1999 Monaco Diplomat - 275HP Cummins Max Safe Engine Temp

[ereadingrv]

Hi, Folks...

We have a new (to us) 1999 Monaco Diplomat with the 275 hp ISC Cummins.

This weekend, we spent some time in Palm Springs (near Los Angeles), and the average temperature seemed to be about 94. This evening, we made our way to Sam's Family Spa in Desert Hot Springs. Even though it was dark, the temperature seemed to hover right at about 219 degrees. This is on the edge of the red zone, but higher pretty much than I've seen it before.

Fluids are fairly good. We seem to need a quart of oil, which we're adding tomorrow (we're parked now) when it's light.

My question is: is that a dangerously or unusually high operating temperature for the weather conditions here? Any recommendations for bringing the temp down?

Thanks much!

[walt2137]

Have you cleaned the radiator, the way the CAC and radiator are installed in the 99 Dip along with the crankcase vent does cause problems, first check to see if the vent off the engine has been routed further to the rear to where the engine fan can't pick the oil smoke up and coat the CAC and radiator, use a hose to rout back next the gauges on the coach are not accurate I used a Silverleaf system when we had the Dip to read engine and trans computer. Go to this link check the last post there is a link click on it to get the procedure to clean the radiator.
http://www.irv2.com/forums/f115/hr-radiator-250430.html

[ereadingrv]

We have not cleaned the radiator, no. We will look into that. We may need to have a pro do it, as we're not especially "handy" people. We can write you a fine novel or consult on marketing strategies, but sadly, we tend to be all thumbs when it comes to mechanical things.

That said, we're going to look over the instructions in your great, detailed document. Thank you for sharing it. Perhaps it is something we'll be able to do without an issue.

Another issue, I think, is that we can't really do that here at Sam's spa. So we will need to determine how it will run getting us back to L.A., where we can have the work done.

[walt2137]

Sounds like the Silverleaf VMSpc program would be of a big help to you, go to the link I will post to read about it , you can download the program free to your laptop to play with it only the equipment that plugs under the dash cost cash and RV upgrades generally have the best price, I am not connected with this company only been using the VMSpc since 2001 and would not want to travel without the system. The gauge package on our Monaco coaches is often referred to as a entertainment center.

VMSpc Downloads | SilverLeaf Electronics, Inc.

[ereadingrv]

Hi, Walt...

We've actually looked into the Silverleaf. We saw one pretty cool thread where someone installed it on a Windows tablet, then mounted the tablet semi-permanently on their dash. I think that's the approach we're going to take with it. Just a matter of getting it done!

[walt2137]

It was one for sale in classifieds.

[OLYLEN]

Another cheaper option is the scan gauge D. About $160 and it is plug and play. Reads everything the coach puts out and setup is less than the Silverleaf and you don't need a laptop or tablet. Plugs it same as the Silverleaf.

LEN

[walt2137]

Yes Len but it does not do what a VMSpc can do, susgest you read the thread on this forum on the Silverleaf VMSpc.

[avfordguy]

My last coach was the same as yours, with the 275 ISB, what I can tell you is that Monaco had some poor engineering people, as the radiator is behind the CAC ( charge air cooler) engine cooling is very marginal in 100+ temps. We used to run the palm springs, lake havasu, las Vegas, runs all the time when we lived in SoCal, with that said I would have the radiator cleaned as best it canbe done still installed in the coach, mine was so bad that I had to remove it and clean it, and the cac. One other word of advise is that the dash gauges on my old 99 were really inaccurate, coolant temp was always 15-20 degrees hotter than what the silver leaf would indicate.

[ereadingrv]

Hi...

Thanks for the info. It's nice to hear from someone who has actually BEEN in the same areas we were traveling through, in the same coach we have!

That said, the info about inaccurate gauges, which Walt (or Will?) also alluded to in one of the above posts, is really useful. And a little alarming.

As for the radiator, we looked at it today, and it is actually pretty much pristine. So that does not appear to be the issue. It sounds like the real problem is just, as you say, bad engineering. But when a coach is new to you, it does give you heart palpitations when you think, "Oh, man, I might be about to blow up the engine of my new coach!"

[VegasFoodGuy]

Originally Posted by ereadingrv

Hi...

Thanks for the info. It's nice to hear from someone who has actually BEEN in the same areas we were traveling through, in the same coach we have!

That said, the info about inaccurate gauges, which Walt (or Will?) also alluded to in one of the above posts, is really useful. And a little alarming.

As for the radiator, we looked at it today, and it is actually pretty much pristine. So that does not appear to be the issue. It sounds like the real problem is just, as you say, bad engineering. But when a coach is new to you, it does give you heart palpitations when you think, "Oh, man, I might be about to blow up the engine of my new coach!"

I have same ISB, Did you look from bedroom side of radiator? Clean it anyway, from bedroom side.

Terry

[Rburian]

All the debris is collected on the engine side of the radiator, My pervious 2000 Dip was running hot , I could not believe what came out during steam cleaning with simple green. After, ran much cooler.

[WesPearson]

Same engine in my 98 Endeavor. The shop removed and cleaned the CAC and radiator and had a new surge tank made. They extended the slober tube to the very rear. Drove from OC to Vegas With an OAT of 100+ degrees. Never got over 195 degrees on my VMSPC. Don't skimp on the cooling system. The 5.9 275 Cummins can handle a lot of heat as long as you keep the cooling system clean and don't lug the engine on the grades.


1998 Holiday Rambler Endeavor 38 Ft. 5.9 Cummins ISB 275 HP

[ereadingrv]

Hi, Wes...

What shop did the work for you?