Chrysler 300C & SRT8 Forums banner
1 - 12 of 12 Posts

·
Registered
Joined
·
464 Posts
Discussion Starter · #6 ·
Thanks guys. Guess I need to check my settings again. Got up to 200 on the highway the other day.
 

·
Registered
Joined
·
466 Posts
Im usually around 200-210 on the highway. We also live in the south where its hot and humid as hell out. I just installed 180 Tstat and adjusted the fan settings. So ill see where i stand in a few days of driving.
 

·
Registered
Joined
·
6 Posts
I'm a little confused with the post. First, the HHP instructions are for the 180 degree thermostat. Are there different recommendations for the 196 degree thermo? Also, why would a thermostat that opens at a cooler temp cause the cooling fan motors to run constantly if using stock programming (as stated in the HHP instructions)? I would think the opposite would be the case. If the engine is running cooler, the cooling fan motors with the stock programming would run less, not more, right? And what is the benefit of a cooler thermostat if the fan settings are set to come on at higher temps? That sounds like a zig-zag - the zig of the cooler thermostat is negated by the zag of cooling fans that don't come on until the engine is warmer. What am I missing?
 

·
Registered
Joined
·
156 Posts
I'm a little confused with the post. First, the HHP instructions are for the 180 degree thermostat. Are there different recommendations for the 196 degree thermo? Also, why would a thermostat that opens at a cooler temp cause the cooling fan motors to run constantly if using stock programming (as stated in the HHP instructions)? I would think the opposite would be the case. If the engine is running cooler, the cooling fan motors with the stock programming would run less, not more, right? And what is the benefit of a cooler thermostat if the fan settings are set to come on at higher temps? That sounds like a zig-zag - the zig of the cooler thermostat is negated by the zag of cooling fans that don't come on until the engine is warmer. What am I missing?
I've often wondered the same thing. Everyone is like your fans will run all the time but HOW if your thermostat is opening at a lower temp?

The only thing I can think of that is bad is your temperature will fluctuate alot more in traffic because without fans moving air your temps will continue to climb even with a 180* thermostat. Once your fans come on at the stock settings it'll regulate the temp around those setting. Once traffic clears and you're really moving the temp will creep back down to the 180* thermo setting.
This can mean your temps will have a 20-30* temp swing driving in traffic which could put stress on the motor.
 

·
Administrator
Joined
·
13,064 Posts
A thermostat that opens at 180 degrees does not keep the coolant temps from rising. Depending on airflow across the radiator, ambient temperature and humidity the coolant temp will still rise, hence the fan setting options on some programmers.

Consider an 80 degree day and you are traveling slowly, stuck in traffic. There's not enough airflow going through the grille or passing under the car to keep the coolant temp from rising. The fans kick in to provide what is missing, i.e., airflow.

Fan temp settings are something that can be tweaked given the temps you experience + the spec on your thermostat. For instance it makes no sense to set a fan to come on at 191 deg F if the Tstat doesn't open until 196 deg F. The coolant isn't being circulated through the radiator to the engine so why cool it?

However, look at the other scenario.

You have a 196 deg F Tstat, you live in a hot climate and unless you are running at freeway speeds all the time, your coolant temps are gonna shoot up past 210, possibly to 220 or beyond. I believe the stock LS fan temp setting is 217 and the HS fan somewhere around 222 to 223. Having a fan set at 196 won't do any good as your fan will always be running. But...if it's set at, say, 205 LS and 210 HS, then you can be sure the coolant will stay a bit cooler and the fans won't run ALL the time but they will run until you get more airflow moving through the radiator.
 

·
Registered
Joined
·
464 Posts
Discussion Starter · #11 ·
Just checked my settings again n they are 191/199 all. Went for a short drive n already at 199. It never gets above 202 but with those settings n a 180tstat should've been lower?? It's currently 90ish degrees outside.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
466 Posts
I drove 117 miles yesterday. I was driving it pretty hard on back roads which had a lot twists to it, so i was having some fun. The hottest it got was 212. I think the lowest I've seen it so far was around 196 and it was over 90. After the fan settings i noticed it wasn't as loud as before with stock settings. I set mine to HHP recommended settings HS 194, LS 189 and MD 192.
 
1 - 12 of 12 Posts
Top