Engine Cooldown

[DFDureiko]

this is my first turbodiesel tow vehicle. it's a nice '01 Sierra Duramax extended cab shortbed with 47,000 on it. Currently we tow a 7100lb Airstream, but plan on getting a newer heaver one in the next year or two, about 9800lbs.
One thing I"ve read about is cooling down the turbo after spending hours hauling. Can anyone recoomend a good cooldown timer?
Should I get one based on time, or one that would shut down once the EGT reaches a certain number?
I"d like to obtain this and get it installed before the end of the summer, as I usually bring the rig to FL for the winter.

Dan
2001 GMC Sierra HD Duramax 2wd
1977 Airstream Sovreign 31ft
Hensley Arrow Hitch

[DmaxMaverick]

I don't think cooldown timers are necessary for our trucks. The turbo is liquid cooled, and is designed very well. I have an EGT gauge, and watch it closely. Even after climing a 7% grade for several minutes, the temp will get below 300

[Heartbeat Hauler]

[QUOTE=DmaxMaverick]I don't think cooldown timers are necessary for our trucks. The turbo is liquid cooled, and is designed very well. I have an EGT gauge, and watch it closely. Even after climing a 7% grade for several minutes, the temp will get below 300

[HowieE]

When you get your EGT guage make sure it is install Pre Turbo. There is genrealy a 200 degree drop across the turbo and if you rely on a post turbo guage you may get yourself in trouble.

Just don't be in a hurry to shut down your deisel. The guage will show air flow temperature over the sensor and not the turbo body temperature. Metal cools down a lot slower than air. It is the body temperature that will cook the oil on the turbo shaft. If I stop after a hard pull, to look over the edge at some view point, I will just let the truck run rather than shut it down

[DFDureiko]

thanks for the reply I almost ordered the BD-Xmonitor with cool down timer.
this brings up my next question. I'll be towing MAX a 34ft 10,000 Airstream, well under the tow rating, do I need a EGT/Turbo Boost and Trans Temp gauges? the truck has a trans temp factory gauge.
I just figure the simpler the better? I know some people just like having all that information, (I have a friend like that, with a early dodge and so many gauges that it looks like the flight engineers station on a L-1011)
One thing I believe I need, to avoid injector problems, is the aux fuel filter, which is better, kennedy diesel or Lubrication specialists? I'm not bothering with aux oil filiter as I plan to change the oil/filter fall and spring (I plan on putting under 10,000 miles a year, perhaps even 7 or 8,000) and I'm going to all Amsoil synthetic fluids.
Dan

[HowieE]

My comments were based on my history of the 6.5 engine. As far as to the limits of the D Max I would suggest you look on and maybe post a question on that section of the Page.

One thing to keep in mind with a diesel is the changinh of the oil is much more important than with a gaser. I would have a set schedule based on mileage rather than just spring and fall. You may take a trip that pust you over the limit if you just relay on time of year.

John Kennedy has extensive knowledge of the D Max and has always been a great source of information. You will not go wrong with dealing with John.

[Heartbeat Hauler]

I agree. And if you want to do the AMSOIL syn extended change intervals I would make sure that you are doing oil analysis to determine change times. With the AMSOIL, you could probably do a change every 7500 miles without analysis as that is a recommended interval for light duty use. I just use Rotella T 15w-40 and change every 5000miles (heavy duty use).

And as far as guages go, Egt & boost guage for sure. Most guys in the know seem to think the factory trans temp guage is purty good, but if high trans temps are a concern you might wanna consider changing to Transsynd trans fluid, or AMSOIL equivalent. This will allow you to run higher temps without the fluid breaking down.

Ditto on working with Kennedy.
JP

[winemaker]

When I get where I'm going after a long haul, I generally leave 'er running, go grab a cold beer from the cooler, and reward myself for doing such a fine job of driving. A little walk around the campsite to assess, a leisurely quaff, then shut 'er down. I think it's just because I like cold beer and the sound of diesels, but I've "educated" my wife as to the merits of this activity, so all is well......
Cheers! Brett

Remember, it's not procrastination if you put it off RIGHT NOW!

[jspringator]

I have an extra remote locker in my ashtray. When I go to a rest area, I leave the truck running and lock the doors with the remote. Mine takes a while to cool down to 300 degrees, and this is measured post turbo. I think mine is really working hard to tow my load. Unless I am going to eat lunch or something, I don't usually shut the truck off. Much easier, simpler, and cheaper than a timer. A timer is one more thing to troubleshoot when your truck won't run.

[BurnsK]

Not so sure I agree with no cool down time. General Electric, Rolls Royce and Pratt and Whitney all recommend cool down times for their turbine (jet) engines, regardless of EGT/TIT/ITT. Our turbos extract energy (in the form of heat) from the exhaust, just as a jet engine does, so the principles are generally applicable across discipline. A little cool down now will save a lot of down time later. By the way, it's two to three minutes at idle for all the manufacturers.

[Inspector]

Generally speaking with turbine engines,, 1 min at take off, 5 minutes at idle.
When taxiing in from a flight by the time you park at the gate your cool enough. You have to realize that take off power EGT can be as high as 630 degrees measured in degrees Centigrade. Ours are working in degrees Farenhiet. A considerable difference. Turbines use a much different oil for lubrication as well. Rear bearing return lube lines will coke as they are subject to high temps for extended periods of time. Take off power doesn't last more that a minute or two. You will notice that the power is pulled back to climb power shortly after take off.
Our engines run a whole lot cooler than that big ole suck and blow out there on the wing.
A good rule of thumb is to let the oil burner have a breather after a long or sustained pull near the EGT limits that you have set for your particular driving habit.
Just my two cents.
Denny

[tanker]

I allow mine engine to cool down after pulling hard. Around town to the store, work etc. I don't. I watch my EGT's, and like Howie stated let it cool down when working the engine hard. Years ago I drove some Mack trucks that had a label on the dash that said to idle engine 3 minutes before shutdown. There was not a pyrometer on these particular trucks, so that would help the engine cool and prevent turbo/cylinder head damage. Back then turbo's were fairly new in trucks, and there were no intercoolers, today things are much better in materials that will take the heat. I doubt if GM, Ford, or Cummins have anything to say about a cool down as most drivers would ignore a label telling you to let it cool down prior to shutdown. However some of us have added performance items that increases horsepower/torque, which translates into additional heat, so watching your pyrometer and temp gauge would be advisable. Just my 2 cents.