What is normal for 5.9 water temp?

Just look at them side by side, the Cummins stat is a very nice HD unit.

I would expect reading external metal temp of the water pump would result in a far lower temp than actual water temp.

FYI good choice. The non factory stat will give you trouble. I replaced one in my 98 3 times before I payed up. Slow learner.

45Ricochet wrote:

path1 wrote:
I have no idea why Cummins was so much. Maybe someone on here can tell. Cummins t-stat on right part number 3946849 and brand X on left. (pic from another site)

IMO the Tstat don't make much of a difference, I mean the OEM Cummins part only lasted that few of miles anyway. How bad can the RMAN be?
Now the water pump is a different story :W Cummins only in my book just because it's soooooo hard to replace :W :W :R :P
Kidding aside the RMAN pumps are c**p.
Either way you can recover the coolant easily with the Tstat, the pump is a bit more of a challenge unless you have a bunch of buckets.
Personally I just replaced mine before they went south this year on it's second coolant change.Dang the guy who bought it was indeed a Lucky Buyer!

I did put in the $$$ one. If you type in that part number, some postings on different forums as to why so much. In tech manual looking up spec on bolts they make reference to "quality commercial" t-stat. New t-stat looked different so had to confirm by engine number.
And Anyways...this might help you later, if not already done. Cummins NW keeps track of what you bought back to 1998. I've have 2 pages in their computer over the years. Today they gave me a "account number" and under that they have a space and added my engine number of 5.9 and the Onan serial number and what spec that's in my class C. Now if I need it they have it on hand and more importantly, I can call them when out of their area to get info if needed. I think they go south to Medford (all most CA line) and over to MT. At any rate don't have to go thru the hassle especially on Onan and what spec and model and number etc. (Don't like their prices though)

All good now 185-190

path1 wrote:
I have no idea why Cummins was so much. Maybe someone on here can tell. Cummins t-stat on right part number 3946849 and brand X on left. (pic from another site)

IMO the Tstat don't make much of a difference, I mean the OEM Cummins part only lasted that few of miles anyway. How bad can the RMAN be?
Now the water pump is a different story :W Cummins only in my book just because it's soooooo hard to replace :W :W :R :P
Kidding aside the RMAN pumps are c**p.
Either way you can recover the coolant easily with the Tstat, the pump is a bit more of a challenge unless you have a bunch of buckets.
Personally I just replaced mine before they went south this year on it's second coolant change.Dang the guy who bought it was indeed a Lucky Buyer!

rhagfo wrote:

Old-Biscuit wrote:
Hey 'path1'

Have you changed that coolant before......

At 15 yrs you should be on 3rd coolant change

100K or 60 months is 'schedule' for that HOAT coolant.

2nd gen just use plain old green/yellow anti-freeze.

Forgot 3rd gen didn't come about until 2003 :S

rhagfo wrote:

Old-Biscuit wrote:
Hey 'path1'

Have you changed that coolant before......

At 15 yrs you should be on 3rd coolant change

100K or 60 months is 'schedule' for that HOAT coolant.

2nd gen just use plain old green/yellow anti-freeze.

Changed anti freeze year and half ago. Mechanic from where I retired from and Cummins dealer said this was I should use. https://www.cumminsfiltration.com/html/en/products/cooling/coolant/es_compleat/es_compleat.html

Old-Biscuit wrote:
Hey 'path1'

Have you changed that coolant before......

At 15 yrs you should be on 3rd coolant change

100K or 60 months is 'schedule' for that HOAT coolant.

2nd gen just use plain old green/yellow anti-freeze.

I have no idea why Cummins was so much. Maybe someone on here can tell. Cummins t-stat on right part number 3946849 and brand X on left. (pic from another site)

Hey 'path1'

Have you changed that coolant before......

At 15 yrs you should be on 3rd coolant change

100K or 60 months is 'schedule' for that HOAT coolant.