cool down

[Rwill]

i was reading on another thread(trying to search 0-60 times) that you should let your diesel cool down.. can someone elaborate on this please.. i usually just shut my truck off when i pull in the driveway no matter how far ive driven it or how got its gotten.

[amdriven2liv]

For me, it depends on how I have been driving. Around town, I just idle along in parking lots and what have you. I use that to cool down.

When I'm coming home, I let the truck cool down as I drive through the neighborhood.

When towing and working hard, I'll let her cool 2-3 minutes before shut down. Sometimes on Hot days, (when pulling my Travel Trailer) I will pop the hood and check things out to help it cool down.

[nccatfan]

I'll usually sit in my truck and listen to one song before I shut mine down. Mostly just don't want the turbo spooled up when you turn the key off... turbo keeps spinning, but there's no oil flow!

[Ironmover]

S**t yeah you should cool it down. Under most normal driving conditions it can take 3 minutes or so for the egts to come down to 300* or so. Don't know what most other PSD guys find acceptable but I definately let her rest before shut down, you damn sure don't want to kill it right after rompin hard on it. As amdriven2liv lived said I agree that just easin thru the neighborhood or parkin lot is usually pretty good and then I'll still wait a few moments before turnin it off. Im never in that big of a hurry to go in somewhere. lol

[amdriven2liv]

The following is from BD Power Turbo cool down timer:

""A typical turbocharger can spin in excess of 100,000rpm under load, which will continue spinning when the engine is turned off.""

""The turbocharger is lubricated and cooled by the engine oil, and when the engine is turned off, that oil supply is cut off. If a turbocharger is still spinning at a high RPM when the oil supply is cut off, the internal bearings will utilize what remaining oil is around them then start to heat up - essentially cooking the oil, which causes premature bearing failure. By allowing the turbocharger to slow down to a safe RPM, this bearing failure can be prevented.""

""A very efficient means of gauging a safe time to turn the engine off is by the exhaust temperature. The suggested temperature range to go by is below 400°F (with the thermocouple mounted post-turbo). The further away the probe is away from the turbocharger, the lower the shut-off temperature should be. If the thermocouple is mounted pre-turbo, then the shut-off temperature can be higher.""

[Ironmover]

Hey Sean, off hand you know of how far down on the DP a pyro probe is usually mounted? Is it more of a preferance or have people found an optimal posistion?

[amdriven2liv]

Moyockpowerstroke and others have posted pictures of this probe install. Moyock has been doing a fantastic job of photo documentation of different things. Here is the link to his probe install pre turbo.

Ford Truck Enthusiasts Forums - MoyockPowerstroke's Album: EGT Probe installation

[HeavyAssault]

I have found that waiting more than 3 minutes is quite often long enough. Watching my EGT gauge I'll hit 375*F or cooler then shut her down. I got 129k on the original turbo and injectors using synthetics across the majority of those miles with ZERO issues.

Suggestion: Get an EGT gauge and watch it for yourself. Find what temps you feel are reasonable and shut her down. I think this mentality is from gasser turbos which run over 1000*F at idle!

[mudrunninpig]

I have a turbo timer on my rig. I can set it from 1-120 minuites and can pull the key and lock the doors. the truck will say running during the cool down time then the truck will shut off. depending on what Im doing, 1-3 minuites is enough time. I just dont like sitting in the truck while the egt's drop.

[mustangman02232]

400* (post turbo) is where i wait for mine to get to