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smd53 · 06-30-2022, 10:16 AM

Need your help. I bought my 2004 monaco windsor a year ago and it seems to always run water temperature 200-210. Washed out radiator stack with simple green HD side radiator. I spent time reading posts on this site on wax valve and looked at my engine bay and the valve. The valve number on the tage is 553109859110 after reading on a post that had all the different valve numbers I think when this was installed it's 212 degree valve. Thanks in advance for your help.

vito.a · 06-30-2022, 11:31 AM

Do you have the Sauer Danfoss electronic fan control, or the Sauer Danfoss mechanical fan control (wax valve)?

The electronic version gets inputs from the Cummins ECU to control the fan. Monaco
coaches with Cummins engines came with the electronic controller.

The mechanical controller is installed in one of the coolant pipes/hoses and is adjustable. Detroit and Cat engines came with a mechanical controller valve. Many of us with a failed electronic controller have replaced it with a mechanical.

jacwjames · 06-30-2022, 11:51 AM

Here's the parts page for my engine fan cooling, it has the part number for the thermovalve.

I had to replace mine in 2015, bought a replacement from Whitehouse products 553/1/09857/210

https://www.whitehouseproductsltd.co...857-210-thermo

But you have to register to get the price, last I heard it's about $270

I run at ~181F normal roads on hard pulls I'll go to ~195F but it drops right back down after the pull.

smd53 · 06-30-2022, 06:46 PM

I want to thank you for the information that you gave me. I will try to order the one that ends in 57. The previous owner had installed the wax valve it's braised to the outlet pipe coming from the thermostat to radiator. I will probably replace thermostat also looks original. Looking at some service records the cooling system was serviced by Cummins dealer and 50/50 antifreeze and water filter.

jacwjames · 06-30-2022, 07:25 PM

Almost sounds like your rig has had the Source Engineering thermovalve install. See picture on this link

Source Engineering Inc | Custom RV Chassis | Eugene, OR

My thermovalve is installed on the radiator.

shootist · 06-30-2022, 09:39 PM

The last number of the part number I thought was the temp opening. You cannot adjust the temp the wax plug melts at. Only the pressure against it. Iirc my part number ends in 190. Opens at 180, fully open at 192. https://www.whitehouseproductsltd.co...857-190-thermo
A pre egr motor is going to run a cooler thermostat and wax valve than a egr equipped motor.

shootist · 06-30-2022, 10:33 PM

As a note, my 04 dynasty came with the hydraulic controller mounted in the radiator. It is a non egr 400 isl. So Monaco maybe switched to the electronic controller in the common rail motors?

smd53 · 07-01-2022, 07:22 AM

I looked at the file from source engineering and that is what my setup looks like. I wonder if I replace the valve with a new one the threads are the same my guess they are. What a pain watching temperature gage instead of the scenery. I will setup the account and order one now.

jacwjames · 07-01-2022, 07:32 AM

I believe the thermovalve all have the same thread size.

smd53 · 07-01-2022, 07:37 AM

I wonder what is proper cooling range for the 400isl. My Cummins book that came with the mh says 180-200. I would like to see temperature running in those numbers hope new valve does it for me.

wolfe10 · 07-01-2022, 07:49 AM

Quote:

Originally Posted by smd53

I wonder what is proper cooling range for the 400isl. My Cummins book that came with the mh says 180-200. I would like to see temperature running in those numbers hope new valve does it for me.

When specing the fan control, it is very important that it is one that works in conjunction with your engine's thermostat.

You DO NOT want the engine coolant temperature to remain absolutely constant as you go to high-load conditions. Ideal is for fan to go to high ONLY after the thermostat is fully open plus a few degrees.

Were the fan control to be at the same or lower temperature than fully open thermostat, you would be wasting HP and MPG to needlessly run the fan at high speed.

So, for example if thermostat is fully open at 190 degrees F, I would want fan control to go to high speed around 195 degrees F.

smd53 · 07-01-2022, 07:58 AM

I thinking about the cooling problem could there be a flow controller that could be installed in the hydraulic lines that could be adjusted and used when the air temperature like we have in the phoenix area or driving grades. Just thinking

smd53 · 07-01-2022, 08:17 AM

That is good information on the temperature split. Looking at Cummins parts site using my engine serial number the part number 3940632 0pens at 180 thermostat but not full open temperature possible 200 don't know. There could be a phone call to Cummins to find out.

vito.a · 07-01-2022, 09:49 AM

My Sauer Danfoss mechanical wax valve has a plug on one end. With engine off, remove the plug and up inside is an adjustable shuttle valve. Use an Allen wrench and adjust it in/out to change the temp setting. Turning it out increases temp, in reduces temp. Use small increments, about 1/2 turn.

From a previous thread: A follow up on our thermo wax valve install. We made a 500 mile trip this week. Started with the wax valve at 4 1/2 turns out. Engine ran at 180-190. I turned it out 1/2 turn more with almost no difference. At the next stop I turned it out an additional 1 full turn. It then ran 210 plus. I then screwed the adjustment back in 1/2 turn and also topped off the coolant system reservoir. Now it runs from 195 to 205.

The temp will slowly climb to 205 climbing a hill and then the fans kick in and cool back to 195. We even climbed the steep mountain pass on I-15 north out of San Bernardino and it only went to 206 and then cooled back down. It's also nice when driving over a dirt road not to have a tornado behind us. The old Sauer-Danfoss electronic control ran both fans on high and it made a huge dust storm whenever we were on dirt.

Throttle response and fuel mileage are slightly better with reduced noise.