First Diesel Pusher

[Chunkybeastracin@aol.com]

We just purchased our first diesel pusher RV, a Beaver Monterey with a cat engine. Just a little confused on the starting procedure and especially in cold weather as we live in Colorado. Was told to always let warm up to operating temp before driving but saw other articles that said not to let idle for longer than 10 minutes as engine damage can occur. Noticed the dash does have a light that comes on saying engine preheat and after some idle time that light goes off. I assume that show safe operating time to drive.

I also noticed that when it was extremely cold around 8 degrees when I put the trans in D and applied gas nothing happened, in neutral the gas pedal would allow to change the rpm. After additional warm up when placed in D the coach moved just fine. Sorry about the stupid questions but I am new to this style of coach, while I am excited to finally have a pusher, I feel lost on alot of operating things of this coach

Thank you for any help, Mike and Lori

[Jackhal49]

I have a 05 Journey with a 350 Cat. To start mine you turn the key to accessory a light on the dash will light saying "wait to start engine" when that goes out you can turn the key to start the engine. Mine also says not to idle the engine in low idle for more than 10 minutes, however, you can set the cruise control to 1000 rpms to idle longer. I have not had any problems with putting the trans in D and driving off, however, I have never driven it in very cold weather either. May want to check your Allison transmission manual, I do not remember seeing anything about cold weather operation. This is my first diesel as well and have had the Journey just over a year. I think you will love it! Quiet driving, the engine brake is awesome going down steep grades, and the ride is awesome. Congrats on your new DP! Good Luck and Happy RVing!!!

[wolfe10]

While you should read your Engine Owners Manual for specific protocol, here are the basics for all modern diesel engines:

If below 40 degrees or so, use the block heater (shore power or generator) if available. Turn it on 1-3 hours before starting, depending on ambient temperature.

Most engines have an intake manifold heater, so there is a "wait to start". On some, in very cold temperatures, you cycle the key on then off, then on again to fully heat the intake manifold, on others you just wait for the light to go out (this is where reading your Engine Owners Manual comes in).

Once started, after 30 seconds or so you can use the cruise to raise the idle to high idle for quicker warm-up and air pressure build.

Once the temperature gauge starts moving off the cold peg, you can begin moving. Many engines, including your Caterpillar engine have a built in "de-rate" when very cold, so their is little power at very low temperatures. This feature was designed to keep truck drivers from jumping in and flooring a completely cold engine and doing damage. If this persists past the time that the temperature gauge moves off its cold peg, take it to a Caterpillar dealer for a checkup.

And no need to let it get completely up to operating temperature before driving, UNLESS you are immediately jumping up to freeway speeds. Said another way, low speed operation in the CG and city streets does not require a fully warm engine.

Brett Wolfe

[Chunkybeastracin@aol.com]

Thank you guys, I really appreciate your advise. I have to admit that coming from entry level gas RV's to a diesel pusher at first seemed overwhelming at first with all the new procedures, water/gas separators etc. I thougth that maybe I got in over my head but now things are making more sense.

I skimmed throught the 300 plus page owners manual and found a 24/7 catapiller help line and they also helped answer quaestions which I found to be really nice that they stand behind their product even on a used coach like mine.

Thanks again for your help

[wolfe10]

Thank you guys, I really appreciate your advise. I have to admit that coming from entry level gas RV's to a diesel pusher at first seemed overwhelming at first with all the new procedures, water/gas separators etc. I thougth that maybe I got in over my head but now things are making more sense.

I skimmed through the 300 plus page owners manual and found a 24/7 Caterpillar help line and they also helped answer questions which I found to be really nice that they stand behind their product even on a used coach like mine.

Thanks again for your help

You might want to consider joining the Caterpillar RV Engine Owners Club, an FMCA Chapter. http://catrvclub.org/

And the Club's technical website (one of the Yahoo Groups): http://autos.groups.yahoo.com/group/CATRVClub/

Lots of fun AND you will learn a lot about the mechanical parts of your coach.

Next Rally with Maintenance Seminars is in March before the FMCA Convention in Albuquerque. I understand there are still some spots available.

Brett Wolfe

[Chunkybeastracin@aol.com]

Thanks Brett, I also had a question on using the exhaust brake. I did read some of the other brake related topics on the forum. When I turn on the exhaust brake it slows the coach down to a comfortable speed for the decline but than it seems to down shift or slow it down further which turns out to be too slow for the hill so I have to apply the throttle to gain a little speed. Am I doing something wrong or is the exhaust brake set up to slow down to a certain speed and than when rpm settle down it slows down further?

[wolfe10]

Thanks Brett, I also had a question on using the exhaust brake. I did read some of the other brake related topics on the forum. When I turn on the exhaust brake it slows the coach down to a comfortable speed for the decline but than it seems to down shift or slow it down further which turns out to be too slow for the hill so I have to apply the throttle to gain a little speed. Am I doing something wrong or is the exhaust brake set up to slow down to a certain speed and than when rpm settle down it slows down further?

You are not doing anything wrong. And the transmission is doing exactly what it was programmed to do.

The chassis maker tells Allison what PRE-SELECT GEAR they want programmed into the Allison ECU for the exhaust brake. The pre-select gear is the gear that the transmissions down-shifts TOWARD (not directly to) when the exhaust brake in engaged. That gear will show up in your left (two window display) or only (single window display) shift pad (i.e. the display will go from "6" to the pre-select gear).

Commonly chosen pre-select gears are 2nd and 4th. BUT, ANY GEAR MAY BE PROGRAMMED IN-- YOUR CHOICE. The cost of reprogramming is usually under $150 at any Allison dealer.

Choosing a low pre-select gear (like 2nd): Advantage-- great for coming to a complete stop. Disadvantage-- exactly what you are asking about.

Choosing a high pre-select gear (like 5th): Advantage-- gives driver complete control of gear selection for matching braking HP to the grade. Disadvantage-- driver must use the down arrows to select lower gears for steeper grades or coming to a complete stop. One does NOT have to be careful in pushing the down-arrow-- you can not cause it to over-rev the engine. In fact a second gear pre-select and a 5th gear pre-select where you hit the down arrow to select 2nd gear are EXACTLY the same as far as how the transmission operates.

I grew up on stick shifts and we do a lot of technical mountain driving. We had our Allison ECU programmed for 5th gear pre-select.

Until/unless you have it re-programmed, here are several fine-tuning recommendations:

Learn to apply just enough throttle to cancel the exhaust brake.

Use the down arrow to lock the transmission in the gear you need (so it won't up-shift when you apply a little throttle). As an example, if your are descending a grade in 4th gear with the exhaust brake on and that gives too much braking HP, by selecting 4th gear with the down arrow, you are toggling between 4th gear and 4th gear with exhaust brake on, rather than between 4th gear with exhaust brake on and 5th or 6th gear with no exhaust brake as soon as you hit the throttle or turn off the exhaust brake switch.

Turning the exhaust brake switch on/off/on....... is another way to fine tune your speed of descent. And until you touch the throttle, the transmission will not up-shift from the gear it was in when you went from exhaust brake switch on to off.

A lot of this is practice. These fine-tuning techniques that will become second nature as you practice them.

Brett Wolfe

No right or wrong answers here-- it is a matter of personal preference.