COKING & Turbo

[BIG JOE]

Coking occurs when the turbo has shut down hot. Oil cooks between the shaft and the bearing and in extreme cases builds up inside the bearing housing.

My thoughts exactly Antonio.

I try to be nice to my Turbo. If, after a sustained Pull or Run.. EGTs are 400* or more ? I idle it 'till it cools to 250/300*, or less.. before shut down.

What a Turbo Saver is all about ? And partly why most "Big Trucks" idle at Rest & Truck Stops....? Letting things Cool Down.

 

[550roofer]

so is cool down still important? u know, with all the advancements in oil and everything i heard it is not a concern, i find that hard to believe, probably boils down to preference.

 

[platinum01]

My thoughts exactly Antonio.

I try to be nice to my Turbo. If, after a sustained Pull or Run.. EGTs are 400* or more ? I idle it 'till it cools to 250/300*, or less.. before shut down.

What a Turbo Saver is all about ? And partly why most "Big Trucks" idle at Rest & Truck Stops....? Letting things Cool Down.

I am the same way. If I am running around town I don't really worry about a cool down. I don't just shut the truck off but I don't idle for ever. Now when I am running in from out of town or a long trip i'll pull in the drive way and just let the truck idle for 10+ mins just to cool down. Don't know if it helps or works but my personal preference.

 

[bushpilot]

cool down is still important, not as much as it was "in the old days"
the oil circulation (around the bearings/shaft) is better...after a
hard <high heat run> you should let things idle & cool down.

an egt gauge is good for this.

the problem with shutting down after a hot run is that
the oil no longer circulates around the turbine bearings &
shaft....any remaining oil/film can cook onto the bearings.

i think some are confusing COKING (of oil) around the bearings
and SOOT BUILD UP around the vanes on the exhaust (turbine)
side of the turbo.

some of the "issue" is that some have taken cool down to the
extreme....idling TOO long (w/ an EGR & VGT based system) can
cause soot build up.

 

[85buggy]

Levels

Air filter still stock coolant levels good

 

[BIG JOE]

so is cool down still important? u know, with all the advancements in oil and everything i heard it is not a concern, i find that hard to believe, probably boils down to preference.

I think it is. But yer right.. Probably boils down to Preference ??

Joe

 

[85buggy]

extended running

There has been more answers then I thought about when I brought the Turbo subject up. Now I need to ask about extended idling .Lets say I take a break on the highway and let the truck idle for 30-40 min while I rest is this bad also does it build up soot ect...

 

[bushpilot]

There has been more answers then I thought about when I brought the Turbo subject up. Now I need to ask about extended idling .Lets say I take a break on the highway and let the truck idle for 30-40 min while I rest is this bad also does it build up soot ect...

even if you need the heat or a/c id say its wasteful and unnecessary,
not to mention potentially dangerous (fumes and "keys" issues).

certainly if your tired thats dangerous TOO...no doubt.

i cant imagine there being a TRUE need for idling that long, some will
say batteries/lights issues, construction work but i even wonder about that.

 

[BIG JOE]

Ever wunder why, at the top of a Long Hard Grade.. there's a Turn Out.. full'a trucks ? With their engine running ? Some with their Hoods/Cabs up ?

It's not only for a Brake Check, before going down the other side. it's a place to let things like.. Turbo's, Oils, Coolants, Tranny's and Rear-Ends.. Cool Down Some. Even some Drivers need a Cool Down... cuz they turned off the A/C (I did ) to have Max Power to pull the Long Hard Grade. Letting things Cool Down some.. It's purdy good idea.. for an Engine who's primary Operating Principle is HEAT.

Go'n ta Supa Bow.... Later

 

[roosterdiesel]

so is cool down still important?

Yes it's still important. My owner's manual states it. Only after long pulls when the turbo's hot and sweaty is when I really worry about it.