Is cooling down a TD still a thing?

[dph]

Do you still allow your turbo diesels to cool down before shutting off?

[Rainier Vermaak]

Do you still allow your turbo diesels to cool down before shutting off?

After a hard run- yes.

After town driving - no.

[mullerza]

After a hard run- yes.

After town driving - no.

Good avice for any turbo car, not just diesel

[Peter Connan]

I would love to understand exactly what the recommended practice is.

I was taught that it's safe to turn off the engine once the EGT's have reached a certain temperature (the specifics seem to vary but I use 150 degrees most of the time).

But this takes far less time than some people let their cars idle for, especially if the last few 100m are driven mildly?

[IcePick88]

If I pull into a petro port off the highway, I let it idle for a minute or two.

If I get off the highway (or get into town) and putter to my destination in traffic, I switch off as soon as I stop.

[Tiaan Pot]

I would love to understand exactly what the recommended practice is.

I was taught that it's safe to turn off the engine once the EGT's have reached a certain temperature (the specifics seem to vary but I use 150 degrees most of the time).

But this takes far less time than some people let their cars idle for, especially if the last few 100m are driven mildly?

I see the same

I have EGT gauge. Although the probes only measure the exhaust gas temps, not the turbo temp, the reading on the gauge drops very quickly - From 650 C flooring it up a hill down to 300C when you take your foot off the accelerator within a few seconds. If you drive nicely into the suburbs, it idles down to 150C very quickly. Personally, I never let it idle when I get home, turbo was still perfect after 270k km

[RoelfleRoux]

Good avice for any turbo car, not just diesel

Yet, more and more of our cars are factory fitted with ASS (including your Beast), which makes an idle-down impossible.

[mullerza]

Yet, more and more of our cars are factory fitted with ASS (including your Beast), which makes an idle-down impossible.

I have not tested it but I dont think ASS will shut down an engine that was run hard. I'm not 100% sure on the BMW but I know my ex Audi montored turbo RPM as one of its parameters.

[WernerDL]

This was so easy on the Tiguan. It had stop/start so after arriving at the destination I just let the car decide for itself when it wants to turn off.

In the Mitsu, I usually wait between 15 to 30 seconds, or if there is a nice song on the radio - till it is done

[RoelfleRoux]

I have not tested it but I dont think ASS will shut down an engine that was run hard. I'm not 100% sure on the BMW but I know my ex Audi montored turbo RPM as one of its parameters.

On our recent Cape Town road trip, I got caught arriving hot at a roadwork stop-go on the N1, with the ASS still active. My Porsche shut down immediately. I hit that ASS button very quickly to get oil pumping again. I think even Lando Norris would have considered that a very quick reaction save!
PS. I have no idea if there is a protection lubrication system on my car. One is tempted to think there may be one.
There are times when a little light on the dash shows that the stop-start isn't available, but that is either soon after start-up (but not always) or when the climate control is fighting the Lowveld heat (but not always).
But, I have never seen that little light come on when driving fast on the open road.

[_FC]

Yet, more and more of our cars are factory fitted with ASS (including your Beast), which makes an idle-down impossible.

On my wife's Cooper S start stop was disabled for a while after working the engine a bit. Suspect the same for the other BMW engines.

[Spiceman]

Always....since turbos still spin at serious rpm's.

[PieterOos]

Do you still allow your turbo diesels to cool down before shutting off?

What is your Owner's Manual saying?
E.g. for my vehicle:

[Spiceman]

Since I started driving turbo diesels I changed my driving style to accommodate the cooling down. I will always wait a minute or so. At home I have to wait for my gate to open and then I drive in and park in front of the closed garage door. Whilst opening it, the bakkie keep on idling. So when I'm inside on the right spot, its cooled off sufficiently.

[Searcher]

After a hard drive, at least a 2 min cool down sounds about right.

[jfh]

We use a 1 minute cooldown on our Pt6 turboprop engines, so I set that as my maximum cooldown.

I usually let it idle until the EGT falls below 130°C, which is about 30 seconds minimum.

[Tiaan Pot]

After a hard drive, at least a 2 min cool down sounds about right.

You might be over fuelling a tad there ...

[Searcher]

You might be over fuelling a tad there ...

Luckily not my vehicle, just a screen grab.

But my 1HD-FTE can comfortably dive at EGT's of around 600^oC -650^oC under load.
That's a deep cheery to dark red colour temperature wise.

After a stop, that going to need some decent cooling off time.

[QuQ]

Yes I still do for 2 minutes if driving over 100km/h for an extended period as that was stated in my 2009 Hilux D4D manual back then. That vehicle is long gone but that recipe has stuck, although I seem to be in the minority if I look at vehicles pulling into roadside fuel stations next to national highways. I'll keep doing it as I've never suffered a turbo failure!

[Jeepiscool]

On modern cars it circulate the oil and many times also cooling water through the turbo after you switch off. My Stelvio actually has a dedicated cooling circuit complete with own reservoir tank for it. I still prefer to idle her a bit after gunning the final stretch home, just in case. My wife's Audi TT also circulates at least the oil.