[Jeroen]

Originally Posted by Rajith

Above logic cannot work in large scale industry.Really dont know how Turbos of these giants survives for years together.Need to check with CATs or CUMMINS team.

On ships, oilrigs and other offshore applications where I've worked with large diesels for various applications, we would always let them idle before shutting down. Not just for the turbo's but actually to have the whole unit cool down somewhat evenly. On some we did that manually, on others it was just part of the automatic shut down sequence.

Jeroen

[Rajith]

Originally Posted by Jeroen

On ships, oilrigs and other offshore applications where I've worked with large diesels for various applications, we would always let them idle before shutting down. Not just for the turbo's but actually to have the whole unit cool down somewhat evenly. On some we did that manually, on others it was just part of the automatic shut down sequence.

Jeroen

In our plant there's no body to on and off these giants.It start and supply power in seconds and stops in same manner

[Sutripta]

Originally Posted by Rajith

Not practical.Our spinning mills runs on giant muliple gensets with out any idle settings with auto start and off.

Above logic cannot work in large scale industry.

Why not (for shutdown)?

Originally Posted by Rajith

Hi,
What about Turbo charged diesel generators, which revs immediately after the power shut and stops abruptly when power comes in..
Rajith

Bad implementation.
I take it there is no walk in/ walk out with grid.
Are the gensets synchronised?

Originally Posted by Rajith

In our plant there's no body to on and off these giants.It start and supply power in seconds and stops in same manner

When to put the genset on load is a system design decision. Cost of wear/ damage to genset vs. cost of no power to plant.

However, when shutting down, this does not apply. As I said, there are two stages: run at 1500 rpm without load, and idle for sometime. Being high speed engines, these will also have an idle rpm setting. Even though the 'run at idle' setting will be there at the governor, it might not be brought out to the user control panel. However, you can always run it without load for a minute or so. (The genset engine people will instinctively say 'dont run the engine without load' etc. Tell them it is for a very short period for thermal management.)

Have a proper talk with the designer/ implementer of your Automatic Transfer Switches. Have a feeling he is an electrical person with no knowledge of engines. Handling either of the above two schemes can be easily handled by the ATS. No manual presence required.

One thing to keep in mind would be to account for a power interruption while the genset is going through its shutdown sequence.

Regards
Sutripta

PS. How giant is giant? I think the KTA tops out at less than 1MVA. (The Qs are larger but still top out at I think 3MVA.)

[sunny13]

Very informative. Surprisingly in the Duster manual this is not mentioned. The DCI 1.5 is also a oil cooled engine and we need to follow the same precautions, right ?

[StarScream]

I have one question regarding this - how come one never hears of an issue with the Innova's turbo? I mean cabbies couldn't be handling their cars with care, yet the Innova keeps going and I've never heard of an Innova turbo failure.

Does it have something to do with engine's state of tune? We all know that the Innova engine can do better but its kept in a low state of tune for the Indian market. Does that mean the turbo also operates at a lower RPM and therefore has great life? Please pardon my technical ignorance.

[Jeroen]

Originally Posted by StarScream

I have one question regarding this - how come one never hears of an issue with the Innova's turbo? I mean cabbies couldn't be handling their cars with care, yet the Innova keeps going and I've never heard of an Innova turbo failure.

Does it have something to do with engine's state of tune? We all know that the Innova engine can do better but its kept in a low state of tune for the Indian market. Does that mean the turbo also operates at a lower RPM and therefore has great life? Please pardon my technical ignorance.

Good observation. Truth is that most modern turbo engine, simply don't require cooling down any more. If it's not mentioned in the manual, its not required.

Fact is, most people other then those who follow this thread will never be aware of idling before shutting down. Hence they don't. Its not as if the streets in India are littered with engines that had their Turbo's damaged, is it? No matter what, turbo problems tend to be pretty rare on modern cars.

So if an engine is somewhat over engineered, or underused, that helps even further. Not just for Turbo wear, but all engine component wear for that matter.


Jeroen

[StarScream]

Originally Posted by Jeroen

Fact is, most people other then those who follow this thread will never be aware of idling before shutting down. Hence they don't. Its not as if the streets in India are littered with engines that had their Turbo's damaged, is it? No matter what, turbo problems tend to be pretty rare on modern cars.

No, you don't see the streets littered with cars with damaged turbos but you do hear about the odd case across brands be it cars that use the Fiat Multijet or Skoda or BMW. It just got me wondering why the Innova, in particular, is so bullet proof?

[Jeroen]

Originally Posted by StarScream

No, you don't see the streets littered with cars with damaged turbos but you do hear about the odd case across brands be it cars that use the Fiat Multijet or Skoda or BMW. It just got me wondering why the Innova, in particular, is so bullet proof?

I don't know. I have a Innova myself. In fact all our company cars are Innova's. So far no problems what so ever. I can only speak in very generic terms, but all the Japanese cars I've ever owned were reliable beyond belief. I honestly think that other than normal maintenance I ever had any other problem with any of my Japanese cars.

Extremely dull, but extremely well put together. Maybe its the Japanese way of doing so. They copy paste a lot, but make sure to copy paste only every bodies good bits, so they end up with a better overall product.

Jeroen

[Sutripta]

Originally Posted by StarScream

I have one question regarding this - how come one never hears of an issue with the Innova's turbo? I mean cabbies couldn't be handling their cars with care, yet the Innova keeps going and I've never heard of an Innova turbo failure.

Adding to what Jeroen says -
Good rule to follow, but doesn't mean that the first time you don't do it, the turbo is going to fail. Just like a bad driver doesn't have an accident every time he gets behind the wheel.

Also, in our environment, most cars do not operate at peak power for any length of time, if at all. (Peak power guzzles fuel!)

Regards
Sutripta

[adroit]

i have a questions to ask here. I am using Manza diesel and generally keep the car below 2500 RPM as my office is hardly 10 KM from home and in Delhi Traffic you generally don't get opportunity to rev the engine easily. Since i don't think i car's tubro is being used much during the drive, do you think i also need to follow the above idling Rule ?

[TheTeacher]

How practical is it to follow this rule in hopping situations? 5 minutes at one shop, 10 at another after a short drive, 5 minutes at an ATM elsewhere. Does the rule only apply to cold starts and last shutdown of the day?

[debuda]

I am told that modern car turbos are designed in such a way that even after the engine is switched off, the lubricating oil (and coolant, if applicable) continue to circulate through the bearings / housing for some time simply by natural convection. This ensures that there is no overheating and breakdown of the oil.

Nevertheless, a technically informed car lover like me will still make it a point to idle the engine for a short while before switching off, especially if one has been driving at high power. That is the reason why I keep my XUV's automatic stop-start system (Micro Hybrid) OFF during long drives. But in stop-and-go city driving I have no problems with allowing the Micro Hybrid system to stop my engine almost immediately after I come to a halt at a red light.

The majority of car users are not so conscious of the supposed perils of switching off the engine immediately after arriving at their destination, and as someone has very insightfully mentioned on this thread, the roads of this world are not exactly littered with cars with failed turbos. So it is not unreasonable to assume that the ultimate goal of good design is to make the product more idiot-proof!

[pahwa]

Thanks GTO for putting this all together. I have burnt my fingers not following these best practices of idling before and after driving. Ruined the Turbo-charger of Chevrolet Captiva due to sheer ignorance. Have seen many drivers revving the car at around 4k RPM just before switching them off. One of such drivers told me that it is good for the diesel engines



The estimate for the replacement of turbo-charger in Captiva is about 1.25 lacs INR - you can buy a decent second hand car for this price

[s_pphilip]

Again Thanks GTO, excellent thread for unsuspecting owners who would not even realize after witnessing a problem with their Turbo's, that driving habits wrecked their prized possessions.

In my case when I took the Embera crdi for a normal check up to the Authorized service station - because I saw occasional clouds of black smoke while accelerating - and parked the car to call the service adviser, in some time two of them came out, one opened the bonnet and another started the car and soon started revving the car, while the other was trying to pay attention to something, not sure what, but during this there was clouds of black smoke that spewed out of the parked car.

Later they abruptly switched off the car and told me everything is alright and the crdi does spew some smoke but I thought it is more than my liking, I don't aggressively accelerate and hence very rarely notice these clouds of black smoke, but somehow it doesn't feel comfortable.

Now the interesting thing is I asked them is it necessary to idle the car before and after revving the car and they looked at me as if I asked a stupid question and replied 'not required, won't make a difference'.

I am sure they revved above 4500+ rpms in those few minutes, now is there some preventive checks I can proactively do to ensure a healthy turbo? I wish I had read this thread as I would have insisted not to switch off.

Does that mean they too are ignorant, because I do recollect noticing a sticker next to the ignition of the Swift DDIS or Safari (not sure which) stating that it is recommended to idle the car for a minute or so, I use to idle without knowing the reasons or logic.

Another question is what happens when the engine stalls, agreed you may be crawling just before it, but still revs could be high, hence the damage could be similar, right?

Cars like Embera crdi stall quite easily if you try to crawl in 2nd gear, over time I started driving in 1st at a higher rpm, but still sometimes it does stall, the clutch needs delicate moderation.

Rating this thread a well deserved 5 stars, threads like these should get a gold rating or a super rating or something, its valuable, too valuable.

[Zahir]

Thanks for this break down. You could not have been more thorough. With more diesel cars hitting the roads everyday, maintenance & life extension should be a part of every drive. People have often told me that I've been going too far with the 1 minute rule on my car but I've practiced this on all my turbo diesels & I've never had an issue.

The way I see it is if you can shell out all that money for your car, you can shell out those extra 60 secs.