Turbocharged vehicles and start/stop systems.

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Nov 7, 2012
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Louisville, KY
Back in the 90's I had a 300zx twin turbo. A popular upgrade at the time was a "turbo timer", it would keep the engine running for a while after you turned off the key to let oil circulate and cool so the turbo bearings would last longer. Nowadays turbocharged vehicles are common and so are start/stop systems. I was wondering what changed to make the turbos long-lasting with the engine constantly turning off: Oil Quality? Oiling systems? Nothing?
 
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Sep 17, 2012
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I have two elderly turbo charged vehicles, a Saab and a Volvo. I generally let them idle about 10 seconds before shut down especially on a hot day after a higher speed run. They are both water cooled units running on synthetic oil so never had any issues with either. Some things naturally tend to stay in motion awhile although they are not engaged like a barber's scissors even when away from your hair or a track runner or horse after crossing the finish line.
 
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Aug 28, 2012
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NC
Good question and IMBHO the start/stop system is the most idiotic thing still being implemented. I want a vehicle that is ready to respond when I expect/need it to and don't like to wait even a nanosecond for that to happen!
 
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Turbo timers were nothing more than a placebo to get people to spend money on an aftermarket upgrade.

Modern turbos and even early ones used natural convection designed in turbo cooling especially with mechanical water pumps to keep coolant moving once engine was shut down. I do know my wife's VW Tiguan tends to whirr and I am guessing electric coolant pump running after shutdown and during start/stop.

Turbo's seem to last a long time , my wife managed 240k / 13 years on a 2005 Subaru Legacy wagon before sold and we used Dino oil every 4k miles.
 
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Back in the 90's I had a 300zx twin turbo. A popular upgrade at the time was a "turbo timer", it would keep the engine running for a while after you turned off the key to let oil circulate and cool so the turbo bearings would last longer. Nowadays turbocharged vehicles are common and so are start/stop systems. I was wondering what changed to make the turbos long-lasting with the engine constantly turning off: Oil Quality? Oiling systems? Nothing?
My Mercedes has a turbo V8 and the coolant circulates long after the engine is shut off to cool down the components including the turbos.
 
Joined
Apr 18, 2005
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Easton, PA
Turbo timers were nothing more than a placebo to get people to spend money on an aftermarket upgrade.

Modern turbos and even early ones used natural convection designed in turbo cooling especially with mechanical water pumps to keep coolant moving once engine was shut down. I do know my wife's VW Tiguan tends to whirr and I am guessing electric coolant pump running after shutdown and during start/stop.

Turbo's seem to last a long time , my wife managed 240k / 13 years on a 2005 Subaru Legacy wagon before sold and we used Dino oil every 4k miles.
They do have an after-run electric pump for the turbo but I am not sure if that is on with the S/S system. I do know the transmission has an electric pump to keep pressure to the clutch packs so you can just go from a engine off stop.
 
Joined
May 7, 2020
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Ames, IA
I was told on this very forum I was WRONG when I suggested this was an issue. Oh well. Thankfully I knew I wasn’t wrong, so I still felt good about myself.

Dad taught me to always idle a turbo engine for 30 seconds or so. I still had one go bad in my F150. It was not a start stop truck, being a 2016.
 
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