GLA Turbo cool down time

[schwartz11]

Hello all, and thank you in advance for your thoughts. To my understanding, turbo lifetime is improved by a post-use cool down period. This is substantiated by auto-start and security systems with a turbo cool-down timer feature. Have the AMG engineers devised some cooling system for the GLA 45 turbocharged 4-cylinder that continues to provide coolant after the engine is shut off? The fact that the default (at least in the US) is for the engine to cut-off when at a full stop with the brake applied, makes me ‘hope’ they have engineered a solution for the turbo cool down.

 

[RJ C63]

You would hope they have!!

 

[Mr Kripling]

Could someone explain to me why providing coolant after the engine is shut down would make any difference? Once the engine stops running the turbo isn't going to get any hotter than its operating temperature...

Also, I understood that turbos were cooled by the engine oil - I can't imagine that the oil pump is going to be operated electrically post-shutdown.

 

[stwat]

Could someone explain to me why providing coolant after the engine is shut down would make any difference? Once the engine stops running the turbo isn't going to get any hotter than its operating temperature...

Also, I understood that turbos were cooled by the engine oil - I can't imagine that the oil pump is going to be operated electrically post-shutdown.

It's to prevent heat soak cooking the oil that's left in the bearings of the turbo/compressor. My 944 turbo had an electric water pump that would keep running after you switched the engine off. It would run until the turbo had cooled down to a certain temp.

 

[moonloops]

Could someone explain to me why providing coolant after the engine is shut down would make any difference? Once the engine stops running the turbo isn't going to get any hotter than its operating temperature...

Also, I understood that turbos were cooled by the engine oil - I can't imagine that the oil pump is going to be operated electrically post-shutdown.

Residual heat build up used to cook turbos - engine off, no oil flow due to mechanical oil pumps. It's not been a problem for modern engines for at least 15 to 20 years now. Nowadays yes coolant pumps are electric and water based coolant is used.

Anyone with a turbo engine just needs to be off boost for the last few mins of their drive and turn the motor off as normal.

If you are still paranoid about it all, you can always buy a bus ticket

 

[MWCLS]

Residual heat build up used to cook turbos - engine off, no oil flow due to mechanical oil pumps. It's not been a problem for modern engines for at least 15 to 20 years now. Nowadays yes coolant pumps are electric and water based coolant is used.

Anyone with a turbo engine just needs to be off boost for the last few mins of their drive and turn the motor off as normal.

If you are still paranoid about it all, you can always buy a bus ticket

Or a turbo timer .

 

[moonloops]

Or a turbo timer .

A waste of money when compared with the ability to lift your right foot for a minute or so

 

[pete harrison]

Anyone with a turbo engine just needs to be off boost for the last few mins of their drive and turn the motor off as normal.

I have owned several turbo powered cars (both petrol and diesel) since 1994, and done high mileages with most. I have always used good quality lubricating Oil and then as 'moonloops' has said drive the last mile or so sensibly to allow the Turbo to loose some of its heat. I have never sat and waited for the Turbo to cool with the engine ticking over or used a Turbo Timer, and I have never replaced a Turbo yet.

edit = My observation over the years is that poor maintenance or increasing boost pressure are the principal Turbo killers.