JdC Machine
Veteran Member
Don't go scaring people now. I've seen plenty of Cummins engines run above and beyond 1300degs. but those temps aren't SUSTAINED for much longer than 10-15 seconds. Watch some drag races and sled pulls. Talk to the drivers. They'll give you an estimate of what the EGTs were during the run down the track but they couldn't tell you exactly what they were because they don't even look at the EGT gauge.Doubt that running it hard on cold oil would harm it as these engines have 5W oil in them, plus historically diesels often have been run hard right after startup ( emergency backup engines and such ) without issues; what has historically taken out turbos is EGT temperatures over 1200F for any reason- these are monster numbers and I have personally rebuilt 2 Dodge Cummins iron head ISB engines that ate pistons due to being run at 1300F and shutting down one with EGT's above 1,000 is totally unthinkable.
I talked to the guy who built my Ball barring turbo on my Dodge truck- he said that all new diesels see these monster EGT's and that the new turbo's are indeed designed better.... then he said not that much better and that he wouldn't ever let one "cook its seals hard" with the engine off on a interrupted regen on any make or model.
my 0.2
Even Cummins specs that 1250degs. is a safe temperature at 100% load (for the ISB5.9's that I know of) and can be sustained safely for days on end if they need to. But that refers to keeping the pistons from melting. What generally kills turbos is not allowing EGTs to come down to safe levels before shutdown. Therefore, any oil that remains in the bearings and on the shaft will coke/burn to them. That equates to poor lubrication and cooling in the future which only becomes worse and worse every time. The magic number I learned during my diesel tech. schooling was around 400degs. F and above is chancing the oil coking on the bearings and shaft.
What I think of when I hear turbo failure during higher EGTs (at least those that are not sustained for long periods), is overspeeding of the turbo with the engine being run hard. High EGTs sustained for long periods usually only effects the pistons, turning them into liquid. The turbo(s) live. They're lifespans are shorter but they live. That is, if EGTs were allowed to cool off before shutting the engine down.
Emg. stand-by generators have jacket water heaters. The idea behind that is to keep the coolant and oil warm enough so that they can safely jump to 100% load immediately after start-up without the worry of headgasket failure. I wouldn't trust my Cummins to last very long if I were WOT throttle from start-up. I drive it (and my TDI) for about 10 minutes, allowing oil and coolant temps. to warm up before I begin to put the hammer down.
Just my 2 cents. Not attacking anybody.
In short, no. False. Unless this is new emissions technology on the LML's, Isuzu (Mfg. of the Duramax) never put a 9th fuel injector after the turbo. During a regen cycle, the only thing that has changed is the addition of a fuel injection event, generally. There's not an immediate risk to the turbo if the engine is shutdown during a regen. Only a large decrease to the turbo's lifespan. This goes for any diesel engine with a DPF that requires regeneration.Sorry to highjack the thread, but I've got a question about the diesel truck turbos. I thought that GMs method of DPF regen that uses a 9th injector after the turbo avoided the high EGTs to the turbo itself. Meaning a GM truck can be shutdown during a regen with no risk to the turbo. True?
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