do you live in alaska ?? that is fast ! ! !
ideally you want under 350, but 400 at the maximum.
and yes, they will get cooler the longer you idle them. i have left mine idling before for quite a while, and it has gone to like 275

but it takes a good solid 3-4 minutes to get down to 350 usually.

 

why would 400 degrees be a post turbo temp for shut down ? i understand that the post turbo takes longer if you are idling. but if you put the truck in neutral and rev the engine to a high idle, the post temps drop rapidly while the pre ones dont. i see what you are saying now even as i write this because yes, it takes a lot longer at idle for the post temps to come down and those are more indicitave of actual turbo CHRA temps.

 

I cant find anything in the manual about this subject. I maybe over looking something I duno.
If this is so crital why doesnt the truck come fractory with a pryo? If you got a few stops before an appointment like say work or something you better leave enough time to compensate for having to wait before shutdown. Just 7 stops could have to have just an hour of shutdown wait.
To be honest I dont make sure it at 400° I generally wait untell I see it drop below 600° then I shutoff. Sometimes its probally at 600° when I shutdown, guess I'm going to burn my turbo up.

 

On page 13 of the 6.0L Supplement:

STOPPING THE ENGINE
Turn the ignition to 3 (OFF). To prolong engine life (after extended high
speed or maximum GVW operation), it is recommended that a hot engine
be allowed to operate at low idle for about 7–10 minutes which would
allow sufficient time for the turbocharged engine to cool down.

 

Apparently Ford does not consider 10 minutes of idling to be excessive.


Coking (carbon) Deposits in Turbo and/or EGR Valve:
Coking deposits are usually a build up of unburned fuel or oil in the exhaust system and related components (valves, turbo, EGR valve). This can be caused by poor fuel quality, overfueling/leaking injectors, idling for excessive periods of time (especially in cold ambient temperatures), low engine operating temperatures, injection timing (calibration) or oil consumption. Unburned fuel usually appears as white smoke, but over time the coking condition can result in excessive black smoke. Coking depositis can plug the EBP sensor tube, foul the EBP sensor, cause the EGR valve to stick open, block the EGR cooler, plug the MAP (boost) sensor hose, or cause the variable turbo vanes to stick open (no power/boost) or closed (excessive backpressure, black smoke, popping noise, bucking). The cause of the coking issue should be identified before replacing parts to prevent reoccurance. If poor fuel is suspected, use Stanadyne Performance or Motorcraft PM-17-A Cetane Boost. TSB 06-4-12, 06-23-16.

 

Good information in that TSB about extended idling.

It is a trade off, idling for the sake of idling with an EGR equipped diesel is bad news, and will cause excessive coking and wet stacking. But when you have a hot engine and hot turbo, idling to cool down the turbo is much more important than worrying about idle time.

Basically the rule is to only idle if you must (ie to cool down a turbo), and if you must idle longer than ten minutes for any reason other than to cool down the turbo, you need to do the High Idle Mod. FMC specifically says that if you idle longer than 10 minutes elevated idle is a must.

 

LOL, I live in western Washington so the temps outside are around 50 degrees this time of year.

Usually when I pull up to my garage, the EGTs are sitting around 475 to 500. It really drops fast (5-10 seconds) to 400 then it takes ~20 seconds to hit 375.

 

So it is. Although its page 12 in my book. And come think of it I have read it.

Are they not talking about the engine itself needing to be cooled down? If thats the case I dont think watching the EGTs are going to indacate when it is aight to shut down.
What does FMC concider high speed or extended? Is the extended considered over time or miles? This is starting to get alittle confusing.

 

The turbo is part of the "engine" in this context.

Both. There's no specific number of miles, minutes, speed, etc. It all depends on operating environment and conditions. Any kind of driving that gets the engine hot enough to cause coking of oil, notably on the turbo shaft/bearings, is what they're talking about.

 

Aight then. Whats hot enough? There has to be some kind of numbers. I do however understand the GVW, see thats easy enough for a guideline. When you take into account that most of use here {or atleast a higher percentage} has pyros and tranny temp gauges etc, that percentage is because of the source. Most people come to this forums to get advice of modding their trucks/cars and/or get advice on fixing a problem. I'm willing to bet that there is alot more PSDs on the road without aftermarket gauges than with. So they have to have some kind of rule to go by wither they extended the high speed, but yet what is "highspeed"? 55? 65? 93% of my driving is at 55mph. I may get to 6?mph sometimes passing, leaving about 4 % under 55mph. The few seconds it takes to get to 6?mph and pass someone is that extended high speed?
The words that FMC used in this text is unclear and rather vage. Think about it. If at every stop you made you waited 7-10 minutes{FMC suggestion} just to make sure you if by chance you extended "highspeed" your going to eat up alot time and in a days time your truck in going to see alot of idle. It would have been so simple if between the yellow area and normal if Ford would have put a section for engine needing cooling down time or they define extended highspeed.

 

I agree with blackhat about a post turbo temp guage, although not very many people are going to run one, myself included. I grew up on a farm and , bear with me here, tractors are somewhat of a different beast than psd's, but tractors pull all day long at max rpm. The egt's on our tractors usually ran around 1050. These were older tractors and the materials used back in the day was not as resistant to heat and the exhausts were pretty much 4-5" straight pipes. Anyway, in 25 years of working on the farm I replaced 1 turbo (which was on a tractor we bought used and was 20 years old when we got it and had no idea of previous treatment. We always let the egt's get to 400 degrees before shutting down, usually took 3-5 minutes in the early evening. Now, like I said, tractors are somewhat different, but the principals are the same. Tractors generally get their oil changed at 100 hours on our operation. If you figure 5000 miles at 60 miles an hour that is 83 hours on the engine oil. All in all, I would say for general purposes if your egt's on your psd are at or under 400 degrees you will be safe and probably not have turbo problems due to heat. Also, the exhaust housing on almost all turbos is designed to dissipate heat outside the turbo. Yes they are still probably at 600-800 degrees on the casting but that heat even with the engine off is going to dissipate outward. Otherwise the temperature of your engine oil would be anywhere from 1000-1500 degrees as it passes through the turbo, this would turn any oil into a watery substance that would not last but one trip through the turbo. Just some real world experiance being thrown into this conversation. I love my truck very much and I do not want to be the reason it goes kablooey, therefore just in my opinion 400 or less is a good round number to set your sights for, obviously 350 is a better number, but 400 I feel works.

 

I agree 100% with blackhat on this. I run both gauges and the TTM from Isspro. But I would also like to point out that you don't have to run a post turbo gauge with the TTM, all that it requires is a thermocouple mounted post turbo. It is pre-set for 300 degrees and is adjustable which is the only reason to tie into the same thermocouple with a gauge. A person not wanting to add other gauge could disconnect their existing pre turbo guage and use it with the post turbo thermocouple to set their shutdown temp and then switch back. The TTM doesn't have one included but a override switch is nice to add so when you pull into a drivethrough you can order with yelling over engine noise.

 

they are mostly talking about the turbo itself in this context,

and they mean if you have been running on the freeway, then that is high speed, if you have been towing heavy also, the best thing is to get a pyro then you know. i am usually around 600=800 degrees when i pull into my driveway, and it takes several minutes to get the temp down under 400..

remember most oil burns at well under 600* so that is not nearly cool enough for a shut down.

 

keep in mind that this was considering a truck with FACTORY programming, which runs with a MUCH lower average EGT than a modded truck, so the wait time is not nearly as high for a stock truck. the majority of trucks on the road without the gauges which you refer to, are the same trucks that are running stock ecm programs, so they dont see the kind of heat we do.

 

I'm sure glad I'm still stock. With all this crazy stuff sometimes I just want to park it and forget about it, but then that would just cause another problem "LOTROT" danged if I do, danged if I dont.