,if the turbo is oil and water cooled than there is no need for idling after a fast run.
Part from the bearing, the other reason for idling is that the oil cools the turbo and switch off the engine when the turbo is hot, the temperature of the internals increase and decompose the oil. Water cooling the turbo reduces the risk of over heating the oil [and turbo] when switched off after the run. A better alternative to using electric oil pump.Than there are ball bearing turbos that do not need idling as well puls have added advantage of spooling quickly .

[IndigoXLGrandDi]

The Owner's Manual of Mahindra Xylo does not Recommend to idle the Engine after Starting or Before the Engine. How is this pssible for Turbocharged Engine?
The Manual justs says "Dont Turn Off the Engine at Higher speeds. Allow the Engine RPM to reduce to Idle Rpm (may be 800-850) and then the Engine can be safely be Turned Off".

Could Experts throw Some Light on this?
I dont want to damage the Turbocharger. But am confused since the Car Manufacturer himself is Not Advising to idle the Engine after starting or before stopping the Engine.

[Sprucegoose]

Originally Posted by dinar

That means additional cost and a additional part that could fail.
Actually only oil cooled turbos need this idle business when switches off,if the turbo is oil and water cooled than there is no need for idling after a fast run.
Part from the bearing, the other reason for idling is that the oil cools the turbo and switch off the engine when the turbo is hot, the temperature of the internals increase and decompose the oil. Water cooling the turbo reduces the risk of over heating the oil [and turbo] when switched off after the run. A better alternative to using electric oil pump.Than there are ball bearing turbos that do not need idling as well puls have added advantage of spooling quickly .

Agreed, but i'm sure there are some down sides to having a water cooled Turbo, even if its water cooled, won't the engine need to be left running so that the water pump keeps running?

Suppose you don't have a water cooled turbo, then will an alternative electric oil pump be better than a turbo timer?

[GTO]

Originally Posted by IndigoXLGrandDi

Dont Turn Off the Engine at Higher speeds. Allow the Engine RPM to reduce to Idle Rpm (may be 800-850) and then the Engine can be safely be Turned Off

This statement alone is enough. You are advised to, and should, let the turbo spool slow before shutting off. I would definitely idle for a couple of seconds before driving off. And until your engine reaches its optimum temperature level (usually the mark where it stabilizes), don't high revv!

[dinar]

Originally Posted by IndigoXLGrandDi

The Manual justs says "Dont Turn Off the Engine at Higher speeds. Allow the Engine RPM to reduce to Idle Rpm (may be 800-850) and then the Engine can be safely be Turned Off".

There you go, when you reduce the engine speed to idle, the turbo has time to slow down and hence cool, plus the new generation turbos [for diesels] can handle higher temperatures.

Originally Posted by Sprucegoose

Agreed, but i'm sure there are some down sides to having a water cooled Turbo, even if its water cooled, won't the engine need to be left running so that the water pump keeps running?

Suppose you don't have a water cooled turbo, then will an alternative electric oil pump be better than a turbo timer?

Yes down side to water cooling is more line [pipe] running to the turbo and having to tap into the coolant for the engine and there are VW vans running electric water pumps circulate the coolant, water does not decompose even if it crosses a particular temperature, oil has a big issue if it crosses the specific temperature and can not be used after that.
Running two oil pumps will be tricky, cause there has to be a particular flow rate/pressure to be maintain or the turbo bearings will give away. One has to stops oil from cooking and sticking to the bearing to prevent bearing failure.
But it could be a interesting project.

[Sprucegoose]

Now we just need to find some one's turbo to test it out on
i got a 1.3 NA engine in my car, so im out of the reckoning

[tsk1979]

I usually let engine run for idle for atleast 30 seconds(if not more) before starting off, or before stopping.
The trick is simple. When I come to my apartment building, I chug along at idle. The parking etc., is done with no throttle input. This usually gives me atleast of minute of idling.
Ditto for morning start.
Start engine, wear seatbelts. adjust seats, and drive on idle till the gate, and for some time after the gate also, and then speed up.

[faridsahmed]

Originally Posted by tsk1979

for morning start. Start engine, wear seatbelts. adjust seats, and drive on idle till the gate, and for some time after the gate also, and then speed up.

Exactly the same procedure followed by myself. In addition I also take some time to select my mp3 cds . This also gives the required time to the security guard (an old guy) to open the gates.
Tata Vista QJD manual does specify idling before start/stop of engine.

[IndigoXLGrandDi]

Originally Posted by GTO

This statement alone is enough. You are advised to, and should, let the turbo spool slow before shutting off. I would definitely idle for a couple of seconds before driving off. And until your engine reaches its optimum temperature level (usually the mark where it stabilizes), don't high revv!

But I am confused since M&M has not given in the manual that the Engine should be Idled after Starting and Before Stopping the Engine.
Does this mean that M&M is CONFIDENT Enough that the Turbo can Withstand (and does not Damage the Turbo Bearings) Even If the Engine Is Not Idled after Starting and Before Stopping the Engine?
M&M has Warned that Before Stopping the Engine allow the Engine Rpm to come at Idle Rpm. Thats it.
Hence want to be Cautious. But currently I am not Idling in case of Xylo but Compulsorily on Indigo LS (IDI Engine) and Indigo XL (DiCOR Engine).

[faridsahmed]

Originally Posted by IndigoXLGrandDi

But currently I am not Idling in case of Xylo but Compulsorily on Indigo LS (IDI Engine) and Indigo XL (DiCOR Engine).

Its better to be preventive. Even if M&M have not specified still IMO idling for a minute after Start/Stop should not be a problem.
As we all have learned in schools "prevention is BETTER than cure"
Why take a chance ?

[trrk]

Hi,

How much shorter would be the turbo's life if the idling process is not followed in a car with a turbo charged engine?

[GTO]

Originally Posted by IndigoXLGrandDi

But I am confused since M&M has not given in the manual that the Engine should be Idled after Starting and Before Stopping the Engine.

What have you got to lose? If you want to be on the safe side, let the turbo come to idle rpm before switching the engine off. We have sufficiently commented on how avoiding this practice can indeed lead to premature turbo damage.

[IndigoXLGrandDi]

GTO,
For Xylo, I Allow the Engine Rpm to come to Idle Rpm (Tacho Indicated) and the Car to Complete Stop before switching the Engine Off.

As for Indigo, can I follow this Practice or is it better to idle the Engine for 30 sec after starting & before shutting it off? I use Castrol CRB Turbo SAE 15W40 API CH4 as against the Tata Motors Ltd Recommendation of SAE 15W40 API CF4+. And I Replace the Engine Oil at TML Recommended 7,500kms and 10,000kms for Indigo LS (May 2004, 1,76,000+kms) and Indigo XL Grand DiCOR (May 2007, 90,000kms+), respectively.

[nitrogary]

Originally Posted by IndigoXLGrandDi

GTO,
For Xylo, I Allow the Engine Rpm to come to Idle Rpm (Tacho Indicated) and the Car to Complete Stop before switching the Engine Off.

As for Indigo, can I follow this Practice or is it better to idle the Engine for 30 sec after starting & before shutting it off? I use Castrol CRB Turbo SAE 15W40 API CH4 as against the Tata Motors Ltd Recommendation of SAE 15W40 API CF4+. And I Replace the Engine Oil at TML Recommended 7,500kms and 10,000kms for Indigo LS (May 2004, 1,76,000+kms) and Indigo XL Grand DiCOR (May 2007, 90,000kms+), respectively.

you are much better off to let the engine idle with no load. at idle, the turbo is not spinning so fast.. maybe 15-20k rpms...
but to let the engine idle after you start and before turn off, has a few other advantages as well.
turbo is not the only place an oil film needs to be matured, in fact the same logic holds true for main bearings, con rod bearings, piston pin lubrication as well as valve train.
it will accelerate the wear for all these components. without oil at correct operating temperatures and in sufficient quantities at all these locations, you are going to lose significant performance

PS: the current xylo and bolero VLX engines are similar. you ll see the sticker on the bolero. so you can safely assume the same for the xylo engine too.

cheers
nitro

[mercedised]

I always IDLE my car for about 1min before starting off, and then for first 4-5kms till the engine reaches its optimum tempreature, I drove it under 2K RPM.