turbo diesel

ju_q

Hi all.
I have recently bought a ford focus, with a 1.6 turbo diesel engine. I have been told that in order to protect the turbo funtion of the engine I need to leave it idle for a minute or two after switching the engine on and again before switching the engine off. Just wondering if this is really necessary because - even though a minute sounds really short - I seem to be lacking the patience to do this!!
Thanks

Stevie Dakota

Not sure you will get a scientific answer as who really knows how long is enough, but if there car has been driven hard before being switched off then I would give it a minute, but of the last few miles of your journey are at an easy pace then a minute may be overkill, I usually give it about 15 seconds.

BlackWizard

Stevie Dakota wrote: »

Not sure you will get a scientific answer as who really knows how long is enough, but if there car has been driven hard before being switched off then I would give it a minute, but of the last few miles of your journey are at an easy pace then a minute may be overkill, I usually give it about 15 seconds.

I'm exactly the same. I'd add that I never rev the car beyond roughly 1500-1900rpm in the morning until the car heats up a bit. I find that's the hardest part to do.

Keeping a diesel below 2000 revs shouldn't be too hard to do really.

_Kaiser_

It can be if your journey takes you onto a national route (100 km/h) inside of the first 5 minutes.

Kaiser2000

Kaiser2000 wrote: »

It can be if your journey takes you onto a national route (100 km/h) inside of the first 5 minutes.

a few hundred revs over 2000rpm won't so any harm if you accelerated gently.

peasant

A turbo at full throttle spins at up to 100.000 rpm.
In spins in bearings that are cooled/ supported by the engine oil.

Wen you turn on the engine, it takes a while for full oil pressure to reach the turbo bearings. When you turn off the engine, oil pressure and oil flow stops immediately. If the turbo is still spinning at that point, the un-oiled bearings will suffer.

So in order to go easy on your turbo do not do the following:

Do not blip the gas immediately on start up, not not rev the cold engine like an eejit

When shutting down make sure the trubo has been given a few seconds to spin out from high rpm (the time it takes to undo your seat belt and gather your belongings is long enough)
When you have had a particularly hard drive and the turbo is hot, let the engine idle and the turbo cool for a minute or two before shutting off.

Fatswaldo

Turbos operate at very high speed and temperature. By operating the engine at minimum revs you give the turbo bearings and other components time to warm up at startup and time to cool down when turning off. The theory is that if the bearings are left 'stewing in oil' at high temps they could coke up. If they are not allowed to warm up first the extra play could put extra wearing on the housings. If you have to park your car before you turn it off it should give enough time to cool it down because unless your one of the few 'high rev parkers' , you will be operating near mininmum revs. If you pull straight into a driveway you're supposed to give it a little while. (oil flows - cools turbo parts)

gofaster_s13

Two schools of thought on this issue,

1st- Don't rev the engine from cold and allow a cool down period before switching the engine off.

2nd- Give the engine a few revs immediatly on start up to build oil pressure quickly and also allow a cool down period before switching off the engine.

Reality- so long as your using a high quality oil and changing it at recommended intervals and not driving the car like Sebastion Loeb its not something to be worried about. People will say to leave a car sit for a minute after a hard drive but in reality you arent really cooling the turbo much by doing so as there are still hot exhaust gases passing through it and with the quality of modern synthetic oils its not something I bother with at all.

BlackWizard

gofaster_s13 wrote: »

2nd- Give the engine a few revs immediatly on start up to build oil pressure quickly and also allow a cool down period before switching off the engine.

I'm not sure about that. I don't think revving the car when there is little or no warm oil running around the Turbo is a good thing.

gofaster_s13

BlackWizard wrote: »

I'm not sure about that. I don't think revving the car when there is little or no warm oil running around the Turbo is a good thing.

There is oil flowing around the turbo seconds after you start the engine, if you put an oil pressure gauge on a modern engine you will have full pressure from almost the second you start the engine.

Lisnagry

Drive it like any other car,It makes no difference at all with modern turbos they all have water cooling around the bearing that the old ones didn't have.

It was the heat transfer to the oil that burned the oil and choked it up on the bearing and it would fail,this does not happen any more.
Oil pressure is well up before the turbo would spin,and there is enough oil there to protect the bearing after engine is swiched off.

GTE

BlackWizard wrote: »

I'm not sure about that. I don't think revving the car when there is little or no warm oil running around the Turbo is a good thing.

Just to use an example the turbo on my VW turbo diesel doesnt really start being used untill 1800ish rpm.

When I start the engine I can hear a tap head (or is it tapit?) noise for a few seconds then the oil pressurises and it goes away. Totally normal from what I read.

Idle speed on my engine is around 900 revs.
I think the point the poster was trying to make is that if you rev the engine to about 1200 revs for a few seconds then the oil will pressurise quicker, which in my experience it does. Anything more then that then the turbo starts to kick in and I wouldnt go too far past that.


Personally I start up, sort out my seatbelt, radio, satnav if Im using it and then I set off. And I wont go past 2000 rpm untill the engine has heated to about half normal operating temp. This isnt for oil pressure, its so the oil can heat up and work more efficiently. From what I read on TDI club is that this reduces engine wear and other types of wear caused by cold oil.

gofaster_s13

bbk wrote: »

Anything more then that then the turbo starts to kick in and I wouldnt go too far past that..

Turbos don't kick in they spin constantly from when you turn the key

GTE

gofaster_s13 wrote: »

Turbos don't kick in they spin constantly from when you turn the key

What I mean is that they dont spin to a possibly damaging rate (with regards to this oil pressure thing) untill about 2000 on my car. Its going full whack by then but much less so at about 1200, so the point Im making is that you can rev it to about 1200 ish to get quicker pressure if you need it without worrying of any realistic damage to it.

Still, its only a second or two that putting on your seatbelt would take up anyway so I dont see the point.

zilog_jones

bbk wrote: »

tap head (or is it tapit?)

Tappet

BlackWizard

gofaster_s13 wrote: »

There is oil flowing around the turbo seconds after you start the engine, if you put an oil pressure gauge on a modern engine you will have full pressure from almost the second you start the engine.

I know there is oil running around it. I was just talking about the oil not being warm.

If the revs are pretty low then I suppose its okay. But when someone says give it a few revs, I normally would think to bring it above 2000rpm on a diesel. So I guess this isn't what was meant.

gofaster_s13

BlackWizard wrote: »

I know there is oil running around it. I was just talking about the oil not being warm.

If the revs are pretty low then I suppose its okay. But when someone says give it a few revs, I normally would think to bring it above 2000rpm on a diesel. So I guess this isn't what was meant.

Doesnt make much differance if the oil is warm or not. We have trucks coming in here with over 800,000 k/m on them that operate on the continant and the first thing the drivers do when they start them is rev them to the redline, none of them gave any turbo trouble, quality oil and regular oilchanges are the key to Turbo longevity, not cool down or warm up periods.

BlackWizard

gofaster_s13 wrote: »

Doesnt make much differance if the oil is warm or not. We have trucks coming in here with over 800,000 k/m on them that operate on the continant and the first thing the drivers do when they start them is rev them to the redline, none of them gave any turbo trouble, quality oil and regular oilchanges are the key to Turbo longevity, not cool down or warm up periods.

oh okay. That's generally going against everything that was said on this thread then. You're entitled to your own opinion.

I'm just not willing to treat my diesel engine like that.

And I wouldn't compare a truck to a car.

Mr Benevolent

BlackWizard wrote: »

oh okay. That's generally going against everything that was said on this thread then. You're entitled to your own opinion.

I'm just not willing to treat my diesel engine like that.

And I wouldn't compare a truck to a car.

Fair enough, but most turbo problems come from using the wrong oil or waiting too long to change it. Even the OEM oil changes are too far apart for a modern diesel.

GTE

Confab wrote: »

Fair enough, but most turbo problems come from using the wrong oil or waiting too long to change it. Even the OEM oil changes are too far apart for a modern diesel.

Indeed, I have read a lot of problems that crop up on some VAG diesels coming down to (even the dealer) using the wrong oil.

gofaster_s13

BlackWizard wrote: »

oh okay. That's generally going against everything that was said on this thread then. You're entitled to your own opinion.

I'm just not willing to treat my diesel engine like that.

And I wouldn't compare a truck to a car.

What was said on this thread is old advice dating back to when mineral oil was the norm in engines, modern engines and oils do not benefit greatly from warm up and cool down periods, its not an opinion its fact.

http://www.bankspower.com/techarticles/show/30-turbo-diesel-fact-fiction