Ok well I was driving my car recently and when i am moving the temp is right under 1/2 way (Cant think of the temp) then when i sit and idol the car's temp rapidly increases?? I checked the radiator only to find that all the fluids were topped. I am really confused on what to do now, someone told me to do a complete flush and refill. I am thinking i need a 160* therm. What do you guys think? Is it possible that my radiator cap isnt holding pressure to create a vacum??

 

Some good LT1 cooling system troubleshooting instructions are here: http://shbox.com/1/4th_gen_tech2.html#cooling

 

in the case of the ls1 it is normal for the temp to increase quite rapidly when the car is stopped and still running. This is primarily because of the fan setting. I am guessing that this temp setting is the same between ls1's and lt1's. The fans do not come on until close to 210 degrees, and even later than that for the high stage. The easiest way to fix this is with a programmer. Even the most basic programmer will adjust fan on/off settings. By merely doing this adjustment, my car no longer gets any hotter than normal running temp even in 100 degree weather and siting at a stop.

The physics behind it is, when the car is in motion there is air blowing through the radiator and that cools the coolant being circulated through the radiator. when the car is at a stop and the fans are off, there is no air movement through the radiator to cool the coolant. The water pump is doing nothing more than circulating hot coolant, and in all actuality is not helping. By setting the fans to come on earlier (in my case stage 1 is activated at 185, and will stay on till 180, and stage two from 195 till 185) the radiator and water pump can actually serve their purpose and circulate cooled coolant throughout the engine. This is probably the case with your car as well. I know the flow directions throughout the engine are reverse between the LS1 and the LT1's but regardless of that there still needs to be air passing though the radiator for the coolant system to function properly. You may want to research the stock fan on/off temps on and LT1 fbody, but i am guessing it is the same as for the LS1. If, not then I apologize.

Nathan

 

well, if the fluid is topped off, and the temp is rising rapidly (above normal operating temp) im going to have to vote for the water pump going out. check the weep hole on the bottom of the water pump and see if its leaking. the temp will rise a little bit, but not that much at a stop.

 

Ok well what i think i am going to do is have the radiator pumped and this time make sure to use the bleed vavle to make sure it gets done just like it says. Duh i should have looked at the manual Thanks alot guys i will keep you posted on what is goin on

 

So yeah today i was driving around and my radiator just started pouring out fluid everywhere then the car went way past the red zone as far as temp goes. I got it home ASAP and put it in the garage and put a bag of ice on the intake....what should i do??? I just bleed the lines last night and refilled all the coolant

 

are you sure it was the radiator puking the coolent and not the water pump?

check there first... if coolent is leaking out the weep hole at the bottom, then replace the water pump...

 

ok well when i turn the car off the resivour tank just shoots out coolant/water mix and steams up really bad....i couldnt find out the problem so i took it in to my mechanic

 

bad thermistat

replace, your done

 

will do thanks!

 

just as a side note, most often changing your TM should be a first resort(in a coolent problem), it is super simple and dont cost much $$$ and if it dont fix your problem , it did not hurt nothing to have a nice new one in there...

in this case it appears your TM is not opening properly allowing your coolent to circulate through your motor, so as your coolent heats up and expands, it has no place to go but the overflow resevoure...

I am almost 100% sure your problem is there, if by slim chance its not it, the 2 next places are the radiater cap(check this second) and the waterpump(this one last)

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