YES, allow the turbo time to slow down and cool off.
For "OUR" interest too.........how long should one idle for.....to let the turbo cool down adequately? Is it a bonus to have a "turbo-save" fitted instead........just to be safe in the long run?
Negativety and Non-enthiusiasm are the only obstacles we shouldn't encounter "
1) Pajero 2.5Tdi SWB Gen 2, 1998, JUST SOLD - 1/2014
2) Subaru Forester 2.5 XS 2017
1) Pajero 2.5Tdi SWB Gen 2, 1998, JUST SOLD - 1/2014
2) Subaru Forester 2.5 XS 2017
Nice one - wish I had that. Doing 5000km/month thus have to service every 1.5 monthssuperairborne wrote: ps. I've just found out I have another year of the Maintenance Plan on the Paj. Great bonus as I was not aware of this at the time of the sale.
How long to idle a turbo down?
How long is a piece of string?
This issue has been debated at length on the various forums. I’ll try to recall what has been said and more importantly, I’ll try to be brief.
A turbo spins at hundreds of thousands of rpm and lives in a white-hot environment. Simply put: the hot gases escaping from the engine heats up the turbo unit and the air from the intake, cools it off. It is lubricated by the engine oil, which is circulated over the turbo bearings by the normal engine oil pump.
It stands to reason that should you be running your car hard and then come to an abrupt stop and switch off the engine, that no more cool air is sucked into the unit and no more fresh oil is being fed to the bearings. The best and quickest way to cool off the turbo is to take your foot off the accelerator for as long as possible before coming to a stand still. When you come off the highway into a roadside fuel and rest centre, take your foot off the pedal as you come down the slipway. This basically stops the combustion process and considerably cooler air will come from the engine and it still sucks lots of cool air from the intake to rapidly cool off the turbo. The short period you drive, with a feather toe on the pedal, to find a shady parking spot will almost totally complete the cooling job. If you now allow the engine to idle while you make sure the windows are closed and the sunroof is shut and the youngest kid finds her shoes, you are ready to shut down and go for your comfort break. Should it not be possible to have the “slowdown” towards your stop, then a longer idle period should be allowed for.
As a matter of fact, I employ the same process and principle with my normally aspirated V6 petrol engine. I firmly believe in reducing the “heat sink” effect after a long hard run.
How long is a piece of string?
This issue has been debated at length on the various forums. I’ll try to recall what has been said and more importantly, I’ll try to be brief.
A turbo spins at hundreds of thousands of rpm and lives in a white-hot environment. Simply put: the hot gases escaping from the engine heats up the turbo unit and the air from the intake, cools it off. It is lubricated by the engine oil, which is circulated over the turbo bearings by the normal engine oil pump.
It stands to reason that should you be running your car hard and then come to an abrupt stop and switch off the engine, that no more cool air is sucked into the unit and no more fresh oil is being fed to the bearings. The best and quickest way to cool off the turbo is to take your foot off the accelerator for as long as possible before coming to a stand still. When you come off the highway into a roadside fuel and rest centre, take your foot off the pedal as you come down the slipway. This basically stops the combustion process and considerably cooler air will come from the engine and it still sucks lots of cool air from the intake to rapidly cool off the turbo. The short period you drive, with a feather toe on the pedal, to find a shady parking spot will almost totally complete the cooling job. If you now allow the engine to idle while you make sure the windows are closed and the sunroof is shut and the youngest kid finds her shoes, you are ready to shut down and go for your comfort break. Should it not be possible to have the “slowdown” towards your stop, then a longer idle period should be allowed for.
As a matter of fact, I employ the same process and principle with my normally aspirated V6 petrol engine. I firmly believe in reducing the “heat sink” effect after a long hard run.
Some okes say anything idle from 3-4minutes if you drove faster than 120km/h, 2min for about 80km/h etc. The harder you drove, the longer you have to idle.
Like Roelf said, when you idle down it gives the turbo shaft time to slow down and the turbo housing to cool down. This is important for two reasons:
1) The oil in the turbo gets burnt due to a process called "heat soak". This occurs when the turbo radiates heat to it's surrounding environment when shut down. Thus, no coolant system is running to cool down the engine/turbo, so the coolant temps spikes for 2-10min after engine shut down. The oil absorbs this high heat and gets burnt which then forms a carbon in the turbo that is harmful to the bearings, shaft and seals. Idling down allows the turbo and oil to cool down.
2) The oil in the turbo helps keep the perfectly balanced shaft's bearings nicely in place and lined up. If one should suddenly turn off the engine after high rpm's without allowing it to slow down, the shaft will come into contact with the housing at high speed and cause wear.
The lube-type turbo protector forces cooler oil through the turbo for a few minutes after engine shut down, which addresses both afore-mentioned problems.
Please correct me if I am wrong.
Like Roelf said, when you idle down it gives the turbo shaft time to slow down and the turbo housing to cool down. This is important for two reasons:
1) The oil in the turbo gets burnt due to a process called "heat soak". This occurs when the turbo radiates heat to it's surrounding environment when shut down. Thus, no coolant system is running to cool down the engine/turbo, so the coolant temps spikes for 2-10min after engine shut down. The oil absorbs this high heat and gets burnt which then forms a carbon in the turbo that is harmful to the bearings, shaft and seals. Idling down allows the turbo and oil to cool down.
2) The oil in the turbo helps keep the perfectly balanced shaft's bearings nicely in place and lined up. If one should suddenly turn off the engine after high rpm's without allowing it to slow down, the shaft will come into contact with the housing at high speed and cause wear.
The lube-type turbo protector forces cooler oil through the turbo for a few minutes after engine shut down, which addresses both afore-mentioned problems.
Please correct me if I am wrong.
Thx for all the replies!
So, my Paj and I have spent our 1st weekend together and it was bliss!
I about 350km with it over the weekend on gravel roads to the farm and back to windhoek and then again to the kuiseb river for a picnic and back. (Now you may have figured that I live in beautiful Namibia).
I was amazed how different that Paj drove on the gravel than my Ford Ranger D/C 2.5TD 4x4. The Ford was a good vehicle and I made lots pleasurable trips in it. However, (i know it's still early days) the Paj just seems better!! More powerful engine, smooth auto 'box, great suspension and a more comfy cabin. (I only miss the leather seats of the Ranger). Fuel consumption also seems quite a bit better!
At the moment the Paj is in for an executive car wash with glaze polishing, the works, to get rid of some minor scratches and the carpets well cleaned.
A good Pajero week to all!
ps. I'll post photos soon!
So, my Paj and I have spent our 1st weekend together and it was bliss!
I about 350km with it over the weekend on gravel roads to the farm and back to windhoek and then again to the kuiseb river for a picnic and back. (Now you may have figured that I live in beautiful Namibia).
I was amazed how different that Paj drove on the gravel than my Ford Ranger D/C 2.5TD 4x4. The Ford was a good vehicle and I made lots pleasurable trips in it. However, (i know it's still early days) the Paj just seems better!! More powerful engine, smooth auto 'box, great suspension and a more comfy cabin. (I only miss the leather seats of the Ranger). Fuel consumption also seems quite a bit better!
At the moment the Paj is in for an executive car wash with glaze polishing, the works, to get rid of some minor scratches and the carpets well cleaned.
A good Pajero week to all!
ps. I'll post photos soon!
2006 Pajero GLX 3.2 DiD LWB A/T, aux battery system, roof rack, tow bar, 9000 Lumen LED Light Bar, Speedo Cruise (Bestech AutoCruise)
Oh Man!
What a privilage to live there!
We are all glad (but not surprised) that you are enjoying your Pajero. Hope it keeps that way.
What a privilage to live there!
We are all glad (but not surprised) that you are enjoying your Pajero. Hope it keeps that way.
Thanks a lot! Yeah, it's great living here!! My folks are South Africans but I was born here, studied in SA, though. Nam makes for easy and quick get-aways to the bush.RoelfleRoux wrote:Oh Man!
What a privilage to live there!
2006 Pajero GLX 3.2 DiD LWB A/T, aux battery system, roof rack, tow bar, 9000 Lumen LED Light Bar, Speedo Cruise (Bestech AutoCruise)