[stevehecht]

Someone brought this up in a thread the other day and I had never heard of them. I know what they do, but how complicated is it to set one up? How expensive? Are certain manufacturers preferred over others? Is the turbo timer needed for average rpm runs or just when you've run the car at high rpm for a while? I'm the kind of guy who will either just be too impatient to let the engine cool down, or will just forget. I'm particularly interested in their usage with diesel engines since I have a 328d.

[Fille]

I know they're utterly useless...
Just idle it yourself for one minute OR drive calmly before you stop.
Don't go full retard and install one just because you're a bit lazy and don't want to sit and wait

[stevehecht]

Originally Posted by Fille

I know they're utterly useless...
Just idle it yourself for one minute OR drive calmly before you stop.
Don't go full retard and install one just because you're a bit lazy and don't want to sit and wait

OK, I like it!--especially the "full retard" part.

[AweSam8]

I'm pretty sure cars nowadays done need it...

[snowghost]

Originally Posted by AweSam8

I'm pretty sure cars nowadays done need it...

+1

[RPM90]

Originally Posted by stevehecht

Someone brought this up in a thread the other day and I had never heard of them. I know what they do, but how complicated is it to set one up? How expensive? Are certain manufacturers preferred over others? Is the turbo timer needed for average rpm runs or just when you've run the car at high rpm for a while? I'm the kind of guy who will either just be too impatient to let the engine cool down, or will just forget. I'm particularly interested in their usage with diesel engines since I have a 328d.

If you have a BMW turbo, then you don't need one.
Systems are in place to make sure your hot turbo doesn't continue to cook once you shut the engine off.

[Blubaron79]

^ yes. The water pump will run and cool the turbo(s) after you park.

[floydarogers]

Originally Posted by RPM90

If you have a BMW turbo, then you don't need one.
Systems are in place to make sure your hot turbo doesn't continue to cook once you shut the engine off.

Originally Posted by Blubaron79

^ yes. The water pump will run and cool the turbo(s) after you park.

But not on the diesels... which the OP has. The N47 (and the older M57) have belt-driven waterpumps, so coolant won't be circulated...

[stevehecht]

Originally Posted by floydarogers

But not on the diesels... which the OP has. The N47 (and the older M57) have belt-driven waterpumps, so coolant won't be circulated...

Thanks, Floyd. You're definitely one of the sharper blades around these parts.

Now let me ask you (& others): How hard would you have to run the engine in order to risk some damage without appropriate cool down? This is a ballpark estimate of course.

[floydarogers]

Originally Posted by stevehecht

...Now let me ask you (& others): How hard would you have to run the engine in order to risk some damage without appropriate cool down? This is a ballpark estimate of course.

I've never really worried about it; but then I have a 2 mile 30 mph drive to get to my house. I'd say a couple minutes should be sufficient to circulate enough oil and water to get them cooled down?

[stevehecht]

Originally Posted by floydarogers

I've never really worried about it; but then I have a 2 mile 30 mph drive to get to my house. I'd say a couple minutes should be sufficient to circulate enough oil and water to get them cooled down?

I'm not sure you understood my question. I was asking about how hard & long would you have to run the engine so as to risk some damage WITHOUT a cool down period when stopped?

[floydarogers]

Originally Posted by stevehecht

I'm not sure you understood my question. I was asking about how hard & long would you have to run the engine so as to risk some damage WITHOUT a cool down period when stopped?

It would have to be some scenario involving a full-throttle climb up a pass, say to Sunrise or Paradise at Mt. Rainier. Or towing a trailer up there at a more moderate pace.

These engines are overkill and don't even warm up all the way unless you're climbing a hill. Search around for TDIwyse's thread where he was talking about cold-weather warmups and posted a coolant temperature graph for his commute - a couple years ago now. He's also posted a recent graph of exhaust temps that show rises when he's doing ET kinds of things, and mentions not seeing them rise otherwise.

[NISFAN]

Originally Posted by stevehecht

I'm not sure you understood my question. I was asking about how hard & long would you have to run the engine so as to risk some damage WITHOUT a cool down period when stopped?

Turbo timers were helpful back when Turbo chargers were only cooled by air and the lubricant (engine oil).

Almost all modern turbo's have a water jacket to cool them. It isn't when they are running that it is critical, more an issue with the turbine side potentially being at around 2000DegF when stopped, causing oil to coke on the turbine shaft, due to it heating up under heat soak. This coking then eats into the (old style, many now have ball bearings) journal bearings, causing premature wear.

In your case, the problem is far less of an issue in the case of a diesel. Diesel EGT is significantly cooler than petrol, typically around 1400F instead of 2000F. Also, when idling a Diesel EGT is lower too, adding to the cooling effect. Google images of a petrol turbo system glowing red hot, this can happen on even stock street cars. It is not likely to happen on anything other than highly tuned diesel engines.

This plus the water jacket which adds mass to dissipate the heat in the turbine, plus fully synthetic oils, plus better bearings, all lead to much more 'tolerant' turbo system.

As long as you run the engine off boost for say 20-30 seconds (parking up), the turbo will have cooled to well below the threshold that causes the oil coking issue.

This is what a Petrol engine has to put up with, and the reason why a TT is a good idea, if you drive it hard without cooling.

[stevehecht]

Originally Posted by NISFAN

Turbo timers were helpful back when Turbo chargers were only cooled by air and the lubricant (engine oil).

Almost all modern turbo's have a water jacket to cool them. It isn't when they are running that it is critical, more an issue with the turbine side potentially being at around 2000DegF when stopped, causing oil to coke on the turbine shaft, due to it heating up under heat soak. This coking then eats into the (old style, many now have ball bearings) journal bearings, causing premature wear.

In your case, the problem is far less of an issue in the case of a diesel. Diesel EGT is significantly cooler than petrol, typically around 1400F instead of 2000F. Also, when idling a Diesel EGT is lower too, adding to the cooling effect. Google images of a petrol turbo system glowing red hot, this can happen on even stock street cars. It is not likely to happen on anything other than highly tuned diesel engines.

This plus the water jacket which adds mass to dissipate the heat in the turbine, plus fully synthetic oils, plus better bearings, all lead to much more 'tolerant' turbo system.

As long as you run the engine off boost for say 20-30 seconds (parking up), the turbo will have cooled to well below the threshold that causes the oil coking issue.

This is what a Petrol engine has to put up with, and the reason why a TT is a good idea, if you drive it hard without cooling.

I guess that settles that! Great information, thanks. Cool turbo photo, too. Er... I meant hot turbo photo....