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Topic: Correct coolant thermostat for ISM 2003 U320? (Read 1482 times) previous topic - next topic

Correct coolant thermostat for ISM 2003 U320?

Is there more than one temp range on the ISM coolant thermostat? What is best recommended?  I plan to buy one to carry.    I'll take engine data #s when I buy thermostat. 

Cummins part  only? Or NAPA as well?  Part number?

I currently see 200 on the VMSPC for coolant temps in ordinary non stressed driving (flatlands/rolling hills, easy throttle, ambient temps 60s/70s).

May or may not install it right away.  Have 5 years on ELC coolant now, so may do soon or may wait one year.

Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: Correct coolant thermostat for ISM 2003 U320?

Reply #1 –
Take your engine #s to Cummings to get the correct t/ stat. 200 seems a bit high under normal load. Mine runs 180-190 on the VMSPEC unless in a hard pull for extended time.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: Correct coolant thermostat for ISM 2003 U320?

Reply #2 –
To get the correct parts for any Cummins you need the serial# and the, CPL# is the complete parts list for your engine.
The selected media item is not currently available.Bill&Doris 97 U270 36'
University of Parris Island Class of 66
Semper Fi  Build# 5174 MC#17094

Re: Correct coolant thermostat for ISM 2003 U320?

Reply #3 –
Dan, my 2001 ISM11 runs 178-179 under normal loads.  In the mountains it runs 189-195.  I do not know what tange is acceptable.for the ISM11 but Cummins can tell you.  Your radiator configuration, the stuff in the radiator stack, the body side panels, cooling fans speeds and other things all mighe be different from mine and affect coolant temp.  I woukd ask your Prior Owner what their experience was.  It might be normal for that coach.  I would get a Cummins thermostat.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Correct coolant thermostat for ISM 2003 U320?

Reply #4 –
I do not have a VMSpec, but per the Cummins Digital Information Center on the 2003 the coolant temp normally runs 179 to 181 on non-stressed conditions.

I do have a small coolant leak coming from the thermostat area that I will fix when the coach comes out of storage for the winter. So, I will likely be putting in a new thermostat along with the leak repair.
2003 U320 4010 - SOLD
2014 RAM 1500 Ecodiesel

Re: Correct coolant thermostat for ISM 2003 U320?

Reply #5 –
Dan, my coach also runs at about 180 degrees under normal operating conditions. If you download the Cummins Quick Serve mobile app and enter your engine's serial number it will let you look at all of the parts for your engine.

For mine it calls for p/n 3335550 which begins s to open at 180 degrees and is fully open at 201 degrees.
Steve & Sandy
2003 U320 4220 WCDS, build#6160
Motorcade #17794
USMC '67-'71

Re: Correct coolant thermostat for ISM 2003 U320?

Reply #6 –
This may sound dump but don't forget to

get a gasket and maybe an extra when

you get the t-stat.

Carter-

Re: Correct coolant thermostat for ISM 2003 U320?

Reply #7 –
Thanks for all the info.  I knew about the quick serve on line, but it is partially down for maintenance.  The Android phone app for quick serve Cummins is great!

The data plate just underneath the valve cover on passenger side was a bear to see.  Using a flashlight, cell phone for photos, wet rag, and temporarily pulling two bolts holding the wiring harness in place I was able to get good photos of the data plate.

My CPL is 2608, engine build was 05/02.

My thermostat is also 3335550, plus gaskets 3335548, 3335549.  Also temp 180/201.

I am a long ways from any Cummins, NAPA has the thermostat for $72. (minus military discount).  I'll be looking it up online later today.

I figure either the thermostat is at issue, or the temp sender.

Thanks again,
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: Correct coolant thermostat for ISM 2003 U320?

Reply #8 –
I found many crossover part numbers today for ISM Coolant Thermostat: 4318947 2952204, 3335550, 4973373, 2882757, 4318197

Operating Range: 180 - 201 Degrees

Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: Correct coolant thermostat for ISM 2003 U320?

Reply #9 –
Follow up:  My main goal was to stop a minor coolant seep/leak on the rear header tank of the side radiator.  I had thought about all fresh coolant and a new coolant thermostat while I was at it.

I decided against installing a thermostat in our campground. It doesn't look like too easy of a job (but doable in the correct environment). 

 What I did instead was tighten the bolts I could get to on the radiator rear header (see link to older thread here: Tightening bolts to fix coolant leak )  I still had a minor seep after doing so.

Next I drained two  gallons of the Rotella ELC Coolant, used 4 packs of Barrs HDC stop leak tablets mixed thoroughly  in new coolant (4 packs are for treating 12 Gallons): Radiator Leak Repair | Repair Radiator Leak .  I have the 16 gallon capacity cooling system.  The 2 gallons I drained looked perfect, clean, no contamination at all.

Topped up with fresh  Rotella ELC coolant, turned the coolant filter to off, and fast idled for about 45 minutes to temp 180 on the coolant per VMSpc.

Coolant seep is totally gone.  3 packs of tablets (treats 9 gallons) would likely have accomplished the same task, since the 4 packs worked so quickly.  I have a extra pack to carry with me.  I will wait until after our next move of 160 miles to turn the coolant filter back on. 

I did source the gaskets and thermostat needed, as below. Don't forget the housing gasket if you decide to change out thermostat.  I may order this in our next location to carry on board as spares.  We will be due a coolant flush and new ELC in 2018 (6 years change-out)

DIESEL PRO POWER, INC.
760 N.W. 4th STREET SUITE 100
MIAMI,FLORIDA. 33128
T:(305)545-5588 F:(305)545-9557
DATE: 03/15/17
SALESREP: KESNER
PO NUMBER: ISM SPARES
================================================================================================
DESCRIPTION                                    QTY        PRICE        AMOUNT
================================================================================================
THERMOSTAT 180F,82C                      1        27.12          27.12
SEAL, THERMOSTAT                            1          6.91            6.91
THERMOSTAT HOUSING GASKET        1          5.88            5.88
SUBTOTAL                39.91
7% TAX                  2.79
TOTAL                  42.70
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide
 

Re: Correct coolant thermostat for ISM 2003 U320?

Reply #10 –
Just as a heads up for those who will be tightening those bolts in the future; it is important to get a wrench on the nut for each of the bolts.
Dick, '03 U320 40' Tag, 2 slides, Coach #6075
Full Timers
2009 Honda CR-V