RowJ

Don't ever remember seeing this topic being discussed...did 2 searches and found nothing.

With cooler weather, I am expiriencing longer than normal time to get EGT's below 300*. Only change in last 3 months has been addition of FASS, but actually thought that pump was speeding things up...until cooler weather hit. Seems as though EGT's should cool faster in colder temps? Can't remember seeing this phemomenon last winter? Anyone else have similar results?

RJ

Haulin_in_Dixie

Mine seems to do that too. No idea as to why. I just wait it out.

BigBlue

I just shut the truck off.

infidel

If you are cooling down with the heater in the defrost mode the A/C is also on and will prolong cool down because very hot air flows though the intercooler from the A/C coil.

RowJ

Sorry, forgot to mention it...comparing apples to apples...all blower systems off.

RJ

RowJ

Found a leak in my FASS install. Intake fuel line vibrated loose. Fuel getting out...maybe air getting in? Apparently just coincidence that it happened as the weather here turned cooler.
Was acting just like the heater/defroster was on...last 25* to get under 300* was taking an extra 60 sec. Cool down appears back to normal, now.

RJ

Eskimo

Not to sound like a smart-alec, but um... when the turbo sees 1000* easy, what's a 25* difference?

RowJ

I agree with you...especially since I'm using synthetic oil. On the other hand, it's the only $35,000 truck, with a $1,600 turbo on it, that I have. Cooling the heat around the oil in the turbo to 100* below it's flash point seems, to me, like reasonable preventative maintenance.
AND, maybe an argument can be made for less harm from flowing oil exposed briefly to 1000* versus sitting oil baking at 325*?
My original concern around slower cooling down was about a new and unexplainable change in the way my truck was acting (in cooler weather)...not so much the actual temp. It caused me to look for a cause...and find a fuel leak!

RJ

Geico266

More than likely there are two causes of higher EGT's.
1. Caused by cooler (denser) air. The cooler the air, the more "thick" it is. This means more air is getting into the clyinders, for better performance. This is also why they added the inner cooler. I see this in airplane engines all the time.

2. Winter blended fuel. Its the opposite of what you think would happen. The same with gas engines. The lower the octaine the higher the EGT's.

Nothing to worry about or adust to.

If you are really pushing the CDT hard then I'd let it cool off for a while so the oil does not "choke" in the turbo. If not shut her down and it's Miller time. Someone else can chime in on the temps, but I think around 300-500 degrees you are okay.