Community Forums

John & Sheri · 07-05-2004, 04:10 PM

I am really puzzled over the cool down period for Diesels.. The Question is, When Traveling with your Diesel, and you pull over for Fuel, rest, or to stop and eat at a Resturant, What do you do??

John & Sheri · 07-05-2004, 04:10 PM

I am really puzzled over the cool down period for Diesels.. The Question is, When Traveling with your Diesel, and you pull over for Fuel, rest, or to stop and eat at a Resturant, What do you do??

Dave · 07-05-2004, 04:22 PM

If I'm running empty I just shut it down. If I'm pulling the RV I let it Idle for 2 minutes or so. With a diesel it is no problem to fule while idling. It's worked for me, 103,000 miles on my 01 duramax.

Jack Wilkinson · 07-05-2004, 05:18 PM

I went to a diesel seminar last year and was told that the cool down period was ~3 minutes. Dave is right on about fueling with the engine ideling- diesel is only 40 octaine and you would have a hard time igniting it from a spark. I've never seen a trucker shut down while fueling and they do it for a living. keep the enging hot!

CyberVet65 · 07-05-2004, 07:11 PM

The reason for cool down is the turbo being up around 500 to 600 degrees when coming in off the road at 65 mph. The bearings in the turbo are cooled by oil pressure lubricating those bearings. When the engine is turned off and the turbo is at 500 degrees the oil that is in those bearing will "coke up" or burn off or cook into a solid and causing premature failure of the turbo.
I have used a unit that runs the truck until the exhaust temp reaches 300 degrees then shuts off the engine. It is made by ISS Pro and has worked fine for the last four years.
Chet

Dave Fernandez · 07-05-2004, 07:28 PM

Hello:

I was told that the cool down time was necessary if you were on a hard pull where your turbo was working hard. The cool down is for the turbo so the oil is not cooked in the turbo when the engine is shut down. I was told that if you were just running down the highway without the engine and turbo working hard no cool down was necessary. I was also told the cool down time included the time when you first pulled off the highway, waiting at the light, drive into the station, etc.

Dave

FiverBob · 07-06-2004, 02:35 PM

If you are towing, you owe it to yourself to equip your truck with a EGT gauge. Easy to install and you will know not only when to shut down, but also when to back off pulling up a long grade with a load. I would not tow with a diesel without one.
Bob

FatDog · 07-06-2004, 03:05 PM

What FiverBob just said.

Dave F., install that EGT gauge. You will really be surprised. I live at the end of a long, dusty lane, flat and slow, and I drive my truck like someones grandma. My driveway at the end of the lane is curved and a bit steep. By the time I get to the top of the driveway, the EGT is 500 whereas it was 400 at the bottom. I'm probably driving it at 15 mph. That last few hundred feet requires an EXTRA minute to cool down. My next door neighbor on the hill has a similar driveway but has never installed guages in HIS Powerstroke. He is convinced that since he also drives so slow, that he can idle it for a few seconds and then turn it off. I know he is turning his turbo off at 400+ degrees. I wince with pain.

gauge = $80

vaughn · 07-06-2004, 03:40 PM

I have an '01 Dodge and I have an exhaust gas temp.guage installed just after the Turbo. Even when I am running fairly easy (60 MPH or less) on level roads, it still takes 1 - 2 minutes to see the temp. get down to 350 degrees. When I pull off the road, such as into a shopping center parking lot and get parked, the EGT is typically about 400 degrees. If I wait till it gets down toi 300, its at least 2-3 min. If I am running up hill with the fiver on, it is at least 4 min to cool to 350.

Vaughn

John & Sheri · 07-06-2004, 05:06 PM

Hmmmm

Than the best route is to buy a EGT Gauge.. Time to search the web

John & Sheri · 07-06-2004, 05:15 PM

Ok.. now im really Confused... whats the difference between a EGT and a Pyrometer?? Which is better to use??? and how hard is it to install one????

Ken Lenger · 07-06-2004, 06:33 PM

EGT = Exhaust Gas Temperature, and is the same as a pyrometer. It can be mounted before the turbo to provide a good indication of internal cylinder temps, or post turbo to provide a good indication of turbo temps (for cool-down purposes).

Skytx · 07-07-2004, 03:04 AM

Ken,
How involved is it to install a pyrometer? I have a 2003 6.0 L Ford. Is there alread a tap for the temp probe or does it have to be drilled and tapped? We have them at work on each cylinder of the 1500 hp V16 compressor engines, but the exhaust manifold is already tapped for it. I have never really worried about cool down unless I was pullling a trailer, but the only way to know is to have a gauge.

Dan

Ken Lenger · 07-07-2004, 04:18 AM

Skytx:

I'll have to defer your questions to other members. I am not familiar with Ford, and don't have gauges installed on my truck. I'm waiting for BrakeSmart to offer the boost/EGT option to their brake controller before I do anything. The exhaust brake houseing on my truck is tapped for an EGT probe, but that would be a post turbo installation. For pre turbo, I'd have to drill and tap the exhaust manafold, but understand it's pretty easy to do.