Turbochargers

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According to this article you need to idle your engine before switching it off, but I fought that was only for old cars.

https://www.iol.co.za/motoring/indu...hat-will-kill-your-cars-turbocharger-26811650

"One big rule


“Allow your engine to idle for a short while to stabilise temperatures before shutting off the engine, or drive the last few kilometres of your journey slowly, ‘off boost’, to allow air flow to start to cool down the engine and turbo before you arrive at your destination. And, finally, replace the oil feed line at specific intervals depending on the vehicle make and application,” Kambouris says."
 
as far as i know, fans and pumps still carry on if the turbo is hot....
besides. cars all stop/start these days
 
So with turbocharged aircraft you need to plan your descent and gradually reduce power as you descend, reducing manifold pressure gradually until you reach your target speed and begin the approach, once on the ground if the taxi to parking is short you need to idle the engines for about 5 minutes to circulate oil through the turbos as they spins down

The same reason applies for the descent, you don't want major power reductions and oil pressure changes going through the turbo, spinning them up is easy, slowing them down not so much

As these engines are essentially the same as older car engines I'd assume the same rationale applies - modern cars with computer controlls may be quite different however

Talking to charter operators you can actually see whose aircraft engines last to their overhaul time VS those that don't purely by how their crew handle the engines, and how many different pilots fly an individual aircraft
 
I’ve never let my car idle after a hard run, but always did the thing of driving a bit more calmly the last kilometre or so, but I’d apply that logic to even an N/A car.

200,000km on original turbo.
 
SauRoNZA said:
I’ve never let my car idle after a hard run, but always did the thing of driving a bit more calmly the last kilometre or so, but I’d apply that logic to even an N/A car.

200,000km on original turbo.
Click to expand...
I do this as well!

I still have wonky actuator in turbo for 9 months now. Issue is that the actuator can't be replaced, the entire turbo I needs to be replaced. This came from Audi, other mechanic and 2 different turbo companies.

That said, both turbo companies told me if the turbo is running fine, no noise, no smoke, no loss on power, it's very likely either the voltage sensor on actuator playing up, or it is jittering a bit. Either way, 9 months on no issues except for stupid warning light on dash. Stupid car!
 
The only time I let it idle down for a bit is when I stop at an Ultra city off the motorway just to let things slow down a tad after a long run at speed.
My understanding is that the watercooling and smaller sizes have done away with the need for a sustained idle down and that sensitive engines have an oil accumulator on the turbo to feed it oil after the motor has switched off.
 
Turbo chargers do not take forever to spool down. They are in fact constantly spinning, the speed at which they spin is proportional to the volume/speed of exhaust gas exiting the engine.

Low engine speed, low speed turbo spin.

High engine speed, high speed spin.

The problem with turbo chargers are the amount of heat they make. The 'cool down time' that is suggested is let the engine bay temperature normalize. This minimizes heat soak, and heat soak can damage the compressor and impellor housings, the balance shaft, heat up oil past its temp range and burn it(this leave carbon deposits which can screw up the oil seals and bearings).

At least, this is the case with cars. Modern turbos are not that much different from the turbos of days gone. The control interfaces are the same, they have just been improved.

There have been major leaps forward have been in the cooling and electronic areas.

Dad and I built a few aftermarket turbo cars, including a carb'd, non-intercooler Kent powered Esky. This was a fun little monster. No one could figure out why it worked reliably.
 
Last edited:
SauRoNZA said:
I’ve never let my car idle after a hard run, but always did the thing of driving a bit more calmly the last kilometre or so, but I’d apply that logic to even an N/A car.

200,000km on original turbo.
Click to expand...

I do the same. and when I didnt have a chance to slow down (lets say a spirited drive with mates, then suddenly we pull over for pics). then I do idle. despite knowing pumps and stuff typically carry on.... that said its like for 2 mins max
 
SauRoNZA said:
I’ve never let my car idle after a hard run, but always did the thing of driving a bit more calmly the last kilometre or so, but I’d apply that logic to even an N/A car.

200,000km on original turbo.
Click to expand...

Nice, what ride?

I'm about to hit 185 000km on my fiesta
 
SauRoNZA said:
I’ve never let my car idle after a hard run, but always did the thing of driving a bit more calmly the last kilometre or so, but I’d apply that logic to even an N/A car.

200,000km on original turbo.
Click to expand...

I do similar but will let my car idle for a little bit after stopping even though it has electric pumps for when the engine has been shutdown.
 
i always idle the car for +- 1 min after driving to let everything cool down and not "shock" the system.
 
I think warming your car up properly way more important before spirited drivign. Too often people just check the "temp guage".

I wait for my oil temp and gearbox oil temp to be correct. The Oil temp will give it the right viscosity and performance, which means a ton to your turbo.

I also use my turbo boost guage, because that defines how hard its working. you could very easily boost at low speeds, low RPM under load
 
This article is for people that "get in and drive"

Kris is also just giving generic advise. It is not bad per se. But it is not technically accurate.

Don't take motoring advise from IOL motoring.
 
I found that report on IOL very surprising when I first read it. If you have a car that is older than 10 years then it is sound advice to let the turbo cool down by idling the vehicle for a minute or two.

However, on modern cars the turbos are designed in such a way that oil is still circulated in the turbo after the engine has been shut down. This makes it totally unnecessary to idle the car.

nazmo said:
I think warming your car up properly way more important before spirited drivign. Too often people just check the "temp guage".
Click to expand...

That is old school thinking - in fact it is now believed that you can cause your car more harm by idling it to warm it up than to pull off gently and driving carefully for the first kilometer or so.
 
Freddl said:
I found that report on IOL very surprising when I first read it. If you have a car that is older than 10 years then it is sound advice to let the turbo cool down by idling the vehicle for a minute or two.

However, on modern cars the turbos are designed in such a way that oil is still circulated in the turbo after the engine has been shut down. This makes it totally unnecessary to idle the car.



That is old school thinking - in fact it is now believed that you can cause your car more harm by idling it to warm it up than to pull off gently and driving carefully for the first kilometer or so.
Click to expand...


Read my post.. I said spirited driving.

You dont hammer your car to power peak until the oil temps are up. More advanced cars even limit power/rev range when cold.
 
Freddl said:
That is old school thinking - in fact it is now believed that you can cause your car more harm by idling it to warm it up than to pull off gently and driving carefully for the first kilometer or so.
Click to expand...

No, that's actually all about emissions since catalytic converters don't work until they are warmed up and therefore the environment is actually polluted more in those first few minutes while they are cold than the entire leaded petrol thing ever did.

That being said the "American" concept of warming up where the car is left for 10-20 minutes outside idling is not a good idea.

But the reasonable person's logic of letting the car idle for a minute before setting off is not going to hurt anything and only offer benefits. (Emissions aside of course).
 
Freddl said:
I found that report on IOL very surprising when I first read it. If you have a car that is older than 10 years then it is sound advice to let the turbo cool down by idling the vehicle for a minute or two.

However, on modern cars the turbos are designed in such a way that oil is still circulated in the turbo after the engine has been shut down. This makes it totally unnecessary to idle the car.



That is old school thinking - in fact it is now believed that you can cause your car more harm by idling it to warm it up than to pull off gently and driving carefully for the first kilometer or so.
Click to expand...

What happens if you got a old car with a new turbo :sneaky:
 
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