Chrysler 300C & SRT8 Forums banner

1 - 20 of 36 Posts

·
Registered
Joined
·
204 Posts
Discussion Starter #1
I've searched and found tons of info on the Hemi and SRT8 thermo upgrade, but I can't seem to find any info on the 3.5 V6 or the 2.7 for that matter. I've looked for the thermostat and it doesn't seem to be easily accessable. I'm thinking it might be more work than it's worth if it's under the intake manifold. Anybody gone through the work to do this on the V6?

Before I get made fun of, my only reason for doing it is that I live in AZ and under hood temps are ridiculous out here. It doesn't get very cold here, but it gets extremely hot so a ~170 thermostat along with the Predator should allow me to keep the temps under control.
 

·
Registered
Joined
·
1,129 Posts
sure bro, do it. it cant make it worse.

however, i used the 185 tsat so that i wouldnt throw any codes from the engine running too cold. should be above 180

give you a lil more power and maybe better fuel economy.
 

·
Registered
Joined
·
204 Posts
Discussion Starter #3
Any idea where it's at on the 3.5 and how easy it is to change? It's looking like this is a bit more involved than the typical thermo swap.
 

·
Registered
Joined
·
1,129 Posts
im not sure bro. havent looked in the bay of a 3.5

is there a pic of it on the forums here somewhere?

take a pic and post it. we can tell ya hopefully then.
 

·
Registered
Joined
·
204 Posts
Discussion Starter #5
I'm not sure of any pics on here. I'll snap a few pics tomorrow(I'm in bed). :24:

The upper radiator hose leads to the intake, but it doesn't look like that's where the thermostat is actually located like it is in most other applications, including the C and SRT8.
 

·
Registered
Joined
·
204 Posts
Discussion Starter #6
Hmmm...still no luck finding this damn thing. I can't seem to find any info on the web about where it's located either.
 

·
Registered
Joined
·
1,129 Posts
i looked as well,

tomorrow ill visit one of my chrysler dealers and look under the hood of one.
 

·
Registered
Joined
·
255 Posts
Juat curious, but is your engine even running hot? I would think the engineers took hot weather into account when designing the car.


I live in MN. My temp gauge stays about the needles width under the halfway point no matter what. -20 degree weather or 100 degree weather. If your needle never goes past halfway I dont think you need to bother with this.
 

·
Registered
Joined
·
204 Posts
Discussion Starter #9
Juat curious, but is your engine even running hot? I would think the engineers took hot weather into account when designing the car.


I live in MN. My temp gauge stays about the needles width under the halfway point no matter what. -20 degree weather or 100 degree weather. If your needle never goes past halfway I dont think you need to bother with this.

lol, tell that to the hundreds of thousands of people who have done this over the years. If your tranny shifts perfectly fine, why upgrade with a shift kit? If your motor runs just fine, why put a set of headers on it? If your rims are just fine, why put 20"+ rims on it? :smashfrea
 

·
Registered
Joined
·
1,305 Posts
The reason it is done is to keep the motor cooler then the stock temp which is either 190 or 210. Cooler temps in the engine keep everything else cooler. Its a cheap and easy thing to do.
 

·
Premium Member
Joined
·
1,739 Posts
The reason people put in a cooler thermostat in the 5.7 is that there appears to be some power loss due to "heat soak" when the engine reaches the stock temperature of over 200 degrees. Does the 3.5 benefit power wise from running at a lower temperature the same way the 5.7 does. If there is no power increase in going to a cooler thermostat, why bother?
 

·
Registered
Joined
·
204 Posts
Discussion Starter #12
Apparently some of you guys missed this part in the first post:


Before I get made fun of, my only reason for doing it is that I live in AZ and under hood temps are ridiculous out here. It doesn't get very cold here, but it gets extremely hot so a ~170 thermostat along with the Predator should allow me to keep the temps under control.

When it's ~125* outside and I'm driving in stop and go traffic with the A/C on HI, I'm sure my cooling system is working it's ass off to keep the motor at a reasonable temperature.

I'd rather not have to read another "Why bother" or "What's the point" post because if you look at half the s**t on this site that people do to their cars you could say the same thing. Why do ANYTHING to your car? Why mod it at all? Why not just keep it stock? Why even drive? :twak: :soapbox:
 

·
Premium Member
Joined
·
1,739 Posts
Apparently some of you guys missed this part in the first post:

When it's ~125* outside and I'm driving in stop and go traffic with the A/C on HI, I'm sure my cooling system is working it's ass off to keep the motor at a reasonable temperature.

I'd rather not have to read another "Why bother" or "What's the point" post because if you look at half the s**t on this site that people do to their cars you could say the same thing. Why do ANYTHING to your car? Why mod it at all? Why not just keep it stock? Why even drive? :twak: :soapbox:
The point is that you learn from the experience and knowledge of others. There is no point in doing a mod that does nothing. We are trying to determine if a cooler thermostat does something worthwhile on the 3.5. Does the 3.5 suffer from "heat soak" like the 5.7? If there is no experience available on the forum, by all means, try it out the cooler thermostat and report back your experiences.

There is also the issue of whether a cooler than stock thermostat is beneficial in a really hot climate, especially under stop and go driving conditions. A colder thermostat does not provide more cooling, it just opens up at a lower temperature. I am curious as to whether at such brutal temperatures, the cooling system transfers enough heat to drop the temperature to about 180 degrees. The amount of heat transferred is proportional to the difference in temperature between the radiator and the cooling air passing over the radiator. At these temperatures there is only 55 degrees difference for the 180 degree thermostat so I doubt that the coolant temperature could be held at 180 degrees under these conditions.
 

·
Registered
Joined
·
204 Posts
Discussion Starter #14
There is no point in doing a mod that does nothing.

Show me some sort of proof that this will do nothing.

I'm pretty sure having a lower temp thermostat and cooling fans set to run nonstop at low speeds is going to help out at least a little bit. I'm not looking for major power increases, just piece of mind knowing that my motor isn't drowning in heat all day long. I'd liek to know that my cooling system is doing everything it can to keep temps down.

I don't think they engineer EVERY car to handle these kinds of temperatures on a daily basis. This is about as extreme as it gets. I see truckers install covers over their grilles to keep the cold air from the radiator so I'm assuming even though the vehicle was designed to run a certain way in certain environments, they didn't quite engineer it well enough to handle EVERY situation and environment.

I think it's safe to say there is room for improvement and it's not going to hurt anything to try to keep my motor a bit cooler during the hot summer months.
 

·
Premium Member
Joined
·
4,708 Posts
Apparently some of you guys missed this part in the first post:





When it's ~125* outside and I'm driving in stop and go traffic with the A/C on HI, I'm sure my cooling system is working it's ass off to keep the motor at a reasonable temperature.

At 125*F ambient, in stop-and-go traffic , with the A/C cranked to the max., your stock t-stat is wide open (as would be a lower temperature t-stat) and your radiator fan(s) are screaming. A lower t-stat will not lower your engine or "under the hood" temperature one bit under these operating conditions.

Even a lower temperature t-stat with a lower temperature "fan on" setting will just slightly impede the heating up process under the conditions you specify, but will not prevent identical end results.

The only thing that will help lower the temperatures under such conditions is a bigger radiator.

Installing a lower temparature t-stat without lowering the fan-on temperature setting(s) will only help under a narrow range of ambient temperature and driving conditions.

Now then, if you want to lower the engine and "under the hood" temperatures under more normal ambient temperature and driving conditions (which is what the 5.7L and 6.L HEMI guys (me included) are doing) then put in the lower t-stat and modify the fan-on temperature setting(s) with some kind of a hard-wired fan controller, or electronically with some kind of tuner (like the Diablo Sport Predator).
 

·
Registered
Joined
·
204 Posts
Discussion Starter #16
Ok, let's say I drive 50% stop and go and 50% highway. While I'm driving on the highway my thermostat is keeping my cooling system at ~180* efficiently. The thermostat is opening and closing during it's normal operations. Now, I enter my stop and go part of the commute. My cooling system is sitting at ~180* and busting it's ass to keep it there. The thermostat *might* be constantly open during this session, but of course we don't really know if it is or not.

Wouldn't it be better to keep the cooling system at a lower temp during highway use so when you do hit stop and go traffic the cooling system will be that much more ready to handle the extreme conditions of stop and go driving?

Either way it won't do a damn bit of harm to have this done and chances are it WILL do some good. I already have the Diablo installed. Might as well take advantage of some of the options, right? :dunno:
 

·
Premium Member
Joined
·
1,739 Posts
Show me some sort of proof that this will do nothing.
................................................
Don't get pi$$ed off because some of us give an opinion. I can't prove the mod will do nothing, but I can question whether it will do what you hope it will do. I don't have a 3.5 so I can't even offer personal experience with that motor.There doesn't appear to be a lot of experience on this site with cooler thermostats on 3.5's. Thermostats are a cheap mod so just try one out. We are particularly interested in whether the performance increases noticeably compared to the stock thermostat when the car is operating at 180 degrees verses the 200+ degrees stock temperature. You could also report whether there is any change in your gas mileage with a colder thermostat. As to keeping your engine cooler than stock under brutal temperature conditions, some of us tried to explain why we think it wouldn't help. Whether we are right or wrong, this is our honest opinion and is offered to be of help, not to be critical of your ideas.
 

·
Registered
Joined
·
204 Posts
Discussion Starter #18
Don't get pi$$ed off because some of us give an opinion. I can't prove the mod will do nothing, but I can question whether it will do what you hope it will do. I don't have a 3.5 so I can't even offer personal experience with that motor.There doesn't appear to be a lot of experience on this site with cooler thermostats on 3.5's. Thermostats are a cheap mod so just try one out. We are particularly interested in whether the performance increases noticeably compared to the stock thermostat when the car is operating at 180 degrees verses the 200+ degrees stock temperature. You could also report whether there is any change in your gas mileage with a colder thermostat. As to keeping your engine cooler than stock under brutal temperature conditions, some of us tried to explain why we think it wouldn't help. Whether we are right or wrong, this is our honest opinion and is offered to be of help, not to be critical of your ideas.
I wasn't getting pissed off, just irritated that you keep saying "Why bother?" and "there is no point" when you just admitted that you don't have any experience with it. :pat:

I guess I will just do it and see what happens REGARDLESS if I do or don't gain super crazy horsepower and torque out of my 3.5l monster. :dance:

This site is full of people who do things to their cars that they didn't "need" to do. They "wanted" to do it. No need to ask everybody who put rims or an intake on their car "Why bother?" or "What's the point?".
 

·
Registered
Joined
·
204 Posts
Discussion Starter #19
Then you make posts like this praising how great swapping to a lower thermostat is:
Bottom line, the thermostat mod is cheap and easy and well worth doing even if you don't do the fan mod.
I realize it's a different motor, but how can you come in here and say things like "Why bother" and "There is no point" when you say in another thread how great it is, even without changing fan settings????? :wtf1: Make up your mind.
 

·
Registered
Joined
·
1,305 Posts
SRSLY

just go do it and dont worry about what people say. Its a $5 part. if you don't like it swap it back out plain and simple.
 
1 - 20 of 36 Posts
Top