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Hello all,
I have a cam only ls1 that has some pretty bad temps(creeps up to 230+) when idleing in traffic during nevada summers(think when its 105-115 outside). Vehicle currently has the lt1 radiator in place of the ls1, 180 temp stat.
Fan one is set to come on at 185 and fan 2 comes on at 188. Fans confirmed to work(they are also new).
Temps normalize only a little bit when moving again. Can hear coolant percolating in the overflow tank but not loosing any as of yet
Im reading the temps via hptuners as we all know the dash gauge isnt super accurate
1: Is this expected considering the hot ambient temps?
2: would a thick radiator from like Dewitts,be-cool or ECP help with keeping the temps down during the hot summers?
Last edited by ramba_ral; Aug 7, 2025 at 04:29 PM.
Hello all,
I have a cam only ls1 that has some pretty bad temps(creeps up to 230+) when idleing in traffic during nevada summers(think when its 105-115 outside). Vehicle currently has the lt1 radiator in place of the ls1, 180 temp stat.
Fan one is set to come on at 185 and fan 2 comes on at 188. Fans confirmed to work(they are also new).
Temps normalize only a little bit when moving again. Can hear coolant percolating in the overflow tank but not loosing any as of yet
Im reading the temps via hptuners as we all know the dash gauge isnt super accurate
1: Is this expected considering the hot ambient temps?
2: would a thick radiator from like Dewitts,be-cool or ECP help with keeping the temps down during the hot summers?
That does sound too hot to be comfortable with. I have never tried one of the expensive all aluminum radiators, they have one for around 200 on Amazon, looks just like the real expensive ones, those may help keep the temp down. Either programming the fans to come on at a sooner time or wire them to a switch where you have full control of them and can basically run them at all times. Thermostat would get a 160, hell when it's that hot outside probably don't need one, TBH what I would consider and I've done this many times would be flush the cooling system then replace every bit of it, water pump tstat hoses and rad, then vacuum fill the cooling system with clean coolant and throw in 1 or 2.bottles of additive like hyper lube super coolant. 1 car I did all that too and I never have seen the temp move past 170 regardless of outside temp or driving conditions
Hello all,
I have a cam only ls1 that has some pretty bad temps(creeps up to 230+) when idleing in traffic during nevada summers(think when its 105-115 outside). Vehicle currently has the lt1 radiator in place of the ls1, 180 temp stat.
Fan one is set to come on at 185 and fan 2 comes on at 188. Fans confirmed to work(they are also new).
Temps normalize only a little bit when moving again. Can hear coolant percolating in the overflow tank but not loosing any as of yet
Im reading the temps via hptuners as we all know the dash gauge isnt super accurate
1: Is this expected considering the hot ambient temps?
2: would a thick radiator from like Dewitts,be-cool or ECP help with keeping the temps down during the hot summers?
Perfectly normal in that kind of heat. GM does not even have the fan enable on most vehicles until over 220F.
I have a LT1 rad...160 stat....never had it that high in texas heat
Well there's something wrong with u becuz apparently 230 is perfectly safe and nobody should be worried about their gage creeping up a millimeter away from the red line
Forgot to clarify in the post its 2002 ls1 firebird
Im running the stock fans so they are pulling whatever the stock fan setup pulls for cfm
I took it for a test drive for some datalogging. It looks like it takes about 25 min for it to get that hot and as soon as I come to a stop at about the 30min mark the temps shoot up.
sounds like to me its getting heatsoaked.
a side question, I did get it tuned after I installed the cam. Could the tune have something to deal with it?
Last edited by ramba_ral; Aug 8, 2025 at 09:29 AM.
Well there's something wrong with u becuz apparently 230 is perfectly safe and nobody should be worried about their gage creeping up a millimeter away from the red line
Actually, 230°F *is* perfectly safe as the factory fan programming from GM doesn't even engage the high speed fan setting until 235°F (A/C off). Obviously if this temp was seriously bad, they would activate high speed setting sooner. Also, the gauge wouldn't be a millimeter away from the red zone at 230°F. Red zone doesn't start until about 255°F. The gauge will mostly stay a hair under or over the 210° mark for any actual temp between about 190-230°F as it is buffered. The only reason that the OP is able to read true temp is because he's using a scanner, otherwise it shouldn't be showing anything alarming on the gauge at that temp.
Having said all of that, the OP would likely benefit from a larger capacity radiator to help prevent heat soak in that climate, but this shouldn't be "required" for a relatively stock car. It's also possible that the stock fans are getting weak, and/or that there is some amount of debris/blockage in the A/C condenser that's limiting air flow through the radiator. Or maybe a missing piece of the air dam? With ambient temps of 105-115°F, if anything is "off" I would expect that cooling would be very difficult.
Actually, 230°F *is* perfectly safe as the factory fan programming from GM doesn't even engage the high speed fan setting until 235°F (A/C off). Obviously if this temp was seriously bad, they would activate high speed setting sooner. Also, the gauge wouldn't be a millimeter away from the red zone at 230°F. Red zone doesn't start until about 255°F. The gauge will mostly stay a hair under or over the 210° mark for any actual temp between about 190-230°F as it is buffered. The only reason that the OP is able to read true temp is because he's using a scanner, otherwise it shouldn't be showing anything alarming on the gauge at that temp.
Having said all of that, the OP would likely benefit from a larger capacity radiator to help prevent heat soak in that climate, but this shouldn't be "required" for a relatively stock car. It's also possible that the stock fans are getting weak, and/or that there is some amount of debris/blockage in the A/C condenser that's limiting air flow through the radiator. Or maybe a missing piece of the air dam? With ambient temps of 105-115°F, if anything is "off" I would expect that cooling would be very difficult.
Listen I'm just ****-talking I'm bored i believe u sir
So the dash gauge does go past the 210 mark and gets close to the 3/4 mark if I let it keep climbing. normally I shut it down so im not sure how hot it will get.
In terms if debris or blockage, its all clear no debris. Air dam is installed and intact. Fans shouldnt be week as I got new ones.
Im thinking its heat soak but im open to things/ideas
So the dash gauge does go past the 210 mark and gets close to the 3/4 mark if I let it keep climbing. normally I shut it down so im not sure how hot it will get.
In terms if debris or blockage, its all clear no debris. Air dam is installed and intact. Fans shouldnt be week as I got new ones.
Im thinking its heat soak but im open to things/ideas
Did you flush the condenser fins with water when changing the radiator? It might *look* clear, but there could still be small amounts of build-up that prevent airflow to some degree. You're operating in extreme conditions, so even small things can matter.
Where did you source the replacement fans? Are they OEM? Quality could be suspect.
Has it always behaved this way since you've owned it? Did you notice any change or improvement at all when you replaced all cooling system components? Also, what is your anti-freeze to water ratio?
I agree that 230-240 is pretty much the max OEM's run these days so its likely not hurting anything at that level. I wouldn't run mine there or go racing with my temps that high. But it shouldn't melt down or anything.
Might also verify the temps are actually that high. The factory LS location at the head reads hot IMO. Its always been 5-10* more than at the radiator hose on my stuff. Vacuum bleed/fill can sometimes make a huge diff too.
Howe makes some of the best cores out there and you'd have no trouble keeping it down in the 170-180 range with one of those and capable fan(s). Just have to decide if its worth it to ya. Also the new brushless gm fans flow like 3-4x the air as what you run now. One of those would also "fix" your issue.
In my poor guy hotrodder days I used the windshield washer pump and reservoir (filled w tap water) to mist the radiator at stop lights when it would start to get hot. Used tiny spray paint cap nozzles so it didn't run through much water. Worked better than you'd think.
Last edited by Forcefed86; Aug 8, 2025 at 03:56 PM.
i have the ECP radiator for the auto trans in my 02 WS6. it keeps the temps at 180-185 with a 160 t-stat, PCM tune for the lower fan on/off settings. I did have a problem in the beginning, it would run at 192-198 and was getting air in the system from one of the ports. One of the fittings wasn't tightened down all the way and was leaking a lil bit of coolant around that area. The attached pic shows the fitting that was leaking but i think that radiator is the frostbite one.
Just had to tighten it about a quarter or half a turn and no more leaks and now it runs at 185 in 90+ weather. I did a quick video of the engine bay of my car and you can kinda see the ECP radiator on there.
Did you flush the condenser fins with water when changing the radiator? It might *look* clear, but there could still be small amounts of build-up that prevent airflow to some degree. You're operating in extreme conditions, so even small things can matter.
Where did you source the replacement fans? Are they OEM? Quality could be suspect.
Has it always behaved this way since you've owned it? Did you notice any change or improvement at all when you replaced all cooling system components? Also, what is your anti-freeze to water ratio?
I flushed the condenser with the stuff you use on ac systems then flushed the fins out with water.
I always fit the biggest rad I can on my LS swaps. No way I would use a Amazon cheap radiator.
Speak directly to Afco, Dewitts, Griffin, Be Cool about your issues and see what they think.
Just a question. With the rad pic above what's up with the two inlets?
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Question on temps when its 105+ degrees out 
