12VRattler

I bought a 96 ram 2500 4x4 a week ago and have been driving it quite a bit. Friday as I was heading into work I noticed that the temp gage was a little over 140 and would go almost over to the 230, then slowly creep back down to the 140 mark. I was going a little over 70 down the interstate and this continued until I got to operating temp then it seemed to slowly quit doing it. The other day I had also noticed as I was idling around my couple of acres that it was between the 190 to 230 mark, I thought that was pretty weird being it has only been about 50 here and it was under no load. Is there any common problems relating to this? I searched but couldn't find anything about this in particular. It is full of antifreeze, but I have not checked the freezing point of it yet to find out if it needs changed or not.
Any suggestions?

JohnBer

sounds like it might be getting a little warm on top there but the big fluctuation
is quite normal because of where the sender is mounted on the engine and the large radiator, its just the thermostat cycling the coolant. i put a 180 in mine and it just runs up and stays there. think stock is 190. Get yourself a cummins thermostat,little more money, but, it will give you years of trouble free service.

justme-

Sounds like something is up...it's not normal to hit 230 on a stock 96 truck. Maybe with a 0 plate, but definitely not stock. The stat opens about 195 in mine and draws it right down to 140 ish... the center line in the gage is where it should open and draw down.
I only hit 230 when the t-stat went bad in mine... even plowing snow all winter, it only breaks 200 once a season. When my stat went it had higher temps, then it stuck closed and started to overheat me, next it stuck open and wouldn't build any heat.

I'd flush the coolent and change the t-stat. Agreed buy the cummins stat, and if you want to keep the gage acting the same tell them you want the original stat not the updated one. (the update opens way early and acts like a gas engine stat keeping it at a lower temp all the time)

12VRattler

Is there a down side to keeping it at a lower temp all the time? I know gas engine wise it helps in the power department but hurts in the economy the majority of the time. I am just to a vehicle warming up to around 180-190 and staying there. The way this was fluxating back and forth fairly quickly, I was wondering if maybe there was a common sender problem of something of that sort.

infidel

The swing in temperatures mostly has to do with the location of the sender on pre '98 engines.
The swing is normal and of no concern.
Going up to 230 is a problem though, either you need a new t-stat or your gauge is reading incorrectly.

96_12V

As your owners' manual will tell you, it's normal for these to run either stable (such as my 96 is) between 140 & 190 or cycling (as my '95 did) between those points. The only time you should ever see above 190 is when towing a quite heavy load, and even then it should not go to 230. You cannot think of these engines like a gas engine, fuel mileage isn't going to diminish running cool, it's a traditional diesel engine, therefore designed to operate with ver little waste heat.

SoTexRattler

Time for a new 'stat...
Soon.

Mine used to cycle quickly between 190 and 160 on the hwy. Purely normal...
Eventually it would get to where it would spike upwards of 210+ on initial warmup before it would drop to normal range and cycle slowly.
One day it just stuck and got HOT!
FYI, 'stats from Cummins dealers are ~half the cost of the 'stat from Dodge dealers. Dodge sells a Cummins box with a Dodge parts label stuck over the big "C" part label.