So just recently my 96 lt1 began running hot when in idle or traffic but when i drive 25+mph the gauge goes back down to 1/4....if i let the car idle long enough it would reach the red... besides that i see no symptoms related to the cooling system or anything other then a bad heater core, would it be the coolant temp sensor

 

are the fans coming on? https://camaroforums.com/forum/93-02...ne-fans-54192/ what do you mean the heater core is bad, is it plugged. bleed air from cooling system. https://camaroforums.com/forum/lt1-l...-system-66742/ test the temp sensor on the water pump 4th Gen LT1 F-body Tech Articles

 

I don't think its the sensor, most likely the fans. Could be low coolant, check these if you haven't already.

 

when i say the heater core is bad i mean that when i turn the heater on i dont get warm heat and yeah the fans are coming on and there is coolant

 

The heater core is most likely clogged, and there is a good chance that the radiator is in the same condition. Being that the fans come on when the engine is hot indicates that the temp sensor is working fine.

 

are you hearing valve slam? if so your core is plugged. you may get away with flushing the heck out of it. i would say flush the heck outa the radiator too. best to flush core separate from the radiator or motor. take hoses lose and run a garden hose to it and run water through it both ways. orrr new core and new radiator. it may be that someone mixed the green and orange antifreeze, that then turns to gell gunk and plugs things up bad.

 

ill try and just take the core out clean it...but I can honestly say that the so called mechanics that did my radiator flush for me a valvoline most likely ****ed something up within the coolant system so ill give it a full run through

 

most times a shop will do a standard flush which is to hook in and do the whole system at once. if the system is cloged it can push the crab into the core or radiator passages and it sticks there rather than come out. doing them separate and running flush both ways makes for a better chance of success. if your gona go through the hassle of taking the core out i would pick up a new core. be careful not to over pressure them, cooling system is made to handle low pressure like to 20 lbs and a garden hose can have as much as 50 lbs. back flush the heater hoses too, theres a restrictor in one of them and it may be plugged.