Engine/Transmission (1994 - 1998) Bad gauge or stuck thermostat?

[mdivincentis]

I picked up my truck yesterday after having the entire thing Line-X'd and it would not warm up. The gauge would stay below the operating range until I began to climb a long steep grade. Now that I am back home and am not making long trips, it will not warm up at all. the highest I have gotten the temp gauge is to just below the start of the operating range. Is it a bad sender/gauge, thermostat stuck open, or something else?



The truck is a 98 12v, 119000 mi.



Thank you,

Matt

 

[illflem]

My bet it's the stat. There is a rubber gasket around the outer edge of the stat that is prone to coming off and getting stuck in the open stat keeping it from closing all the way. You can replace the stat or do like I've done and just toss the rubber ring, seems to work just fine without it.

 

[Andy Redmond]

3934373/3834373 Cummins #'s///



Dodge #'s

4797255 Thermostat gaskets

4761291 Thermostat gaskets

4644269 radiator drain cock (you need an o-ring too, but I don't have the part # handy).



18 ft. lbs on the t-stat housing bolts.





I confer with Bill, stuck t-stat, good luck.

 

[SRadke]

I'll third the opinion. Not an expensive item or difficult to fix.

-Scott

 

[SRehberg]

My '96 just started doing exactly the samething, so I bought the Cummins parts for the thermostat replace. My numbers were different than above, so it is suggested you take your engine number to Cummins. I have a question to anyone with experince; I have read past posts regarding the use of long-life antifreeze. There seems to be a consensus that the use is determental to the seals/headgasket. I know a lot of new cars come stock with long life antifreeze so I'm confused. My other '96 I installed the long life two years ago, and was planning on changing my recent purchased '96 to the same. Now I'm cautious that it maybe a mistake. Any ideas? The pluses I read (besides the extended drain intervals) was the lack of abrasive particals which was kinder on the water pump bearing/seal, and abrasion on the radiator itself. Sounded good, but if the gaskets crawl or deterioate, then it is not worth it.

 

[illflem]

When extended life coolants first came out some weren't compatible with certain rubbers used in some vehicles. But corporate America being the savvy guys they are realized they were losing a large chunk of the market and formulations have changed so that extended lifes will work in any rig now.



Did you know? all the anti-freeze in the US was made in just two plants until a few years ago when one burned down. Now it's all made at one plant.

 

[Boomer II]

Same thing happened to me that illflem mentioned in his first post, easy fix.

 

[PUMPERDUDE]

Mine started running way cool a couple years ago. When I pulled the T-stat there was a big piece of metal in it. Looked like a twisted piece of casting. Funny it didnt spit that up before it had rolled 160k miles or so

 

[Deezul1]

illflem is right on as usual. Mine did the same as yours and the stat was exactly like illflems.

 

[mdivincentis]

Thanks for the replys, guys



Now...

The truck seems to have cured itself before I had a chance to fix it. Everything seems normal now. Anything I should be worried about?



TIA,

Matt

 

[illflem]

Don't know what good it would do to worry about it because there's really nothing you can do but if it was the gasket holding the stat open I'd have to wonder where it went. I've have no idea where it might get stuck but it for sure wouldn't make it past the radiator core.