And that was some of the greenest coolant I've ever seen. It had 74k miles on it and the original thermostat. It was bright green with absolutely no sludge or sediment in it at all. The lines are all clean to. I looked inside the radiator as best I could and the fins weren't even rusted. I was for sure that it would at least be a little nasty but not at all. I probably could have gone another 74k miles on it. This was the original dodge fluid. The only reason I changed it was because the temp gauge was getting a little warmer than I would like considering the temperature. Don't know why though cause the new one does it also. I got a 190* thermostat from o'reilly's. Do yall think that would be fine or should I go ahead and get a thermostat from the dealer? Thanks for the help yall.

 

If your temps are slightly high and you have not moved your blow-by bottle check between the radiator and the intercooler for oil and dirt build-up. If that is clean check the operation of your fan clutch to make sure that is working correctly.

 

I too was having problems with temperature fluctuations on my truck. Went to the dealer to ask if a new thermostat would solve the problem and he said it would not. This is what the dealer explained to me:
Since the first 2nd gen rolled on to the road, the problem has been there. The reason is the large cooling capacity of these trucks and the iron engine block. The block sucks up a lot of the heat and when the thermostat opens the flow of the cold fluid cools it off again, and at the same time the warm coolant enters the radiator, obviously. After some time, the thermostat opens again but the fluid in the radiator has already cooled below what the engine temp should be. It keeps cycling like this in cold weather unless the truck is driven hard enough to warm the fluid fast enough inside the block, so as to keep the fluid inside the radiator from cooling too much.

hope this makes sense, Pat

ps-maybe try the grill covers in order to keep the radiator from cooling the coolant to much?

 

BigB, how exactly did you flush the cooling system? I've been thinking about getting one of those Prestone flush kits that you splice into a heater hose.....but.....
I need to do this soon....pushing 50k miles (even though your's was clean) I've got a 3k+ mile trip to SD coming up in April with the camper and towing a trailer. I ditched my breather bottle a couple months ago due to oil/dirt buildup on the radiator, so during the coolant change I need to pull the rad to clean it.
btw, I have similar temp fluctuations too....usually with a load in the truck it'll go about a gauge needles thickness past 190*, then drop down to normal and will only go back up if I'm pulling a good grade.
I'd keep your new thermostat in the truck...imo.

 

Ram2940, I moved my breather bottle a while ago but I should still clean it anyways.

pgilles, the reason I changed it out is before this winter, the truck would sit either a needles width above or below 190. Usually below for anything less than 100* weather sitting in traffic. It's been that way for the past 3 or 4 years. This winter for some reason, it suddenly started going up to 200-205 and then back to 180 or so and then back up. I figured that can't be right. So I changed it.

Moose10, I took off the upper and lower radiator hoses and thermostat housing. I stuck a water hose in the thermostat opening and let it run until the water coming out of the lower radiator hose was clean(the hose is still connected to the block) and then I took the hose and put it in the hole where the upper radiator hose plugs into the radiator and waited till the water came out clear.

 

Hmmmm that sounds like an easier way than spending valuable BOMB'ing $$ on the flush kit.
So did you use distilled water on the refill? also, how many gallons were you able to fit back in the system?
Thanks dude !

 

I thought I read on this forum somewhere about troubles with other than Cummins t-stats. Something like the NAPA brand were junk and the Cummins ones were actually the same price or so. I am trying to access the data in the ol' hair-covered-computer, but will probably try the search later tonight.

 

Moose10, I'm gonna get flamed for this, but I used regular tap water. I put some stuff in there to neutralize the minerals. I put in 3 gallons of coolant and I have no idea how much water.

zulusafari, I didn't feel right about the o'reilly thermostat so I went and bought one from dodge. $42. The o'reilly one was $30. They guy didn't know what temp it was but he said it should be a 190*. It looks totally different than the one I pulled out but he said the part number has been superceeded several times and this was the current part number for the day.

 

BigBlue,

Did you just run the water onto the ground when you were flushing the block and the radiator? Isn't this stuff toxic? I'm not a "greeny" by any stretch of the imagination but I try to be as responsible as possible.

Along these same lines, does anyone use the Sierra brand coolant? Pro's and con's of this stuff? I see it on the shelf everytime I buy coolant but I've always gone with Prestone (name brand, quality stuff).

 

Yes Idaho I did let it run on the ground but I made sure that the water kept running at all times to help dilute the stuff as much as possible. I used the o'reillys brand coolant.

 

I do it that way too because I honestly have no idea what to do with gallons of used coolant, do I throw it in the trash or do I take it somewhere?

Dan

 

I totally agree. It's easy to amass a lot of old coolant quickly, especially when flushing. You could have yourself 50+ gallons in no time at all. "They" say you're supposed to dispose of it properly but I've also heard that some communities' water treatment plants address the issue of incoming coolant. I really have no idea if that's true or not - just something I've heard/read.

 

PLEASE take your old coolant back to the store you got the new stuff from.. Most major parts dealers, ie *mart and Crappie tire will dispose of the stuff for no charge..

If you live in the city, and wash it down the storm sewer it dose not go through the waste treatment facillity, it goes straight into the lake or river wich is close by. And Most of the time it is the same body of water that the municipality collects the drinking water from.

If you live in the country, you probobly know better, cause your water comes out of the ground from a well beside your driveway..

Its not that big of a deal to get a couple of five gallon pails, free behind your local donut shop, and collect the old fluid, and dispose of it properlly. Thats why we got trucks, to haul stuff. I use it as an exuse to get out of the house and drive my diesel..


Thanks for looking out for our kids drinking water.


Just wondering, you dont wash your used oil down the sewer, do you??

 

You need to add some coolant conditioner to the antifreeze. Go to the parts store and get some. I use Wix or Fleet gard. The instructions come with it for initial charge and make sure you add some once a year to keep it neutral. This will keep your cooling system in good shape for most of the life of the truck.

 

Couple things here: First, only use the Cummins/Mopar themostat, 2nd, the flushing method described above works great, just remember to do the heater core as well. I then use air to get the "City water" out of the block, then I use Pre-mixed anti-freeze from the Cummins shop, Fleetguard works great. I have a huge drainpan to catch all this stuff. And in Idaho the local landfill takes waste oil/anti-freeze for free. If you get caught letting it go in the drain you can get in "hot water" real quick!

Tom