Engine/Transmission (1998.5 - 2002) 180C vs 190C thermostat

[Lockard]

What are the pros and cons to replacing the surrent stock 190C thermostat with a 180. WIht the onset of 95+degree weather here in Raleigh I noticed that the truck is going to 200-210 on the highway and the fan clutch in kicking in (the jet engine noise). Thought the 180 might help this issue. Besides the 180 is about half the cost of the 190. Thoughts?

 

[John - K5AWO]

You have cooling issues to deal with. It is not the thermostat. At the present time of writing this, the local temperature is +112 and I am having no problems with cooling on my CTD. The temperature guage sticks to 190-195 all the time after the iniatial warm up process. The only time I have ever seen the guage climb above 195 is at an idle when the temps are greater than 112, A/C on. I sweat too!



I have never even heard the fan clutch pull in tight enough to make any audible noise yet.



My thermostat is a 190*F per factory specs. You wrote 180C and 190C, I surely hope that is not the case as your pistons will have melted by now.



The CTD is a heat engine and it needs to be at the right temperature to properly combust all of the fuel. Lowering the thermostat temperature setting is not going to resolve your problems.



Have your radiator rodded out and fresh antifreeze installed. Make sure that all of the fins are not blocked by bugs and dirt. On my truck, I found that some line wash boy had used a high pressure sprayer up real close and flattened about 30% of the fins on my radiator/a-c condensor/trans cooler package. It was done before I bought the truck used at six years of age. Even at that, the only cooling problem it evidenced was lack of a/c cold air below 1000 rpm. When rolling above 10 mph everything was just fine. I used a thin steak knife to carefully lift each fin up one by one to resolve the issue. Painstakingly slow work, but necessary.



Goto Profiles and enter all of the pertinent information about your truck so that any TDR member can assist you properly. It is hard to make helpful judgemental decisions with a lack of info. Read other's Signature lines to give you an idea of the things that we normally post in the Signature/Truck Description fields. Year model, series, etc...



Hopefully what has been presented will be of some help so far.



Do have a nice day...



John

 

[cjohnson]

I wouldn't hesitate to replace the thermostat with the 180. My understanding is that only Dodge uses the 190 in their application, all other applications for the 5. 9 use the 180. I couldn't even get a 190 from Cummins. While I agree with the previous post that you should make sure your entire cooling sytem is in order, I completely disagree with him saying it is NOT your thermostat. It could very well be what is contributing to your problem. When I did my first coolant change, I was experiencing higher running temps as well. At the time of coolant change, I didn't have a replacement thermostat to put in. Long story short, I still had the same high temp problems as before. As soon as I replaced the thermostat ( I used a 180), problem solved. It has been pretty well noted that the thermostats in these motors have a limited life. I wouldn't run more than 30-40 thousand miles on one.

Take that for what its worth.



Craig

 

[cumminspwr01]

The only problem with running a 180* thermostat around here is that in the winter time it doesn't let the heater warm up enough to keep the little lady happy. Even with the blower turned all the way up it doesn't get very warm. So I reinstall the 190 in the fall.

 

[jkern]

depends on what year your truck is... my 99 has 180* T-stat in from factory. i think in 2000 or 2001 they went to 190* for a little more heat.

 

[FourBarR]

just changed the stat in my 98. 5. its the original 180 degs. truck has 314745 km. or about 190000k.

 

[JR2]

The only difference I noticed when I went from 190 to 180 was that my temp gauge read a little lower all the time. Winter heat (in Alaska) is not a problem, its actually better now because the truck used to be able to cook me out of the cab, now its just right. Do a search, there where quite a few discussions about this.

 

[Lockard]

Thanks for the info. I changed out the coolant to the Fleetguard pre-mix about 8000 miles ago. The highest the temperature got to approx 200-205 turing 2600 RPM's in 85F with the AC on. Maybe that's normal, but the fan kicking in got me worried. With the drive home temperature now at 95-98 the fan kicks in under the same circumstances described above. I bought the truck used with 70K on it and have out another 60K on it so maybe it's just time for a thermostat change.

 

[John - K5AWO]

Just saw your post. Your anti-freeze is okay. just change the stat.

 

[Rman]

Another point I'd like to stress is cleaning the radiator out. Removing the intercooler and cleaning both the front side of the radiator and the intercooler and the ac radiator is vital. Mine gets clogged with tons of bugs an causes some serious blockage of air flow.

 

[kacee3759]

I have a 99 that had a factory 190 stat. I had temp problems when pulling any load at all up a hill. It would get right up to the red line with the rpm's up. I was told by the local Dodge dealer that was normal. I tried several things including replacing the coolant with Fleetgaurd premix and a new air filter and 4" exhaust to help the engine breath better. None of these helped. I changed to a 180 stat. and all my problems went away. Even when pulling a heavy load up a hill in hot weather the temp never rises to more than 190 maybe 195. Could have been a bad therm. stat. from the factory, I don't know but I'm sold on the 180.

 

[DGFoster]

Originally posted by Rman

Another point I'd like to stress is cleaning the radiator out. Removing the intercooler and cleaning both the front side of the radiator and the intercooler and the ac radiator is vital. Mine gets clogged with tons of bugs an causes some serious blockage of air flow.

That is the ticket,mine was just plain packet with bugs and oil from the blowby bottle and the only way to get it clean is to take it out.