Engine/Transmission (1994 - 1998) boy that thermostat is a wonderful design

[WDixon27]

i finally got time to install a thermostat in my 12v (didn't have one in it when i got it) and if i hadn't read about it first id of been seriously pi$$ed with that swinging back and forth of the temp gauge, any fix for this wonder of crappy engineering? the new stat came in a cummins box with a august 05 date on sticker

 

[MMeier]

I do believe there was a replacement stat available that eliminated that swinging temp gauge thing. Do a search here and see if anything turns up.

 

[C. Harlan]

I got one from NAPA, and it goes up to just under the 190 mark, then cools back down to about 175-180 once open, and stays there... That just sounds wierd, and maybe its a cheapo stat... Everyone says NAPA T'stats do that, but I have had great luck with mine! Good luck with yours!



-Chris-

 

[WDixon27]

the damn thing even does it at idle, id hoped coming from cummins it wouldn't of sucked, guess they are reboxing crap

 

[Forrest]

Stant use to make a "balanced sleve" thermostat. We used them to keep the temps in check on the gas motors for towing. More expensive, but worked. Don't know if they're still available or where the technology went.

 

[K5IP]

I went through three of them, all from Dodge, before I finally found ont that did not oscillate. In control loop theory, the loop gain is just too high.

'rog

 

[BigPapa]

I just don't understand the big deal. Mine swings too but I have over 200K miles on the original t-stat and it's never over heated, my head is not warped, and my gasket doesn't leak.



I have much more of a problem over the exhaust manifold shrinkage. The bolts on one and six on mine are pulled WAY over. I've heard of them actually breaking the flange off of the heads. Now THAT is a problem!



Scott

 

[PKemp]

BigPapa, I've heard a lot about that bent exh man bolt thing but I am puzzled. I've never seen one. We have 12 dodge CTDs in the service dept that really take a beating. Thier 2500s and 3500s from 1995 to 2004, with from 95k to 416k on the clocks, every one of them is "turned up" and never have we had a bent exhaust manifold bolt, never... . I have several friends that have CTDs from 1994 to 2005 and know of several more around where I live and I have never seen a single bent bolt. This is most puzzling.....

 

[BigPapa]

This is the best I could get it to show up in a picture. You can see it good with a naked eye. The heat transfer pipe is in the way.



Note the red line I added noting 90*. Note also how far over in the hole the bolt is as well as the angle from the red line. The camera was held directly over the valve cover pointing toward the right front wheel.



Scott

 

[WDixon27]

This is the best I could get it to show up in a picture. You can see it good with a naked eye. The heat transfer pipe is in the way.



Note the red line I added noting 90*. Note also how far over in the hole the bolt is as well as the angle from the red line. The camera was held directly over the valve cover pointing toward the right front wheel.



Scott

yea mine is about at that point

 

[bmoeller]

My manifold shrank on me. All but 2 bolts were bent. Solved that problem.



The Cummins t-stats swing the needle as well. Since adding the 370, hasn't been a problem. Guess they make enouggh extra heat to keep it from happening anymore. Mine used to.

 

[MHalloran]

I just don't understand the big deal. Mine swings too but I have over 200K miles on the original t-stat and it's never over heated, my head is not warped, and my gasket doesn't leak.



I have much more of a problem over the exhaust manifold shrinkage. The bolts on one and six on mine are pulled WAY over. I've heard of them actually breaking the flange off of the heads. Now THAT is a problem!



Scott

Big Papa, you should seriously (and soon) consider installing the 3-piece ATS exhaust manifold. I'm sure you don't want to have to buy a new head if this shrinkage continues and cracks it. It happened to someone I know with the same engine. Mine was shrinkin' too so I changed it. Not a hard job & was $$$ well spent.

 

[1dslram]

I have never seen a 12V Cummins with at least 50,000 miles that didn't have shrinkage of the exhaust manifold. This may be due to the warmer weather in So. CA.

Bruce

 

[BigPapa]

W,



Sorry, didn't mean to highjack your thread.



Scott

 

[WDixon27]

W,



Sorry, didn't mean to highjack your thread.



Scott

i don't mind as i may learn something and knowledge is power