[headers]

Originally Posted by me_sid

Idealy after I park, I put the car in neutral, engage handbrakes and idle for 30-40 secs if the coolant cycle doesnt start I kill the ignition, however if the coolant cycle starts which happens most of time, particularly if I am driving with AC on,then I let the coolant cycle to end before I kill the ignition

This is one of the best ways to switch off the engine - I do it too.

OT: I like your signature - have you heard the song ?

[sriturl]

Actually Maruti recommends that Swift Diesel to be idled for around a minute after a long drive, to allow turbo charger to cool down.
Its mentioned in User manual. But I am always confused as to what is the definition of "long" drive.
Normally by the time, I enter parking lot of home/office, and the last 200 mts of both journeys being practically driven on idle, I take my stuff out, and then off the engine.

[shankar.balan]

based on the Mahindra Scorp owner manual recommendation plus endorsements from many TBHP colleagues I usually start and idle for 30 secs or so before moving and again for about 30 secs or so while parking up.
In conditions of bad traffic/ traffic jams/ long wait at a red light etc, I switch the engine off completely because I do not want to waste Fuel and add to the pollution with my Exhaust gases. In any case one is not doing huge speeds and wreaking havoc on the turbo when one is in traffic, so my guess is that since the speeds/ RPM are so low in the interminable bumper to bumper crawl/commute, that it doesnt really need to be idled for 30 secs before switching off. Most times (luckily) when the light turns green it takes atleast 15- 20 secs for one to start moving, because invariably there are several cars ahead of one, so Im able to idle atleast for 10 -15 secs before moving forward. Another thing I follow in the crawly commute, is to toddle along in 2nd or 1st gear where necessary with my foot off the accelerator since the torquey engine chugs along peacefully at slow/ marginal speeds/ low revs.
Would be nice to get some views if this kind of care is enough or am I doing something wrong which will shorten the life of my Turbo.

[supremeBaleno]

@headers, do you follow that for only your CRDi or all the cars you use ?
And what is the "coolant cycle" mentioned 2 posts above ? Does it refer to the fan coming on ?

Trust tbhp-ians to make a big deal of something as simple (atleast for non-turbo cars) as killing the engine.

[headers]

Originally Posted by supremeBaleno

@headers, do you follow that for only your CRDi or all the cars you use ?
And what is the "coolant cycle" mentioned 2 posts above ? Does it refer to the cooling fan running ?

Yes sir, i do it for almost all the cars i use.

The so called "coolant cyle" refers to the thermostat triggering the elctric fan that work and bring the coolant temperature to acceptable limits. It is a common practise in all modern semi air cooled cars. So cars such as the Palio have a single fan running at a higher speed when this trigger occurs.

Originally Posted by supremeBaleno

Trust tbhp-ians to make a big deal of something as simple (atleast for non-turbo cars) as killing the engine.

Yeah, there are many surprising facts too. A slight OT:

1. Team Bhpians do not give cars for wallet parking
2. They dont use drivers mostly to drive around
3. They [sometimes] clean their cars by themselves
4. They do NOT lend their cars even to their TBHP friends.

Well..i dont want to go overboard here..so i'll stop!

[mobike008]

Originally Posted by supremeBaleno

Trust tbhp-ians to make a big deal of something as simple (atleast for non-turbo cars) as killing the engine.

I agree. I reckon we need something to discuss to keep the addiction going on

[bblost]

Before I enter a parking area I generally switch off the AC and lower the windows. This way I can see the usually dim parking lot better and can also hear any shouts like when I am driving over someone.

I kill the lights and get the power windows up and sometimes shut down the ICE before finally switching off the engine.

Originally Posted by headers

Yeah, there are many surprising facts too. A slight OT:

1. Team Bhpians do not give cars for wallet parking
2. They dont use drivers mostly to drive around
3. They [sometimes] clean their cars by themselves
4. They do NOT lend their cars even to their TBHP friends.

Dekho magar pyar se.

[shankar.balan]

better to knock off the lights, AC, music etc etc before switching off completely IMO

Originally Posted by bblost

I kill the lights and get the power windows up and sometimes shut down the ICE before finally switching off the engine.

[supremeBaleno]

Originally Posted by headers

The so called "coolant cyle" refers to the thermostat triggering the elctric fan that work and bring the coolant temperature to acceptable limits.

Say the coolant temp is high when we are planning to kill the engine. If the fan is triggered by the thermostat, and you idle till it switches off, it would have brought the coolant temp down.

Now, what if I killed the engine before the fan completed its job ? The coolant would remain in a high temp state. What are the side-effects due to this ? Left to itself, the coolant will anyway after a period of time come down to atmospheric temp, right ?

And BTW, the fan can run with the engine off (but ignition in ON state) also. So, if you wanted the fan to complete its job, you can still kill the engine, leave key in ON state, let the fan finish its job. Atleast there wont be fuel wastage while idling.

[DirtyDan]

Heat kills turbos. It warps them, can melt them and can cook lubricants inside them causing them to cake up and fail. You turbo owners, look in your manuals and you will see that it says to idle your engine for a short time after a journey. This will bring temperatures down before shut off. If you just end your journey and shut off the motor, there is period of time where the accumulating heat of the motor which has been shut down and through which no coolant is flowing and no air flowing over the entire motor (yeah, the fan may be going) will cause a sudden increase of heat inside the bonnet and this is not good for your turbo, so say the experts. It is not a good idea to shut down your turbo diesel in traffic to save fuel. You are subjecting it to too much heat. This is not my opinion, read your manuals. It's probably there.

[headers]

Originally Posted by supremeBaleno

Say the coolant temp is high when we are planning to kill the engine. If the fan is triggered by the thermostat, and you idle till it switches off, it would have brought the coolant temp down.

Now, what if I killed the engine before the fan completed its job ? The coolant would remain in a high temp state. What are the side-effects due to this ? Left to itself, the coolant will anyway after a period of time come down to atmospheric temp, right ?

And BTW, the fan can run with the engine off (but ignition in ON state) also. So, if you wanted the fan to complete its job, you can still kill the engine, leave key in ON state, let the fan finish its job. Atleast there wont be fuel wastage while idling.

You are right. as always sir!

There is no difference - but there are some psychological affects in drinking a bottle of hot water and drinking a bottle of cold water.

How will you react on each situation? Consider the above and you will have your answer.

Regarding the fan running, yes, you are right again. It can be done and works in Marutis that I have owned - still own, not the other brands!

[me_sid]

Originally Posted by headers

This is one of the best ways to switch off the engine - I do it too.

OT: I like your signature - have you heard the song ?

@headers thanks.....well in my college days I was into pro rock music with some of the best bands in kolkata... so guess my answer is yes man I definitely do know that song by heart as most of the gigs we used to open with it.

[supremeBaleno]

Originally Posted by headers

There is no difference - but there are some psychological affects in drinking a bottle of hot water and drinking a bottle of cold water. How will you react on each situation? Consider the above and you will have your answer.

There sure is a difference between gulping hot water and cold water, but I could not make out the relevance of this in the context of our discussion.

Anyway, we can take this up offline - maybe at the next improptu meet, whenever it is.

[headers]

Originally Posted by supremeBaleno

There sure is a difference between gulping hot water and cold water, but I could not make out the relevance of this in the context of our discussion.

Anyway, we can take this up offline - maybe at the next improptu meet, whenever it is.

Biju,

Ok..the cooling system is basically a closed loop system that carries water via the water pump across the engine to absorb the heat and cool the same water via the radiator.

The water circulates and because of the air coming into the radiator while the car is in motion, the heat exchange takes place via the radiator, until a certain temperature, say 90 deg or so, .

Over the preset temperature, the cooling electric fan assists in blowing air across the radiator fins to keep the water cool..say 80 deg C or so.


Case 1:
If we switch off the engine without running the electric fan, or cooling cycle, then all the hot water in the system stays whereever and cools off naturally.

Case 2:
If we do the cooling cycle [as our friends like to call it] and then switch off the engine, we almost ensure that the water in the system is at a cooler temperature and it is now safe to switch off.

In case 2, one also ensures that any engine component that needs to be cooled is not left out. Whereas in case 1, we leave it to the efficient natural cooling process.

A point to ponder is that if the natural cooling process is so effective, then the electric fan cooling system need not have emerged in the first place.

I leave it to individuals to make their choice in switching off their engines.

[supremeBaleno]

Thanks for the detailed explanation, vikram. It did help.

Originally Posted by headers

A point to ponder is that if the natural cooling process is so effective, then the electric fan cooling system need not have emerged in the first place.

Well, I would think that the electric fan cooling system is required when the car is in motion and especially when it is running for a long duration leading to buildup of temp to such an extent that the coolant/radiator alone is not able to handle it. My doubt was only about its relevance when the car is anyway going to be switched off.

Originally Posted by headers

I leave it to individuals to make their choice in switching off their engines.

True, this is just a discussion. No one is asking anyone else to follow any particular way.

As always, my thumb rule when in doubt is to look up the car manual & go by what the manufacturer has to say. After all, who knows the car better than those who made it ? And AFAIK there is no specific switch-off procedure suggested for NA petrol cars. Atleast not seen this in the manual of my cars.

Which is why I specifically exclude turbo & diesel cars. Because with these, there are specific guidelines for idling during starting and killing the engine and it is best that those are followed by anyone using such cars.