Engine/Transmission (1998.5 - 2002) ? on T-Stat for 01 Truck

[MCrossley]

Hi everyone well it was 106 yesterday and today (weather chanel said 89 yeah right) anyhow truck has 103k on it and I noticed today that I am sitting right on or a needle hair above the center mark on the coolant. So just curious if everyone thinks the 180 is better than the 190 or anyone think there is truly that much difference. The truck is a daily driver that on occasion pulls in upwards of 23k GCW and seems like more and more hot days each summer so what does everyone think? Also does Dodge carry the 180 or just the 190? One other thing, the A/c never gets shut off during the summer if that matters any.

 

[JBlock]

Mileage Up

Some say the mileage goes up, Dodge switch out to the 190 for cold idle emissions or something, the earlier truck all use 180. Get it at the Cummings shop. When I changed mine, in move the needle from about 1/16 inch passt mid point to a 1/6 inch below. It a hard pull either of them run up to 210.



JB

 

[willyslover]

Mike . . I did the 180 about 6/8 months ago and am glad I did it... . helps keep temps in check better IMHO [especially for extra powered motors]

 

[ToolManTimTaylor]

Re: Mileage Up

Originally posted by JBlock

Cummings shop. .



JB

AAAAhhhhhhhhhhh! Haaalllp he is a spy!



I gotta hop on the bandwaggon to get a 180. God I think I'll do everything else to the truck ..... but a simple thermostat #ad

 

[MCrossley]

Thanks for the replies guys... I was over at the dealer today and the mechanic was saying the 190 was better for towing but I tend to think the 180 is going to keep things a bit cooler earlier on; I mean if it is going to go past 200 then it is going to go past 200...

 

[TowPro]

The guy I talked to at the Cummins shop said "no way in heck I would put a 190 in it" But Dodge does.



I plan on buying one next time I am in Harrisburg ). That should be a fun trip, harbor freight an Cummins in the same day!

 

[BILLUA]

Thermo

I replaced my 190 with a 180 in march. Initial obeservation was no change at all. Now that summer is here and I am towing about 6 thousand to the lake, it heats up real fast to 180 or so and then the fan comes on. We all know what that is equivalent too... About a 50 mile and hour headwind! It seems to me that the fan is running alot more with the 180 degree thermostat than it did with the 190. This oberservation is mine only and please keep in mind that I live in Las Vegas and the outside air temps that I am making these observations at are in the 100 degree plus range. If it does not get as hot where you live, or if you are not towing too heavy or have the box set on 2 or below most of the time, I believe that the 180 is probably ok...



Just my . 03C





B²

 

[jrandol]

I was about to post a similar thread needing Questions answered but this seems to be a good place to start. My 02' when 1st ran for the day (warmed up of course) does funny stuff. I take off after a brief warmup now that it is summer and I get out on the open road to let it build heat. The gauge comes up and keeps going past the 1/2 mark and stops at about 210 I guess. Sits there for what seems like forever as I sweat about it and then finally drops off. After that, no matter what I do just shy of pulling a freight train it will not go past 190. This initial run and hold up to 210 has me wondering what the deal is. Anyone else experience the same or have a solution?

 

[ToolManTimTaylor]

yeh mine does the same first needle cycle goes high the "Normalizes" juust shy of straight up.

 

[WadePatton]

I'm running a 180 and my needle will almost hit 190 before it opens up then drops back to 180. Cummins says 180, peewee on DC- I'm running a 180.



The fan. Someday, after all my go fast and customize thingies I'll get a Horton fan. Nothing like washing and waxing and then a few miles later--doing a restart on a dusty surface.



Then if I get it to 190, I'm pushing it real hard. Usually the EGT's keep me from doing that.



But I rarely tow heavy. Mostly just HFA.

 

[truckstom]

The Cummins part # for the 180 t-stat is... . 3954194... . happy coolin'

 

[RichB59]

Towing in Vegas!!

I towed my travel trl(4000lbs) into Vegas yesterday temps were 108 in town. I have the 180 installed. The gauge goes to straight up when working uphill. The cooling fan engages and it drops back to the 180 mark. I think the cooling fan is working more often than with the 190. Why I don't know???? I guess the important thing is it doesn't overheat. Trans temps were at about 150 with probe in the pan not to bad considering the heat outside and it only comes up when working on a long uphill then drops back. Oil press holds good. I always watch oilpress in the heat it's a good indicator of true engine temps it will start to drop if you get to hot. The trip we took was 2500 miles without a hitch love that cummins!!!



RichB

 

[MCrossley]

I have to agree that if Cummins is saying 180 then 180 sounds good plus all you guys running them seem happy. Also though for those of you who say your fan is coming on more often I want to let you know when the outside temp is over 90F my fan will almost run all the time in town and on and off on the freeway so it might just be that you are running in the higher temps and therfore think the fan is coming on more often. I will have to get one of my north bay buddies to run to Cummins and pick one up I never go out that way...

 

[RustyJC]

The reason the fan is running more often with the 180* thermostat is that more heat is being rejected from the coolant to the radiator than with the 190* thermostat. The 180* thermostat is open more often; thus, the air temps coming off the radiator trigger the fan clutch more often.



Where is this heat coming from? Ultimately, combustion of the diesel fuel. By going to the 180* thermostat, the heat balance of the engine has been changed. If the heat is being rejected to the cooling system, it isn't available in the combustion chamber to make cylinder pressure that makes BHP or in the exhaust manifold to drive the turbo.



If the truck isn't overheating with a 190* thermostat (and mine doesn't, even towing at 21,180 GCW in Texas summers), minimizing heat rejection to the cooling system means more heat is available within the engine to convert to useful work. Thermodynamics 101.



Rusty

 

[BILLUA]

Thermo 101

Rusty, thanks for putting into english why the fan runs more with the 180 thermo vice 190. I am going to put the 190 back in today as towing with the 180 in this Vegas heat brings my mileage down to 11-12 while towiing with the fan on most of the time.





I believe someone threw in something about trans temps earlier,

While towing 6k as long as I am in lockup, 3rd lockup or o/d lockup up, my temps never get above 180 degress even if it is 115 out. Now, if I am in stop and go traffic or have to sit at traffic lights, it can get up to 215 in no time. These readings are taken in the trans cooling line.

Two things that really help to keep trans temps from climbing: 1) DTT smart controller allowing 3rd gear lockup, you'll love the lockup for deceleration purposes too!, 2) putting the truck in neutral if sitting in traffic at a stop light...





Cheers, B²

 

[hammersley]

OK guys I have a post running on the overheating

AND my fanclutch. I can't seem to tell if it's comming on? How can I check this thing?? Other's have said that you can hear them - well their ears must be better than mine. I even took it to the dealer and they couldn't tell. If you look at the fan, she is always turning - but I don't hear the rush like you hear from rice-burners when their fans come on. But then they don't have a fan clutch, they usually only have the electric fans... ... The dealer told me to block off the radiator when it's hot and see if she kicks on... . If the fan clutch is bad - where and how do I fix that?????

 

[RustyJC]

If the fan clutch is working, I promise you'll know it when the fan fully engages (it will turn all the time due to fluid drag in the clutch). It sounds like a Rolls-Royce RB. 211 jet engine just lit off under the hood. With a 190 deg thermostat, I run about a needle width below 190 when empty and a needle width above 190 when towing (21,180 GCW - 21,500 GCWR). The fan clutch normally will kick in when towing up a long grade - the coolant temp will drop back to about 180-185 and the clutch will drop out.



If the fan clutch isn't engaging, the clutch may be bad. However, if the engine coolant thermostat isn't opening, there won't be enough heat rejected to the radiator to trigger the fan clutch, so it could be a thermostat problem. Also, if the air side of the radiator is plugged, airflow and heat rejection are negatively affected.



I love the dealer's suggestion previously posted to check the fan clutch out by blocking the radiator with cardboard and seeing if it comes on. Let's see, the fan clutch is actuated by hot air coming off the radiator. Now, if I block all the airflow, what's going to actuate the clutch? Sigh... .



Rusty

 

[Pit Bull]

Originally posted by RustyJC

The reason the fan is running more often with the 180* thermostat is that more heat is being rejected from the coolant to the radiator than with the 190* thermostat. The 180* thermostat is open more often; thus, the air temps coming off the radiator trigger the fan clutch more often.



Where is this heat coming from? Ultimately, combustion of the diesel fuel. By going to the 180* thermostat, the heat balance of the engine has been changed. If the heat is being rejected to the cooling system, it isn't available in the combustion chamber to make cylinder pressure that makes BHP or in the exhaust manifold to drive the turbo.



If the truck isn't overheating with a 190* thermostat (and mine doesn't, even towing at 21,180 GCW in Texas summers), minimizing heat rejection to the cooling system means more heat is available within the engine to convert to useful work. Thermodynamics 101.



Rusty

Rusty good info. So DC spent millions of dollars engineering this truck with the CTD engine and they got it right on the thermostat. That is weird that a bunch of guys can't figure out a better way. :-laf

 

[WWalters]

I guess that I need an additional lesson in Thermodynamics 101.

I thought that when the engine is under full load and the thermostat is fully opened, the maximum amount of coolant would be sent to the radiator for cooling and a small amount of coolant would still be sent through the bypass tube. It would seem to me that it wouldn't matter if the truck had a 180 or 190 degree thermostat. In this situation, both would be fully opened and the fan would be operating the same in either case.

 

[RustyJC]

If both the 180 and 190 degree thermostats are fully open and the coolant temperature of both engines is the same, then the heat loss is indeed the same.



My point is that, within the control range of the thermostats, the 180 will reject more heat through the cooling system than the 190. It has to in order to keep the coolant 10 degrees cooler under the same conditions, right? This additional heat that's lost to the atmosphere came from the fuel, so it cannot contribute to the engine's thermal efficiency.



Rusty