Hey guys,
I've been letting my EGTs drop to at least 350 before shuting down. I believe this is a safe temp. But I'm curious, at what temp do you guys let your EGTs get to before shutdown? Also, my sensor is after the turbo.

 

400 pre turbo for me

 

350-400deg for me.

 

i like to see 300 or lower... since i put the BTM on it doesn't take long at all to get it below 300...

 

350 here as well.

 

I ALWAYS wait till EGT drops below 300 ( usually 250 - 275 ) on the Western Deisel EGT gauge. It only takes 1 - 3 minutes, even after a hard hiway run ( no load ). After pulling my 30 ft 5th wheel, cooldown may take 5 - 10 minutes.

Lets the trans temp come down too.


2002 F250 Lariet Crew cab, long bed 7.3 PSD ( no mods ) automatic

 

ive got my shutdown set at 350 too

 

300 on mine but my probe is pre turbo I was told 300 pre and 350 post turbo.

 

350 post Turbo.

 

good point ... my tranny temps drop right off to since i added the tru-cool... nice to see those numbers come down also once you stop... i feel better shutting her down KNOWING that she's cooled off after a heavy tow... glad i have REAL gauges installed...!

 

anything below 400 (380ish) pre turbo and 200 before takeoff

 

300-350 pre turbo for me. I've actually read an article by gale banks stating that you don't even need to let it cool down. Read it over on ford-trucks.com, it was posted in a thread on a topic similar to this. But it never hurts to play it safe and let it cool.

 

Okay, here is how it has been explained to me by a mech engineer....

The diesel engine doesn't need to be cooled off very much, the turbo (whether gas or diesel) REALLY needs to be cooled off (and the engine will cool more than required in the time it takes the turbo to cool down). Because the turbo has engine oil in it, if you shut the engine down after it has been working hard, the oil left in the HOT turbo can cook and coke up. Then, the turbo bearings don't spin or get lubed properly because they are coated with coked up, partially solidified oil. Then the bearings burn up - bye, bye turbo.

I'm not sure how that correlates to EGT - especially pre-turbo EGT. I do know that the owner's manual recommends letting the engine run for about 10 minutes after hard working before shut down.

I'd really be interested in seeing some kind of study that correlates EGT to turbo temperature, and when if we can look at EGT to know for certain when it is safe to shut off.

 

running my pyro pre turbo... i can see a low egt temp... 300 or so... but when i walk back and put my hand in the exhaust it is VERY HOT... so... i would add that TIME is as important as the temp reading... especially if you are reading egts pre turbo like me... if i idle my engine for 5 mins with the egts at or below 300 then the exhaust coming out the pipe is barely warm... that's when i like to shut her down...

 

i mentioned i read the article on what gale banks wrote, i found it agian and thought i would post, talks about coking, like Arninetyes mentioned. what i read.....

Lots of advice on cooling turbo before shutting down. However, take a look at what Gale Banks has to say about this. I copied from bankspower.com, knowledge section tech articles, myths about modern turbo diesels.

================================================== ==================
[MYTH #7
You have to let a turbo-diesel idle for two minutes before you shut it off.

FACT
This is a current myth that has a basis of fact stemming from many years ago. It also has a kernel of truth regarding today’s turbocharged gasoline engines that operate at higher peak exhaust temperatures than turbo-diesels. In the early days of turbochargers, the turbo shaft was supported by a babbitt bearing that could seize, or even melt, if the engine was shut off immediately after sustained boost conditions where the turbocharger would “heat soak”. A two minute cool down at idle allowed the turbocharger to dissipate any remaining spinning inertia, and the oil circulation cooled the bearing and prevented oil “coking” in the bearing area. Turbochargers haven’t used babbitt bearings for over 30 years, and today’s oils resist coking. Synthetic oils won’t coke, period. With a turbocharged gas engine, it’s still good insurance to let the engine idle for 30 seconds to a minute to allow the turbo or turbos to dissipate any inertia and to cool the bearing area to prevent oil coking, especially if the engine has been worked hard just prior to shut-down. Of course, using quality synthetic oil eliminates this potential coking problem.

Today’s turbo-diesels are a different story. There is really no reason to “cool down” a turbo-diesel these days, but you won’t hurt anything by doing it either. You can still find people who swear you have to do it, but the myth is fading. Maybe they just like to sit and listen to the radio.]