rangerst

Iv'e been hearing a little consern about cooling down the turbo before turning off the motor. My exhaust gas temp, pre turbo normally runs 7-750 crusin and around 850 degrees on some hill climbing and usually backs down quick to 4-450 at idol and if I take my time ejecting, 2 minutes, the temp hits 300 before my feet are on the grouind.

what's recomended and why?
anybody had any problems?

thanks, STY

BigBlue

300 pre turbo is just fine.

dodgediesel4x4

The reason we let it cool down is because the oil that lubes the turbo is perty darn hot and by shutting off the oil supply to cool the turbo, you may burn out the bearings. This is a brief explaination. I'm sure some more can chime in on this.

BigBlue

The oil will actually start to solidify (or coke) on the bearings and it will mess stuff up in a hurry. This is how it was explained to me. On the other hand, I usually shut mine off at about 450* pre turbo and have been doing so for the past 56,600 miles and my turbo spins very easily still and is still as tight as the day I got it.

jrs_dodge_diesel

Click here. This will give you a better idea on how everything works.

rangerst

good stuff,all!

Are synthetic oil flash pt higher or lower than dyno? Better for turbo's? Also thinking just for R&D if I recorded the turbo housing external temp. would that reading be indicative of bearing temperature as well, yet less than the egt at shut down?

Any problems with low flow or pressure when oiling at idol [low rpm] with the ctd?

STY

jrs_dodge_diesel

I believe synthetics have a higher flash point, but I am not sure. I wouldn't bother with recording temperatures. Bearing temperatures should be the same temperature as the oil, since the oil is its prime cooling. Don't worry, plenty of oil flows during idle. I personally get 40 psi at idle.