I understand the theory, and I think I do unknowingly spool down after a long motorway journey - my belief was that you should let some heat dissipate before turning off. Which I think about covers spooling down - although three minutes is a long time when you are dashing to the loo or for that desperate coffee fix. I live just off the M6 – less than half a mile if you use the Services service road so I could be at say seventy and then at a stop in half a mile or so.

My question is where is this covered in the Nissan user manual? Also could it affect your warranty if you did not follow the spooling down procedures? My car is out of warranty now - but it may help other Forum members.

Sorry to add to your workload Umbongo, could you just spell out what the spooling down procedure is - when you have a minute, please? If only for the less technically minded souls [a group in which I definitely belong along with the "retired" ], also should this apply to every journey?

Best wishes, John

Taken from Wikipedia

Turbochargers can be damaged by dirty or ineffective oiling systems, and most manufacturers recommend more frequent oil changes for turbocharged engines. Many owners and some companies recommend using synthetic oils, which tend to flow more readily when cold and do not break down as quickly as conventional oils. Because the turbocharger will heat when running, many recommend letting the engine idle for up to three minutes before shutting off the engine if the turbocharger was used shortly before stopping. This gives the oil and the lower exhaust temperatures time to cool the turbo rotating assembly, and ensures that oil is supplied to the turbocharger while the turbine housing and exhaust manifold are still very hot; otherwise coking of the lubricating oil trapped in the unit may occur when the heat soaks into the bearings, causing rapid bearing wear and failure when the car is restarted. Even small particles of burnt oil will accumulate and lead to choking the oil supply and failure. This problem is less pronounced in diesel engines, due to higher quality oil typically being specified.

A turbo timer can keep an engine running for a pre-specified period of time, to automatically provide this cool-down period. Oil coking is also eliminated by foil bearings. A more complex and problematic protective barrier against oil coking is the use of water-cooled bearing cartridges. The water boils in the cartridge when the engine is shut off and forms a natural recirculation to drain away the heat. Nevertheless, it is not a good idea to shut the engine off while the turbo and manifold are still glowing.

John, you could also fit a turbo timer like the one below.
PDF Manual for Turbo Timer R907

Attachment:

Turbo Timer R907 manual.pdf

http://www.ebay.co.uk/itm/D9a-UNIVERSAL ... 45e6675a5e

Turbo spool down Nissan manual



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Thanks Umbongo,

I now can see the need for this spooling down. I think I have always given respect to the engine if it has been working hard, and as I said earlier - give it chance to "cool down" before switching off. I will ensure that I do this properly from now on and give it the three minutes required.

Thank you, I am yet again in your debt and who knows you may have just saved me a replacement turbo.

My missus says Umbongo is a really cool name - suggests I change my name to “Rimbo - Umbongo”... What do you think?

Best wishes, John

There can only be one Umbongo - long live the king!

Rimbo hey be careful John

why Umbongo.... is it a reference to that sickly childhood fruit drink?

has to be easy for me to detect anything?

Oh Dear, oh dear,
Just what have I started here

http://www.simplyeighties.com/um-bongo-advert.php

Should I join Vandy and marksparks999 on the "naughty step"?

Best wishes, John

Oh ho, I have noticed an exclamation mark next to this post - does this mean I have offended somebody? I certainly hope not and will withdraw any comments if this is the case.

Can somebody please let me know, also my Board Index looks slightly different - am I black balled?

Best wishes, John