SC Overheating

Lsquared

Registered User
:mad: I had just replaced the Radiator with a brand new one, new coolant, and the hoses too because it had a crack in one of the seams.

I drove the car for a good few weeks and then all of a sudden on my way to work i had no heat and the car started to get hot. The coolant was overflowing out of the reservoir. I shut it down and went to work and when i came out it ran fine with full heat and cool temp.

Soo i replaced the thermostat thinking that it must have been sticking.

A few weeks later i was leaving home and the car overheated again. I had to leave it overnight and then drove it home in the morning and it ran fine.

I was busy at College so i let it sit at my parents house for a few months until i had time to address the overheating. Now i got it started pulled it into the garage and the blower motor wasn't working on the heater. Sooo i left it alone for an hour or two to warm up in the shop and magically it worked but no heat.

Soo now i have no heat but the car is not overheating at this time and the thermostat is opening and closing at 180 just like it should. I am am not sure what to check because aparently i still have the overheating issue, but its just intermitten and must be connected to the no heat situation i currently have.

Any help would be much appreciated.
Laurence
 
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Sounds like maybe some air was left trapped in the system. What process did you use to bleed air during repairs?

  • Any garbage in the overflow tank?
  • What year?
  • How many miles?
  • Is it very cold there now?
  • What percentage of coolant vs. water mix did you use?
  • Do you know how to check for issues with headgaskets?
 
*1994 SC, auto, 130k
*I believe that the overflow tank is pretty clean, i had cleaned it awhile ago. I was thinking that somthing could have got into the system, maybe even from the new radiator and worked its way to the heating system and it now messing with that.
*I used a prestone and cut it 50/50. I had just replaced the radiator so whatever coolant came out with the radiator off and hoses off is what i took out. I didn't do any flusing of the system.
*After the new radiator and coolant was full i ran the car with the bleed cap on top of the engine open to release any air from the system.
*The temp had been pretty cold as the car was sitting outside during the past few winter months in Wisconsin, 20 degrees or colder, but the initial breakdown was in the fall with more like 40 degree temps. Now its in a heated garage while im working on it.
*I do not know how to check for head gasket failure. I believe that they were replaced in like 97 before i had the car due to a recall. The car runs good and does not produce white smoke out the exhaust. It only has been recently overheating on random occasions since the new radiator.
 
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do u have a chip to change the radiator fan's on/off settings ? with that 180 t-stat in there and no programming the coolant will flow out of the engine at 180 and go straight thru the radiator and back into the motor. the fan wont come on til 220 or so with factory settings.

also i think there may be a clog somewhere in there.
 
I dont have it chipped. The only mods are removed air silencer, CAI, MAF, and exhaust for the most part. I will check the fan if i get it to overheat again on me, but im pretty sure that it was running just fine.

The 180 thermostat is the stock thermostat if i'm not mistaken. Should i be running something other than that?

I am also thinking that it must have gotten somthing into the system when i replaced the radiator. I am not sure what or how, but i'm thinking i will have to flush the system to figure that one out.

Any suggestions on completly fulshing the cooling system, I havent done that on this car only on older cars?

Thanks.
 
195 degrees is the stock t-stat temp.

as far as flushing the engine out....u said there's sometimes no heat in the car. that makes me think theres something blocking coolant going into the heater core. maybe try backflushing the heater core ?

and maybe spraying water into the thermostat opening and then turning the water pump pulley to flush it out. never tried this but i think it would work.
 
I will have to give that a try. I think i found the inlet and outlet for the heater core so i will have to see if i can flush anything out of there.

Thanks for the ideas

Laurence
 
i think the inlet and outlet are right behind the inlet plenum.

i at least know they're to the right of the a/c tubes
 
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