bryanburns

Have 2004, 2500 6sp, ho, temp never went abv 190, running empty or towing, now stays at 200 all the time, dealers claims this is normal, claims temp shld run between 190 and 207, everyone sez that temp shld never go over 190 towing or otherwise, please advise

bulabula

I don't think you have an "overheating" problem either.

At normal operating temps, my temp guage doesn't move all that much but it does move. Is 200 the center point of the guage? (I can't remember and truck isn't nearby), but my temp needle runs vertical or just slightly to the left of vertical most of the time; but it does sometime move slightly to the right - loaded or unloaded.

Delectric

I have two 03's and they both run between 190 and 205. Whoever said shouldn't go over 190 is wrong. I wouldn't worry about it, you have got a long way to go before it over heats so if its at 200 its not a problem. Don't listen to everything you hear, check your manual or the Cummins site etc. You can't always believe what the dealer says either. This I can tell you though is that there are lots of "experts" out there that will give you advice, but be careful. You need to do some research of your own because it may save you some grief down the road. I am no "expert" either but I do know about the temps because I was concerned because one of mine ran hotter than the other, until it started getting more miles on it, then the temps went down. There are many knowledgeable people here, but by the same token..................

bryanburns

thanks for the help.my truck allways ran at 190 untill it reached 28.000miles then it started climbing up to 200 or just a hair below . the truck runs better now than it ever did before .just turned 30.000mi

rmb93243

The fans don't even kick on in my rig until its around 205° or so. Nothing to wory about.

Dodgezilla

If you are really concerned you could install a Cummins 180 stat like I did. My temps stay at 180 and may rise to 190-200 if towing on a 100 degree day...

rmb93243

How well does your heater work now (I don't mean now, during summer ). I did that to my Cheby and could never get the defroster warm enough.

Planetcat

Mine has run at about 199-200* since the day I got it. Unloaded, towing boat, hot weather (100*), cold weather, it's all the same. I wouldn't go messing with the T-stat unless you're really overheating (i.e. boiling over) and you think it's stuck closed. Opinions differ on the t-stat subject, but the engine is designed to run at the factory thermostat temp, not lower.

Dodgezilla

My defroster works fine. I had no problems at all last winter and it was really cold here for a couple of weeks straight.
All engines are designed to run at the factory t-stat temp but that's mostly for emissions purposes and not performance. I do know that when my truck was on the dyno, the operator said that the trucks make more power when they are warmer. My truck pulled harder and harder as it warmed up.
I'll keep my 180 stat. I like a coooool engine............

JamesP

Dodgezilla, Does Cummins recommend the 180 for better performance in their diesels or do they just offer it?

Cooler temps would make the oil last a little longer too I would think....

nonford

Mine sits @ 190 most of the time. On a few ocassions right on 200 or just a tad over, but comes down. I think your fine.

Dodgezilla

I don't think Cummins recommends it, but they sell it. I have never owned a vehicle that I did not put a cooler t-stat in. It's just like a better flowing air filter. Those are the first things I do when I buy a new vehicle. I have heard that it makes the oil sludge up if the engine doesn't run hot enough but I've never had that problem.

Maybe I'm nuts. Who knows....

nickleinonen

diesel engines like to run warm/hot... i don't see any need to go lower than a 190° t-stat... my truck temp gauge sits at the vertical mark mark or on a hot day with the a/c going, maybe 1/8" to the right past the vertical mark