Community Forums

gweedo295 · 07-11-2018, 07:41 AM

Thank you Mike for the video, interesting, once again a contradiction to others opinions. I will check to see if Cummins has any info on idling.

I purchased my rig two years ago with 38K, it now has 50K, I just changed the oil and filter for the 4th time, (I know anal) thus far I have no blow by and I haven't had to add any oil at all between changes. I have been running Rotella, this time around I am trying the Rotella T5 Semi Synthetic.

So since this video says you really shouldn't idle but if you do, idle at a higher RPM. I think the happy medium to avoid the heat up and cool down regarding the exhaust manifold, it would be okay at a rest stop to idle for a few minutes.

Thanks again for the video,

JohnBoyToo · 07-11-2018, 08:35 AM

Quote:

Originally Posted by gweedo295

1. Do you always have your exhaust brake on? Yes

2. Should it be off while traveling down the road or does it matter I leave it on... Doesn't matter since am usually on cruise control and then it does not activate until braking or off throttle

3. Do you use it in city traffic - especially in town for better emergency braking when that doofus pulls out in front of our 40k+ lb convoy !

4. What RPM do you maintain while descending a hill with it on - depends on the size of the hill, but no more than 2200 usually

good luck on your decision...

gweedo295 · 07-11-2018, 02:26 PM

So I went onto Cummins quick serve. Here is what it states regarding idling an engine for any period of time. Hope this helps.

CAUTION

Do not idle for extended periods of time. Excessive idle time can cause poor engine performance.

Internal combustion engine s must not operate at low idle speed for extended periods of time. This operating condition may lead to poor engine performance. The idle shutdown feature, available on most Cummins® engine s, can be programmed to shut the engine down after a period of low idle speed operation with no driver activity. A flashing warning lamp will inform the driver of an impending shutdown. If an engine must idle for an extended period of time, it should be done at fast idle (1000 rpm or greater). The Power Take-Off (PTO) feature, available on most Cummins® engine s, can be programmed to adjust engine speed with the use of OEM switches to pre-programmed set points.

JohnBoyToo · 07-12-2018, 08:04 AM

Yes, and what does it say about the cummins engines in the generators that run 24/7/365 ? they idle a lot too... to each his own, but I'm going on 40 years running diesel engines in pickups, rv's etc and never bothered with how I idled...

We have a tendency to overthink things that others have done when it's our first time at it and just wanting to do it 'right' !

BUT, I don't start the vehicle and go watch a movie

in fact, I'm the guy that does everything else, gets in, starts it to idle long enough to air up and then it's in gear and driving easy until it warms up...

gweedo295 · 07-12-2018, 08:23 AM

I agree John, I turned wrenches at a shop for a few years and I have always done my own maintenance and repairs unless it was beyond my capabilities. I have owned pickup truck diesels but never an RV. Yes I do things right best I can.

I am a true believer in warming up an engine before taking off. If I had to chose from what a book says or a true experienced diesel mechanic of many years, I would go with the mechanic for the most part.

Thank you everyone for your input and ideas throughout this post. Undoubtedly I'm sure something else will arise and I will return to the place that knows best. thanks again!!

super_rep · 07-15-2018, 07:34 AM

I have to agree with both John & Pat. My Jake brake switch is always on. However I have a separate button on the floor that I must depress with my left foot before the Jake will engage. I always use the Jake first to slow down and then the coach brakes to stop. Unless it's an emergency, every stop I make is Jake first and then coach brakes.

Using the Jake greatly reduces the wear on the coach service brakes. I put 144,000 miles on our previous coach - a Beaver Marquis with a CAT C-12 - and still had 65% brake lining left. We now have 121,000 on our present Monaco - Detroit Series 60 - and still have almost 80% brake pads remaining. Another advantage of always using the Jake first is the fact that I have no cracks in my brake rotors - a common symptom of over heated brakes that has occurred on many coaches.

pmccharles · 10-28-2023, 01:05 PM

its oct 2023 so your post is awhile ago. We have similar questions about using the engine brake 350 isl 2006 newmar we are in sodona. Down from alaske using engine brake frequently rpm at 2200 to 2500 sometmes feels like lots of engine use but saving brakes and necessary as coach is 32000 lbs and tow vechile. Now engine is screaming screetching off and on let off gas to 50 or so it will stop but will start at any given moment. Repair in Tuscon on Tues morning 200 miles away. is it the exhaust manifold or exhaust issue OR is a turbo waiting to get sucked into the engine. Drive 200 miles ok or Not . If you are still around please let me know your thoughts.

wolfe10 · 10-28-2023, 01:11 PM

Quote:

Originally Posted by pmccharles

its oct 2023 so your post is awhile ago. We have similar questions about using the engine brake 350 isl 2006 newmar we are in sodona. Down from alaske using engine brake frequently rpm at 2200 to 2500 sometmes feels like lots of engine use but saving brakes and necessary as coach is 32000 lbs and tow vechile. Now engine is screaming screetching off and on let off gas to 50 or so it will stop but will start at any given moment. Repair in Tuscon on Tues morning 200 miles away. is it the exhaust manifold or exhaust issue OR is a turbo waiting to get sucked into the engine. Drive 200 miles ok or Not . If you are still around please let me know your thoughts.

Is this a Cummins ISC with exhaust brake (common for the 350 HP)
OR
Cummins ISL with exhaust brake? OR Cummins ISL with engine compression brake?

Not sure we can arm chair diagnose the noise. Have you looked for signs of loose or cracked exhaust manifold?

And, either engine is OK at those RPM's under no load/closed throttle.

dca81 · 10-28-2023, 03:57 PM

Well, do not know if this helps but I started a small trucking company after retiring and blew 2 turbos on my trucks (Cat 3126 and Detroit diesel 60 series). Mechanic told me to let my rig idle at least 5 min after stopping to allow oil on turbo bearing to cool down. Actually suggested unless I had an extended stop to just let the engine idle (eg fuel fill). So basic question seems to be what is "excessive" idling?
Just my ignorant $.02 Do accept if I am idling I should kick up the RPM

96 Wideglide · 10-30-2023, 10:11 AM

The older pre-emissions engines were not bothered by extended idling, like a modern diesel!

dca81 · 10-30-2023, 12:11 PM

Thanks for the additional information. The OP had a 2007 ISL is that pre-emission enough to allow reasonable idling (say periods of 10-15 min or less)?

YC1 · 10-30-2023, 01:38 PM

Cummins reps say leaving the freeway and driving to a fuel station is enough cool down and do not recommend idling.

I think if you are hammering the VRT, variable ratio turbo, (which is likely on the 2207), that a lower gear would be in order to keep the rpm's down a bit.

96 Wideglide · 10-30-2023, 01:57 PM

Quote:

Originally Posted by dca81

Thanks for the additional information. The OP had a 2007 ISL is that pre-emission enough to allow reasonable idling (say periods of 10-15 min or less)?

I think an '07 ISL will likely have EGR which will have problems with extended idling.
10-15min should be fine!

wolfe10 · 10-30-2023, 02:12 PM

Quote:

Originally Posted by dca81

Thanks for the additional information. The OP had a 2007 ISL is that pre-emission enough to allow reasonable idling (say periods of 10-15 min or less)?

That is WAY too long. Idle time is just to cool the turbo-- so if driving at very low speed in a CG, you can shut it off immediately.

If you just pulled a long steep grade and pulled into a scenic overlook, 4-5 minutes.