Engine water temp-What is considered high?

[frankiebIII]

Hi all,
I have a 2005 Monaco Diplomat with a 400 hp Cummins diesel, I have owned it for 4 years. It has been problem free and runs great. However, the 4 times I have taken it over the Grape Vine steep grade the engine water temp creeps up over the 200 marker. When it gets to about 225 I start to hear a faint squelching/light beeping sound from by my left leg. As it gets to about 230ish it becomes a full blown beeping sound like when a car door is left open on an automobile. No warning lights come on and my RV is equipd with a engine warning light, a check engine light and a Stop Engine light. As I go down hill the beeping slowly fades as the engine cools until it goes to a light squelch and then disappears. I am assuming this is some sort of warning.

Is it a warning?
Does anyone else get this warning?
Is my engine running too hot?
What can I do to bring the temp down when going up a hill as I do have the peddle all the way down? Should I drop my speed to a crawl like the semis do?
Should I pull over and let engine cool and if I do that do I rust sit and let it idle or turn off engine after it idles a few mins?

Thanks for any education you can offer!

[wolfe10]

usersmanual wrote:


a 2005 400HP ISL Monaco diplomat is a side cooling unit

Then cleaning the CAC from the outside is all you need. And Simple Green EXTREME is the recommended product-- it is Aluminum-friendly. It was developed for degreasing aluminum aircraft.

[usersmanual]

wolfe10 wrote:
Is this a rear radiator?

If so, you need to clean the FRONT of the Charge Air Cooler from the FRONT (access from bedroom/closet--whatever gives you access to the front of the fan shroud).

The only exception is if you have a "stacked" CAC/radiator instead of a "sandwiched" CAC/radiator with the CAC in front of the radiator.

Cleaning from the back with a sandwiched cooling package may make one feel good, but the VAST percent of the dirt and debris will have been "filtered" out by the CAC.

a 2005 400HP ISL Monaco diplomat is a side cooling unit

[wolfe10]

Is this a rear radiator?

If so, you need to clean the FRONT of the Charge Air Cooler from the FRONT (access from bedroom/closet--whatever gives you access to the front of the fan shroud).

The only exception is if you have a "stacked" CAC/radiator instead of a "sandwiched" CAC/radiator with the CAC in front of the radiator.

Cleaning from the back with a sandwiched cooling package may make one feel good, but the VAST percent of the dirt and debris will have been "filtered" out by the CAC.

[rgatijnet1]

frankiebIII wrote:
I checked the radiator and there are a few bent fins and it is somewhat black but I can see through it. I'll clean with simple green today.
There is also an electric outlet in the back engine compartment with a plug hanging nearby but not plugged in. I'm assuming that is for a device that heats the engine in cold temps correct?

Use the Simple Green Extreme, not just the plain Simple Green. The SG Extreme is made for aluminum and the plain SG will start to corrode metal if even a little bit of it is left when you rinse things off. Since it is next to impossible to thoroughly rinse a radiator, use the right product instead of possibly creating another problem.

[Mr_Mark1]

Frankie, I would think it's the block heater cord/plug. It is recommended that when you are not using the engine block heater, to keep the plug 'out' of the socket (seem like I remember reading in our previous Monaco manual). I think the reason is, so that grime doesn't get into the unused plug-in.

While using it in the winter months, I put one of those child-protection inserts in the bottom plug so that I wouldn't have to unplug the heater so often and it would keep the grime out.

MM.

[GoPackGo]

Where, exactly, is it ?

[frankiebIII]

I checked the radiator and there are a few bent fins and it is somewhat black but I can see through it. I'll clean with simple green today.
There is also an electric outlet in the back engine compartment with a plug hanging nearby but not plugged in. I'm assuming that is for a device that heats the engine in cold temps correct?

[Kayteg1]

When checking cooling system and going up on lower gear is always good advise,
Grapevine grade is famous for vehicle cooling system killing, or at least testing.
SB it is 7 miles long, NB it is about 11 miles long up grade.
With summer temperatures reaching 100F and pressure to keep at freeway speeds it is very easy to go overboard.
How many 4-lines freeways you see with 35 mph speed limit for trucks?
Only because of grade

[JumboJet]

rgatijnet1 wrote:
What may also be of some concern is that when the engine temperature goes up, the transmission fluid also gets hotter. Best to keep them both lower.

The transmission heat creates coolant heat. My transmission cooler is built into the bottom of the radiator. Heat rises.

I saw 215-220 climbing up several large mountain passes on I-90 etc. in July.

[Mr_Mark1]

Frankie,

As mentioned, I would definitely have the radiator set-up cleaned. You can do this yourself with Simple Green and a water hose (do not use super high pressure that will bend the fins).

Spray the Simple Green (several versions made, pick the best for your application) generously and let it sit. You can repeat this several times. If there is any way that you can hook up to hot water that would be a plus.

Your coach is almost 12 yrs. old, your radiator could be pretty dirty if it has never been cleaned.

Good luck,
MM.

[Sam_Spade]

frankiebIII wrote:


What is the gear I should be in to climb the Grapevine grade?

You really should learn to check the fluids yourself; oil, water and transmission at a minimum. Doing so might save you a TON of money down the road.

He was trying to tell you that cleaning out the radiator might help.

You should be in whatever gear gets your engine speed back to where it normally is for highway cruising, probably around 2000 to 2500 RPM or a bit more. It is possible, and likely even, that the transmission might downshift for you and no manual intervention will be necessary.

But then.....if that is already happening....the transmission is downshifting AND the speed is falling AND the RPMs are going up AND it is still getting hot (above 220) having the cooling system serviced probably is a good idea, for piece of mind if nothing else.

[Strabo]

Grapevine.....I get the best Running start I can, stay clear of slow trucks, and turn ac off, cross fingers, Pat dash saying....Good Girl.

Max average speed, 40. Coolant temp, 220. Once we get to the top she cools off. Clutch fan is engaged.

But then again we have a 6.0 psd

[tatest]

Depends on the coolant mixture and coolant system pressures, which are essentially manufacturer specifications. Way back when it was 50-50 water and ethylene glycol, running 15 PSI, 240 F was considered hot. More modern coolants can go higher, but the engine manufacturer might not want that (though higher cylinder temperature means greater Otto cycle efficiency).

If a warning system is beeping at you, it means too hot, according to manufacturer's specifications. Get the cooling system checked out, make sure you have good air flow through the radiator, and coolant flow isn't blocked. If it is heating up climbing, gearing down for higher RPM gets you more coolant flow, shutting off chassis air conditioning might reduce the heat load vs air flow.

[time2roll]

frankiebIII wrote:
What is the gear I should be in to climb the Grapevine grade?

What gear are you in? Go one gear lower. May require slowing a bit depending on RPM.

What RPM? Aim for just above peak torque rpm to half-way between peak torque and peak HP rpms. (see owner's manual)