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-   -   Why you must practice the "Idling Rule" with Turbo-Charged Cars (https://www.team-bhp.com/forum/technical-stuff/131875-why-you-must-practice-idling-rule-turbo-charged-cars-6.html)

Didn't intend to thank you for that bad experience, instead of clicking "quote" I clicked "thanks"! :D

I have seen this trend you've mentioned with Innova drivers. I know an Innova cab driver, who always revs the nuts off of his engine before turning off. His reasoning is that he is just making sure that the battery has enough juice for the next start up by revving the alternator and engine.

Yes, during the early diesel days, they needed a glow plug to heat the combustion chamber (remember the Tempo Trax/Matador days?) and the governor needs to be injected with enough fuel to start up. All this took its toll on the starter motor and the battery.

With the advent of common rail diesel injection, glow plugs are needed only in extremely cold weather conditions. The battery doesn't have to be wrung of all its juice for a morning start! Just crank and the engine starts without a sputter or stutter.

When I explained this to the cab driver and reminded him that the Innova's engine is a common rail unit, he left that bad habit of revving! Nowadays even the Volvo, Leyland and Tata commercial vehicles come with turbochargers and common rail injection, but I just wonder how many truck drivers are aware of this! Because I often find them revving before switching off in petrol stations. Perhaps, those turbos are built to withstand that abuse? Don't know.

To be honest, I was not following this rule. But sometime back i did not feel the turbo-kick the vento normally had. I remembered that we need to idle the turbo engines before/after the journey. Started following that rule. Now the turbo works fine. Now I saw this thread !!:thumbs up

I can very well understand that sir! :D

No problem, I will accept that with a :)

But here what the driver did was at the time of starting the Engine.

The best part of this thread is that now I can tell him the right method with the power of knowledge,

regards,

bbhavan.

The BMW N2O engine does not have a water cooled turbo. It is a normal turbo with a twin scroll inlet.

The engine description is in the following link, people interested can check it out. It has an interesting comparison to the 6 cylinder in the previous gen 335i.

http://bimmerboost.com/content.php?1...N52-comparison

But still, on the topic, there would be a definte drop in oil temperature if it were a water cooled turbo

Thise turbo are much bigger and are designed for use upto 300k kms. They have much higher oil flow through the turbo too. I believe the Leyland, Tata's were turbo since BS2.

I personally have seen a leyland turbo blow in 30 mins of run with a blocked crankcase breather. it allowed pressures in the crankcase to build up and stopped the turbo from draning its oil, which lead to coking in the turbo bearing (the same kinda failure as told by GTO)

Good Topic - IMO infact, it is a good practice to idle any car for 30s or so before shutdown - reason - Engine temperature increases while we slow down and it helps the cooling down by keeping the water pump in action.

In fact, the older vehicles - [read Diesel Ambassadors of the 70s and 80s] had this issue of top hose / bottom hose giving away due to OH after a long drive if shut off without proper idling for 2 minutes or so. :thumbs up

Dear GTO,

Thanks alot for the informative post,you rock sir,

I have three points that i would like to mention:

1. Fiat MJD Engine:In the recent Past Cost of Turbo has been reduced and now the turbo cost some 22 k in maruti and so is the case with fiat's engine in other manufacturer's.
2. As a preventive maintenance i replaced my turbo to a new one after the vehicle was driven some 1lac kms,this solution may not be feasible for all as i feel that additional cost of some 20 k is not that important as car has already given you money back by efficiency so some may not prefer that,but i'll recommend that,
3. Regarding Synthetic oil yes the results are really good but at the same time once the vehicle is some 80k above driven switching to synthetic oil may lead to failure of Oil pump as normally in diesel the synthetic oil common grade is 0w40,5w40-and the oil pump was pumping 15w40,20w40 mineral oil since long therefore due to oil visicosity change - failure may result- i have seen this in about 5 cars diesel till now so would advise kindly be cautious while changing oil grade and mineral to synthetic change at higher kms,

Rest GTO - thanks for your post and information to the forum,

This is definately a very good value add,clap:
--
Thanks & Regards
Anupam00

Thanks GTO for the wonderfully compiled and brilliantly conceived article. It was quite an eye opener for me. Though I used to follow the idling funda as recommended by the OEM, I wasn't too regular in that. The main reason was that I did not know the repercussions. Now that I am armed with a lot of knowledge and wisdom, I have promised myself to religiously follow it in future.

I couldn't thank you enough. Cheers

I became aware of this when my FIL's Skoda Octavia's turbo konked. I was searching the forum for causes and learned about it. Eversince I have been following this on my Figo and have also instructed my FIL's driver about it. The Octavia's turbocharger was about 105000/- worth about 4-5yrs back.

While idling before stopping, I also realised how long 30 secs can be!

Thanks for the wonderful thread GTO. Talked to a lot of my friends about this and informed them about the same. Although a majority idle their vehicle during start up, but the shut down part was not known to most.

Do have one doubt though. I was kind of following this advice on the Tata Safari by driving immediately on starting, but ensuring that the RPM never crosses the 1500 mark during the initial 1 KM or so. But is that a safe thing to do considering I'm not sure if the turbo spools above 1500 RPM only?

Thanks a ton for what is a really informative post! -Rates the thread a well deserved 5 stars. I have a question which was on my mind for quite sometime. It would be good if someone could tell me what they think about this.

Earlier I drove my cousin's Manza and inadvertently ended up stalling the car(The car in question is the Quadrajet 90). Do stalls hurt the turbocharger too? Or since i resume cranking the engine again and drive off, there is minimal stress? In this i assume that since i resumed driving, the oil coking process can not actually begin immediately.

Can somebody explain, how do we know when the turbo charger starts working? what are the pre - requisites for it? in terms of rpm/speed/warmness ?

And pls. thow some light on the advantage of turbo charger also.

I use an innova. Pls. excuse me if it is too silly.stupid:

Search and you shall find. :)

http://en.wikipedia.org/wiki/Turbocharger

The N20 tech spec (in the link you pointed to http://bimmerboost.com/content.php?1...N52-comparison) says that the electric coolant pump "... continues to deliver when the engine is stopped and very hot or to cool the exhaust turbochargers ..." (pg 96).

So perhaps the Auto Start/Stop is not harmful for my 328i's turbo?

Thanks for the link.I went through it.

But one question. How do the driver know that the turbocharger is functioning?

Pls. explain

bbhavn

Turbo charger will be running from the moment you turn on the engine. But it will be running at very low speeds which is not enough to provide sufficient compression (technically called 'boost') to actually push more air into the cylinders. As the RPM increases, the turbo's blades start spinning faster.This inturn leads to more air being compressed and pumped into the cylinder. When the engine reaches a particular RPM, the turbo would be spinning at a certain RPM where it is providing the boost that will make noticable difference to the power generated .This is called turbo spool up. Once its just crossed this RPM, you will feel that surge of power, that push into your seat, that puff of black smoke from the car's exhaust and that stupid grin on your face !lol: