Cooling issues in hot weather, tried evrything

[bvass]

Hi guys I have been having some cooling issues with my 2ga GSX(mods are up to date in my profile) since i got it a year ago and nothing i have done seem to help. I'm running out of ideas

I live in AZ where summer temps reach 120. When it gets over 100 my car's temp starts to rise. I have gotten up to 220F with normal driving and my AC turned on. When i turn the AC off the temperature slowly comes back to normal. The car gets hotter at higher speeds(i think temperature rise is directly related to engine load, but I could be wrong) I checked the temp with a data logging software and visually on the gauge

Here is what i have tried:

flushed the system
confirmed that both fans work properly
installed new radiator cap
installed new thermostat
installed new water pump
installed new aluminum radiator (2.5 inch thick)
tried coolant mixtures of 50/50, 30/70, just water, I even tried water wetter(i know it doesn't lower the coolant temperature)
compression is 175 across the board
hydro-carbon test was fine
no smoke comes out of the exhaust
there are no leaks (on the cooling system)
there is no trapped air in the system and the heater blows really hot
i don't have an FMIC
all the shrouds guiding the air to the radiator are in place
nothing is blocking airflow to the radiator

I haven't replaced the temp sensor yet, but it seems to work fine when the outside temperature is less than 100. I will change it soon anyway but I don't think this is the issue.

As i said I'm out of ideas. I was wandering if it is possible that the heat in the engine bay can heat up the sensor (close to the thermostat) so that it give false readings?

Is there anything else I can do?

 

[No_Skillz]

Sounds like you've done your research on this problem. A few things that jump to mind that you can check are: make sure the fins on your AC condenser are straight so airflow can get to your radiator, see that your radiator fins are straight, make sure you've gotten all of the bubbles out of the system, and make sure you have a headshield on. I've heard that ceramic coating of the manifold and heatshield will reduce the radiant heat off of them.

120 degrees is damn hot, so I don't think that there's anything wrong with the car, just that things have to be running perfectly to handle those temps.

 

[Nicks2319]

Maybe go with a better radiator, I know you said you got a new one, but maybe a Fluidyne would help. Also, get some higher power FAL fans, and do the fan relay mod (where both fans turn on instead of just one). Also, you might want to just wire up a switch into your empty dash plate that will make both fans come on whenever you want them to.

http://vfaq.com/mods/wayback/2gcoolingfan.html

 

[bvass]

Sounds like you've done your research on this problem. A few things that jump to mind that you can check are: make sure the fins on your AC condenser are straight so airflow can get to your radiator, see that your radiator fins are straight, make sure you've gotten all of the bubbles out of the system, and make sure you have a headshield on. I've heard that ceramic coating of the manifold and heatshield will reduce the radiant heat off of them.

120 degrees is damn hot, so I don't think that there's anything wrong with the car, just that things have to be running perfectly to handle those temps.

Thanks for the quick reply. Fins are straight, there are no bubbles and the heatshield is on. 120 degrees is indeed very hot, but I talked to other DSMrs and they don't get hot at all. Even people with FMICs don't get hot. Ceramic coating is a good idea, and I'm sure it will help but the underlying issue will remain.

 

[bvass]

Maybe go with a better radiator, I know you said you got a new one, but maybe a Fluidyne would help. Also, get some higher power FAL fans, and do the fan relay mod (where both fans turn on instead of just one). Also, you might want to just wire up a switch into your empty dash plate that will make both fans come on whenever you want them to.

http://vfaq.com/mods/wayback/2gcoolingfan.html

I do have a big aluminum radiator similar to the Fluidine. I don't think the fans are an issue since the car gets warm at 70-80mph

 

[romeen]

One more option is to consider replacing your stock fans with aftermarket ones like the Flex-A-Lite. They pull quite a bit more air than the stock ones. FAL also makes an adjustable thermostat switch which allows you to control the temperature at which the fans turn on. I have this setup and it is quite effective. Other benefits are that they are significantly slimmer. I can easily remove/replace my turbo and manifold without removing the fans. They also weigh less than the heavy stock fans. However, they are not cheap--around $360. If you want anymore info about the fans let me know.

Edit: Just read the other posts since No Skillz, I was beaten to the punch. My computer is painfully slow today.

 

[bvass]

One thing i forgot to mention is that there was absolutely no change in the way the car behaved(temperature wise) after installing all these parts, which i find weired.

Any opinions on the possibility of the temp sensor getting hot from the heat in the engine bay?

Also I noticed if the car stays on idle for 5-10 minutes and the temperature rises and then I start driving it the temperature goes down right away (not to normal operating temperature just lower). If i drive the car and i shut it down when the temp is lets 210 and i get back in it 5 minutes later the temp is 220 when i start the engine and immediately drops to 210.

 

[1gnow2g]

bvass:

I have always seen my Eclipses run cooler when I
turn on the AC. This is, as the second fan is forced
on. You are saying that the second fan is resulting
in less cooling then the additional heat generated
from the AC load. Hard to understand, unless the coolant
flow rate is poor. When I did the internals on my 'E'
engine, there was a boat load of casting sand in the
coolant paths which I removed. You could have poor
flow, maybe a dye test, but you would need a "good"
car for comparison.

 

[tqmx1]

I have not seen it listed but have you tried a 180F. thermostat? the stockers are 195F so it does not leave you with a lot of room to play with.

With a good cap and coolant mixture you should be able to go up to 240F and still be safe.

 

[No_Skillz]

One thing i forgot to mention is that there was absolutely no change in the way the car behaved(temperature wise) after installing all these parts, which i find weired.

Any opinions on the possibility of the temp sensor getting hot from the heat in the engine bay?

Also I noticed if the car stays on idle for 5-10 minutes and the temperature rises and then I start driving it the temperature goes down right away (not to normal operating temperature just lower). If i drive the car and i shut it down when the temp is lets 210 and i get back in it 5 minutes later the temp is 220 when i start the engine and immediately drops to 210.

I'm starting to get confused... earlier you said you only overheated when you're cruising at 70-80. Now are you saying that you're overheating when you are at idle? The two problems have different approaches, since overheating at idle is generally the fans and overheating during cruising is about airflow and coolant flow to the radiator and motor.

What you described could be your temperature sensor going bad, but in my mind it could also be a result of the water pump coming on and bringing coolant from your radiator that's less hot. However, you can still try and replace the sensor, since they're pretty cheap. Also, let us know about the status of your thermostat as others have suggested.

 

[bvass]

I have a 180 thermostat. The car gets hot both at idle and while driving although it doesn't get as hot at idle as it does when there is significant load on the engine. I ordered a new temp sensor and I will replace it as soon as it arrives. However I'm not going to be able to tell if that fixed the problem until the temperature in Phoenix rises above 100. Right now the car is running fine since it is "only" 90 degrees outside.

 

[JenkyJ]

I had the same issue, getting hot at idle, and driving over 80 with a/c on. I use redline water wetter, mitshimoto racing thermostat, used dsm link with fal fans to cut on 40 deg earlier, the therm. stat is a 160 deg. which causes the car to take a long time to get warm but thats cool with me.

 

[TheAButton]

I took out my A/C heat raditor thing and my car has never even show signs of over-heating since, so I'd suggest that you, but my a/c also didn't work so I didn't care that I took the whole system out.

 

[BoostFrenzy]

Seriously? This post is THREE YEARS old!

 

[JonathanNL]

Seriously? This post is THREE YEARS old!

Yes, we should all praise the new member/lurker for using the search button.