Overheating in at random times

its alot to take in PLEASE HELp!!

ok i have s few peoblems with my car nothing like this before i have taken it to the dealer for overheating and they changed the radiator cap the first time and told me that its fixed. then still the same took it back pissed they did all kinds of test and still nothing. i spoke to the tech and he said he did a block test and a compression test, and nothing all runs fine he said. well that was 8 moths ago and the problem still persists.

so 2 months ago to try and fix it myself i put a low temp thermostat. its a slp 160 stat and the first time i fired it up it got hot fast and then it just stayed there so i bled all the air pockets and everythigng i had done all my mods at once so the car was stock before i put the thermostat and the intake and all the stuff ive done to it below, so i had to test drive it.

on the test drive it drove normal and really really strong since i had it stock for almost a year. i got on the gas alot that night after i let the computer sort out wat i modded on it. it pulled strong. the temp stayed at the 4th notch like it was when it was stock, but never got hot at all. so i let it rest for like 3 hrs then on my way to my friends house witch is like 20 miles away. im driving and the temp doesnt get passed the 3rd notch on the temp gauge (when i was initially test driving it, it sat like stock right below the 4th notch). i thought that wasnt normal but i got on it on the belt way in vegas and still the same then on stop and go i get on it and its still the same.

so then i get to his house and let it sit for more then 2 hrs on my way back home the car is running at its normal temp like when it was stock right below the 4th notch. i was stunned but no choice to drive it. drove it normal and the car creeped over the half mark at a light as i was driving home. scared shitless i pull over and shut the car. after half an hr passed i then started it with the heater full blast and the car is cool now at this point but the car runs like crap throttle response sucked and then the car was running hott atleast above normal i know for sure.

and ever since that the car runs the same one day the car stays cool and the other day it stays warm. i thought it was my style of driving but i drove to work moderatly slow everyday for a hole month and that doesnt seem to change still gets hott on one day and then cool the next.

i got all the air pockets out and made sure that the coolant is topped off also the coolant res, and made sure the fan turns at normal running temp. everything seems to run fine. i think the fan turns on late but i cant figure it out. OHHHHHH BIG THING WHEN EVER IT OVER HEATS THE FANS ARE ON BUT RUN SLOW AND THEY TURN OFF EVEN THOUGH THE CAR IS STILL RUNNING HOTT. but the car has never ever hit above the the 2nd notch above the half.

i dont get it i simply am really feed up with trying and looking myself i need help BADDD

if u have any ideas or anything to help please please help

Hey,
Sounds like the temp on your car is running a bit inconsistent, but are you sure its "overheating"?
From your description it sounds as if your engine is running a little warmer than expected with a 160 thermostat, and technically it shouldnt be.
You mentioned you coolant is topped off, so thats good. Are you running the specified coolant in a roughly 50/50 mix or so?
Also if you could provide maybe more accurate engine temp #s it would help us all give you better advice.
If you hold the Mode and Set buttons down on that little round Trip Computer before you turn the ignition key (keep them depressed until key is turned to the start position) it will give you a little display screen of parameters to scroll through. One is digital readout of engine temp.
Maybe keep an eye on that and see exactly what your engine temps are at different driving conditions, and post your results on your thread here.
Even with a low temp thermostat, your engine coolant temp will rise and fall with driving conditions. Generally this is due to the computer programming of when the fans come on and what % speed they run at. Installing a low temp stat will only yield a lower overall engine temp while cruising with ample air flow through the radiator. When you come to a stop, the engine temp will rise as the factory fan temp settings are still in place and the fans wont start turning until 190* (or so)
Hope this helps.
--Glenn

Quote: Originally Posted by Glenn B... Hey, Sounds like the temp on your car is running a bit inconsistent, but are you sure its "overheating"? From your description it sounds as if your engine is running a little warmer than expected with a 160 thermostat, and technically it shouldnt be. You mentioned you coolant is topped off, so thats good. Are you running the specified coolant in a roughly 50/50 mix or so? Also if you could provide maybe more accurate engine temp #s it would help us all give you better advice. If you hold the Mode and Set buttons down on that little round Trip Computer before you turn the ignition key (keep them depressed until key is turned to the start position) it will give you a little display screen of parameters to scroll through. One is digital readout of engine temp. Maybe keep an eye on that and see exactly what your engine temps are at different driving conditions, and post your results on your thread here. Even with a low temp thermostat, your engine coolant temp will rise and fall with driving conditions. Generally this is due to the computer programming of when the fans come on and what % speed they run at. Installing a low temp stat will only yield a lower overall engine temp while cruising with ample air flow through the radiator. When you come to a stop, the engine temp will rise as the factory fan temp settings are still in place and the fans wont start turning until 190* (or so) Hope this helps. --Glenn

Hey thankds I dint kno about the dig temp gauge .. and I drove the car with the gauge on in the morning and it sits at 190 then 170 then 180 then 200 then 170 then 201 .. the low temps are from driving and I kno that's hou it should be .. but one time it went over 215 idk if it was after or befor fans..

Thanks for the info it should help me help you guys help me lmao that sounds confusing

Sounds right on. The fans would have to be reprogrammed to come on sooner then before.

On the freeway I see anywhere from 170 to 180 depending on the weather.

Once your off the freeway, going from light to light, the temp will raise until the fans kick on bringing it back down.

The gauge on the cluster is what I call a dummy gauge. If you were really over heating the dummy gauge would move into the red and the cluster would chime at you.

I have a 2004 so the fans are different but I have them come on a 190 and off at 185.
The 05/06 works off the temperature. The hotter the coolant the faster they spin.

So I think I found the problem but I don't kno exactly how to fix it ..

I'm sitting in the car right and just waiting. I'm looking at the temprature go all the way u. So I see it hit 195 and I'm thinking to my self the fans should be on by now I go look and nop no fans at all so I go maybe at 200 then it takes a few to get to 200 and still nothing so I wait till 225 and still nothing so I crank the ac all the way up and then move the climate to hott and gradually goes to 185 with the fans on constant and the blower motor blowing hott.. then I turn the ac off again then it gets to 230 with no fans on .. so then the fans aren't kicking on at all with out the ac.. wat sensor is that to replace and fix this is it something the dealer should handle or ?? And btw the weather in vegas its on 74 and still heats up ... WAT DO I DOOO!?

that sounds close enough to normal operation, dude. I don't necessarily agree that you are describing anything that is broken.
i understand that these engines are designed to run hot as shyte basically as you describe. the cooling system is pressurized ,
225 is not going to hurt it at all - that's nowhere near the boiling point of the coolant. if you had let it get a bit toastier, one of the fans would have come on, and then maybe the other, maybe at 235 and 245, or something like that.

i understand
the engine gets better mpg (or lower gallons per minute when stopped) when it is crazy hot like that, that's why it's an intentional design,
and will make less power.

turning on the AC should force both fans on, always, if I'm understanding correctly,
and makes the engine run cooler while at idle.

i'm pretty sure it's all by design. more knowledgeable crazy-ass mega-mods dudes will correct me wherever i'm wrong here i'm sure, which may be everywhere, as i am probably mishmashing LS1 and LS2 info, but hopefully somewhat applicable to your car dude.

225F sounds about right.

If you do some research in the dyno area you may find the stock settings.

Or ask what they are from the factory. Like i said the chime whould go off and warn you when the PCM thinks it's over heating.

Yes I understand that 225 is normal but then the fans don't kick on at all and it reaches up to 239 and the fans still don't turn on even if they run slow I would be good with that but they don't turn on at all at any temprature. I thought the fan should come on at like 190 but it doesn't tur on at that either.

So the problem has to be ther the day it really went passed the half mark was when I noticed the fans are not kicking on at all. I kno for a fact that it shouldn't go 240 without the fans.

Have you inspected the fan electrical connectors on the fan shroud to make sure they are plugged in well?
Any unresolved DTCs being displayed? (check engine light?)
Do your fans come on when you turn on the AC? (per Elis comment above.)
IIRC the AC command should tell 1 or both fans to kick on ( I think)
240* sounds high to not have any fan activity.
By then 1 or both fans should be doing something, I would think.
You have the factory GM tune on your car?
--Glenn

i have a factory tune, never had any programmers at all or a computer ever been hooked up.

the fans do turn on and both go one when the a/c is on. i have never touched the fans ever since ive had the car but maybe the dealer has but ill check all the connections and see wats up.

iv only had one dtc and it was the gas cap that had a recall on and i got that fixed but no dtc at all havnt seen one in years.

i kno i have to tune it but i want to finish my car with long tubes and a cam so im waiting for that but i know thats not what is making the fans delay..


and i kno the radiator is doing its job cus when i drive it the temp goes down but i have not seen the fans turn on at all since i noticed they dont turn on hahah.. so could it be the coolant temp sensor or a relay from the fan to the engine i have no idea?...

(thanks for all the ideas i really apriciate it EVERYONE!)

my normal temps are between 200-240 in stop & go traffic on a hot day... i always thought the temp can go upwards to 250 before anyone should worry.

are you topped off at the radiator cap? i've had a good pint or so of my coolant evaporate over the summer (surprisingly).

fluid is topped off.. and i understand that 200 to 240 is normal but is it normal for the car to creep over that normal point without the fand coming on. cus i still have yet to see that fans turn on at even those tempreatures.

my question is now, wats the temprature that the fans should come on i kno they might start up slow but whats that temp? or what is the normal operating temprature for the fan switch? at what point should the fan or fan be on (primary of secondary)?

http://www.ls1gto.com/forums/showthr...ight=fan+temps

I searched for a little bit and i came up with this.
See if this thread helps you figure out if your fans are activating correctly.
Hope this helps.
--Glenn

That's for the LS1. The LS2 is different.

Ask what the stock LS2 fan settings are in the tuning forum.

My guess is that's your right and the fans are not being told to come on for some reason because the LS2 fans should be turning by 200F and start spinning faster from there.

wait are all those readings for settings to be done when the car is tunned or when the car has that thermostat and how thae car should react. and i think all thos readings are for and ls1 i have an ls2..???


sorry for the slow respone been held up with a monster cold i wish the car cought a cold chill cus i dont think my s@#$ is running at the correct temps. lol