Why leave Diesel engine running for short Stops

[2013tiffin]

I am trying to find out if I should leave my Diesel engine running when I stop in a rest area, or continue to turn it off?  What is logic behind leaving it running?

[wolfe10]

2013tiffin,

Welcome to the FMCA Forum.

Short answer is to follow your engine manufacturer's advice.

Most recommend turning them OFF after a suitable cool-down period.  The cool down period can be from zero seconds (pulled into CG, registered and drove to site to 4-5 minutes in the summer if you pull into a scenic overlook after climbing a long grade in 100 degrees F temperature.

What does your Cummins manual for your engine suggest?

[bm02tj]

If for a quick potty stop  10 minutes or so let it run  

Excessive idling is not good for the motor or the environment

As Brett said read your manual  

[wildebill308]

I go buy what the EGT is once it drops below 400-450 I can shut it off. If I am stopping for lunch I will shut it off and run the generator if needed. If it is a short stop to walk the dog or me I will let it idle to keep it cool in the coach. 

Bill

[manholt]

Read your Cummins Manual.  Agree with Bill.  As for environment, I run my Generator 90% of the time that I'm not on Shore Power!  Cool coach, happy me & SO. 

[2013tiffin]

Thanks for all of our inputs.  No Cummings manual with my documents.  I'll check on line.   Engine cool down is apparently the key consideration.  Jeff  

[manholt]

Jeff.  Give a call to Tiffin Tech Dept., the should be able to send you a pdf., or call any Cummins Service Centers and they'll get you one!

[jleamont]

The flip side...How long at idle before departing in the morning? This is the one you hear the most complaints about.

I unhook, pack it all up, start the coach let it rise and build air, do a walk around the coach, hop in, buckle up and pull out, go easy on the throttle until it reaches operating temperature. 

[wildebill308]

I know Joe knows this but we don't explain it is when you start your diesel and it is cold you should watch the oil preshure and when it comes up go to "fast idle". The reason is your cold engine (below operating temp) will not burn all the fuel and it can cause problems by washing the oil off the cylinder walls and contaminating the oil. 

Bill 

[manholt]

Since I have Silverleaf and all the various probs, I have no problem in knowing when I can safely engage fast idle.  On most coaches, you turn on Cruise Control and push on set...it will bring the engine to 900/1000 +/- rpm and hold it, until you push cancel or on/off.  I do not turn Generator on, until I'm out of Park!

Now, at the next Park, let coach idle while your registering, when you get to your space...the turbo and engine should be cool enough to be shut off.  In Summer Texas, I hook up first, then turn engine off.  If your running Generator, then turn AC off before registration and turn off Generator on the way to your space or before!

[jleamont]

4 hours ago, WILDEBILL308 said:

"fast idle".

Only if the oil temperatures are up above 80 will I do that. Oil sampling is your friend when in doubt after a season of questionable habits.

[wildebill308]

55 minutes ago, jleamont said:

Only if the oil temperatures are up above 80 will I do that. Oil sampling is your friend when in doubt after a season of questionable habits.

True, I have sample reports back to the first time I changed the oil on this engine. I am a firm believer in a full synthetic oil I am now running Shell Rotella T-6 5-40 to ensure good oil flow on start up. My last report showed fuel 0.2% and Blackstone shows an average number of 2.0%.

Bill

[rayin]

14 hours ago, jleamont said:

The flip side...How long at idle before departing in the morning? This is the one you hear the most complaints about.

I unhook, pack it all up, start the coach let it rise and build air, do a walk around the coach, hop in, buckle up and pull out, go easy on the throttle until it reaches operating temperature. 

That is exactly the procedure Cummins states in my engine manual. The days of having to warm up a diesel engine were prior to 1960. Isn't technology great. For those who still practice a 30 minute warmup, how do you warm up the Allison transmission too-as driving is the only way known; or do you just hit it and  forget about the transmission and differential?