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Smitty77 10-16-2015 09:55 AM

Not a C9, but with our CAPS ERA ISL in a 2004 coach, we start up and get to pressure, and air, and visual inspect of all gauges. Then slowly idle out of the park, and 'egg under the pedal' when accelerating until full temperature is reached. Usually about 5-7 minutes at easy highway speeds, and we're good to go. (And of course, we drive for safety and will step on it if a need arises, but generally try to avoid early punching of the throttle.).

I think it is important to know your engine in any RV you drive. For sure, different age an generations of engines, can have vary different needs for starting up and getting going. So for some, a warm up is advisable, while for others, a reasonable start up and go when all looks good - is also fine to do.

OP - Another welcome, and if you really want to test the varying opinions of the board members - post about Dino vs Syn, or Chevy vs Ford - now that always has some fun opinions:)!

I do suggest you ask the moderator to move this to the CAT section, as you might get more input.

Welcome again, and enjoy the new ride,

Coldheader 10-16-2015 04:34 PM

Thanks for the welcome to the forum. I have been on some other forums that get "spirited" replys as well. I usually end up laughing, so don't worry about it. We all have opinions, including myself, and we are allowed to voice them as it is America. I was already planning on getting it fully serviced with a new fuel filter as well as air filter. I hope that fixes it. If not, I guess I will have to take it to the next level. I do believe in warm ups myself however, usually just a minute or so to properly circulate oil and build up some heat in the combustion chamber. If it is 30 deg. outside, then maybe 5 minutes just to get some heat in the oil as well so that it isn't so thick. Warm ups just till the air is full may not be good for me. I have been shocked at how fast the air pressure comes up in this thing, probably 30 seconds. I was just looking for opinions as it didn't feel right to me. thanks

Rich-n-Linda 10-16-2015 05:58 PM


Originally Posted by macandphyl (Post 2785465)
You are supposed to let it idle until it warms up completely
before driving it. At least 5 minutes for my ISC, until the
temp gauge moves out of the blue range. Depending on
your gauge, I'd suspect 1/4 to 1/3 of the gauge range,
maybe more in cold weather.


There is absolutely no need to "warm up" a modern diesel. It does more harm than good. Check the Cat or Cummins manuals for the authoritative information on this. They will confirm this.

Just go easy on the throttle until she's up to temp.

2006 Mandalay 40E, Cummins ISL 400 HP

stuhly 10-16-2015 07:06 PM

Wow, so many Rocket Scientists.

sam60 10-16-2015 07:28 PM


Originally Posted by stuhly (Post 2786819)
Wow, so many Rocket Scientists.

What would you check first?

Just trying to help the fellow RVer.


Mike_Harriet 10-16-2015 07:39 PM

I always warm my diesels up at high idle 1000 RPM for about 3-5 min. Mostly to prevent excess piston slap and to get air up more quickly. Previously owned a 30yr old twin engine trawler with perfect diesels when I sold it. My background is heavy duty diesel equipment maintenance. Do as you feel comfortable with, but my very long lived diesels don't move before at least a 5min warmup at high idle.

chboone 10-16-2015 10:44 PM


Originally Posted by Mr. Hipster (Post 2786152)
Anti warm up guys, panties in a bunch today? Easy operation after air builds up is normally adequate. Keep the throttle mashing under control until thermostat opens, that's all.
Regarding the 'new tech' engines with urine in a tank and regen cycles and such, I'll stay with my vintage/repairable/affordable fleet, and plug them in @ night.

Nice looking coach.

DD788Snipe 10-17-2015 12:24 AM

X2 with Mike_Harriet. I would bet you had 3208s in that trawler. My 42' Californian has the the same. Great engines Mike. Ok, to the OP. Welcome to the forum. If your worried about getting heat into the engine try turning on your block heater the night before you leave the park. That what I do on those cool morning. I never idle mine longer than 5 to 10 minutes max, then take it easy for the first 5 miles. Who wants to hear a big diesel rattling away next door for any length of time in the morning.

Smitty77 10-17-2015 10:39 AM

Again, nothing wrong with people doing what they feel works for them. And again, older engines are different then newer engines. Both in electronic control's, and in closer engine tolerances.

As I mentioned, I do not do extended warming before heading out. I did not mentioned that we usually wait to power up the engine, before pulling in our slides, so that is a minute or so of running. I do bump up the idle RPM when starting to between 900-1000 RPM. And as someone else mentioned, if in extreme cold conditions, I will then let things simmer for a bit longer.

I'm probably no difference then many of you, having seen all kinds of procedures in campgrounds before taking flight. I do feel that many times our fellow travelers are clueless to how rude they an be while getting ready to go. Slamming doors, yelling info back and forth to each other are two of my lease favorite processes:)!

I also do not like a few that start their diesels, then go unhook their plumbing, and one gent packed his chairs away and rolled up his ground mat. This always seems to be a O'Dark'Early too:)!

I do not feel that I'm hurting my engine, or I would not do it, by getting up to pressure and validating all gauges are where they should be, and then slowly idling out of a park. If not in a pull thru, and still needing to hook up the toad, I will pull away from where I'm impacting my fellow travelers slumbers - and let the engine run as we hook up.

I belive more damage can be done to a hot engine, with lack of adequate cool down, then a colder engine doing light duty as it slowly warms up (And they do take sometime to get up to full temp!). I run our engine at rest stops, and at fuel stops. If going into a park after extended freeway speeds, I'm one of the guys that lets the engines run for several minutes to let the turbo and exhaust cool down. Using a combo of water temp and EGT readings, to determine this. A coked turbo, can be an expensive repair job.

Other then my personal dislike of those that excessively run an engine while getting underway in a crowded park, early in the AM - to each their own!!!!

Best to all,

gbburgess 10-17-2015 01:49 PM

Right or wrong guys, I warm up. It takes about 5 minutes to get air up and oil pressure down into the running pressure. During that time I check lights and hookup. Then I run out of the park at 5 mph and by the time I am to a real highway we are ready to speed up. As the last post indicated - cool down is really important - again 5 minutes coming off the interstate or a long hard drive. Fuel stops are a toss up. If I am in hurry - it runs while I fuel if not it is shut down until I need to pull forward.

Tha_Rooster 10-17-2015 02:20 PM


Originally Posted by Coldheader (Post 2785445)
I have a 2007 fleetwood with the CAT C9 400hp diesel. I just picked it up from a private owner and I am not sure if i have an issue or not. It has 22,000 miles on it. I start it up and warm it only for a minute or so, it idles great but occasionally when i take off it feels like it is "missing", it was very bad my last time out but other times hardly noticed it. It usually powers through it and after the motor warms up past 150 degrees, it runs very smooth. Is this an injector issue or do most of these larger diesels do this? My last diesel pusher was just a small and older 5.9 cummins but it never did this. I would think an injector issue would happen all the time, even when warm?

Mine is cold natured if you don't let it warm up is doesn't seem to have the power. I bought it new and it's always done it although it doesn't have to get to 150 degrees.

lanerd 10-17-2015 04:34 PM

Actually, in this case (warming up), what one person recommends or what another doesn't totally irrelevant.

Read you owner's manual and do exactly what it says. Very simple.

As far as the engine stumbling while cold, probably only a qualified technician would be able to know what is happening. This type of action can be an electrical, fuel, or even an air problem. Only the shadow knows......


Chiefly1 10-17-2015 08:48 PM

I have the same engine but mine purrs. I do warm my engine up while closing the slides, retracting the leveler's and then starting out slow. I usually hit the fast idle on the cruise control which helps with raising the temp unless I'm really close to someone rig and it's early. Try that first and see what happens.

Bill & Christine
40 ft Revolution LE Diesel Pusher & Honda Fit Sport
Sent from my iPad using iRV2 - RV Forum

DD788Snipe 10-17-2015 11:44 PM

Smitty is correct. Cooling down the turbo after a hard highway run is very important. The PO of my coach didn't do that and the replacement cost was $3800 for a new VVT.

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