924Board.org

[Aussie931]

Does anyone know how legit the idea of letting your car idle before you shut it down to reduce turbo failure is?

Wouldn't it be better to just make sure that you take it real easy for the last few minutes before you get to your destination?

I would have thought that if you let the car idle while it is stationary, the lack of air flow would actually cause the engine temp & hence oil temp to increase. It would take quite a few minutes of idling, and a cool day for the temp to actually drop whilst idling with no air flow.

thanks
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1979 Series 1 924 turbo

[Per]

[dwak]

I am familiar with this situation from using turbo diesel construction equipment but I believe newer turbos have solved this problem in various ways. I know a few who have a delay switch that leaves the motor running for a few minutes after you switch off. I wonder if after market turbos solve this problem or whether you could have a delayed fan set up for the cooling period but I guess that wouldn't help the flow of oil.

dwak
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2x924NA's for parts
931
924S

[Khal]

My two cents? Yes, on the 924 Turbo's you should warm them up before use and idle them down after hard use.

In fact, I'd argue that you should let any engine get up to temp. before you use it.

But if you're using modern oil i.e. Mobil 1, then it probably isn't absolutely necessary.

Still, I use Mobil 1 in mine and I always try to warm it up and idle it down. It's just good practice, IMHO.
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'80 924 Turbo

[dwak]

Khal,
Don't you find that Mobil 1 (synthetic) finds new and wonderful orifices to leak out of due to it's abilities to penetrate fine cracks. (but that's another story)

dwak
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2x924NA's for parts
931
924S

[Khal]

[OutOfTheBox]

Synthetics are good for turbo's, because they dont suffer from carbonisation anything like a standard organic oil.

The problem isn't so much the metal temps, as the engine is now off, so temps even though very high, can only go down.

The problem is, the oil is no longer flowing through your turbo bearing shaft, so the oil that is stationary there, heats up to to the casing temp of your turbo, and if its normal organic oil, it carbonises the shaft.

This build up of carbon on your shaft, causes premature turbo failure.

You will increase your turbo lifetime , by always having clean oil, because of this.

As soon as I see my oil blacken in the slightest, I change it out

[Devam]

Hello Aussie 931,

Are you a female Porsche 931 owner?

It wouldn't hurt to let it idle, maybe you could fit a turbo timer if it is inconvenient, I am thinking of getting one. How long to set it for do you think?

[Paul]

I always keep my foot out of the throttle as I drive the last 1/2 mile through my neighborhood and then let it idle about a minute once I park it.
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White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[Aussie931]

Yes, I am a female 931 owner. If there are any other female owners it would be great to get in touch. You can see my pic in the latest edition of people magazine (Australian mag).
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1979 Series 1 924 turbo

[Khal]

[Aussie931]

Sorry to disappoint, but it seems as though someone has been mucking around with my computer while I was logged on - good reason to log out when you leave the room .
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1979 Series 1 924 turbo

[Khal]

Good one!
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'80 924 Turbo