Thermostat experiences minus big C.

["Mad Max"]

I'll add this too -



In the initial testing with the new engine... while revving the engine and before the t-stat opened, I noticed the upper rad hose constricting as a result of the pump sucking hard on the system. I didn't like that at all as it's just an opportunity for a new leak... so I pulled the t-stat out, drilled three 1/8" holes in it, and that will relieve the pressure in the system for every time the engine warms up. Then when warm the t-stat opens and the system does its thing and the holes will be irrelevant.



As well, when filling the system from empty, the holes will allow the head to fill completely, eliminating the possibility of a steam pocket to form on the back side of the t-stat... . badbad for gaskets.



... just some of the voodoo that I do...



- M2

 

[WKruger]

Hmmm, run a cheap t-stat, overheat the engine, cause some sort of damage, and have DC blame the t-stat and void the warranty. I'd rather spend the $30 and get one from Cummins.

 

[MMeier]

Hmmm, run a cheap t-stat, overheat the engine, cause some sort of damage, and have DC blame the t-stat and void the warranty. I'd rather spend the $30 and get one from Cummins.

I seriously doubt there are any first gens around that are still under warranty...

 

[Ncostello]

I took T-Stat out a little while ago and it looked like what I'd expect as OEM from Cummins. It even looked like the one in the picture in my B-Series Cummins manual. So I figure I might as well get a new Cummins stat. When I opened the Cummins box... I was suprised to see it looks exactly like the one Napa sells. Pretty cheap and wimpy looking compared to my original.



So what gives? How am I supposed to trust genuine Cummins OEM parts when it looks like they are just re-boxed brand X and cost double?



So now what do I do? Install the new Cummins brand x or re-install my original stat that, to my knowledge, didn't have any problems anyhow. I just got the new one since I had it down and drained.

 

[JLEONARD]

How am I supposed to trust genuine Cummins OEM parts when it looks like they are just re-boxed brand X and cost double?

It's likely that the Cummins stat is made to different specs, or tested differently, etc. than the brand X.

Doesn't justify the double price perhaps, but I'd guess it's different.

This is a common practise in the industry.

 

[Bob4x4]

I seriously doubt there are any first gens around that are still under warranty...

I am sure there have been a few reman engines installed that are still covered... ... ... . lol

 

[Greenleaf]

Hmmm, run a cheap t-stat, overheat the engine, cause some sort of damage, and have DC blame the t-stat and void the warranty.

I think what happens is that someone will read a topic and reply and not know what section said topic is located in. It's my opinion and explaination anyway.



On the subject of my second gen thermostat... ... . I use the same one in the 1996-1997 Cummins 12 valve engine. I dunno... ... ... ... I'm just saying... .....

 

[Ncostello]

Seems like the OEM stat and my new Cummins replacement both have little check valves or check balls that let air thru and coolant to fill the head. So no holes needed I think.

 

[JonathanAyers]

The Napa Thermostat might be made by the same manufacture that Cummins

uses. The spec of the thermostat is usually determined by OEM. Napa is a marketer of products, and most of these products are made by OEM suppliers who meet OEM specs.

 

[Shadrach]

1st gen stats have jiggle pins ( for venting air ) and are 53mm in dia. 2nd gen stats have NO jiggle pins ( they use a "bypass " hose and check valve beside the stat housing ) and are 63 mm in dia. Shadrach

 

[Greenleaf]

My 1992 engine has a NAPA thermo. It does not fluctuate (I spell that right?) near as much as the Cummins unit. It does at first, then settles down and flies right.



The Cummins unit never stopped moving except once. I was pulling a trailer up from South FL in the summer and the needle was steady that day.

 

[CToney]

I have found that a Thermostat for a Case IH MX120 works the best. The tractor has a 5. 9l in it. Warm up quick little fluctuation no overheating problems. It is an updated thermostat from what the tractor originally came with. Cheaper than a Cummins T stat. Most Case part #'s are the same as cummins except replace the first 3 with a J and voila Case part # for a cummins.