'97 cooling issues

[megaboss313]

my 1997 Subaru legacy gt has cooling issues and the guy I bought it from told me he got replaced the hosing and the thermostat and I don't know what else it could be so if any of you have had similar issues can you tell me what you did to solve it. 

[doublechaz]

First question:  was it a Subaru brand thermostat or a parts store unit?  I've had thermal issues on parts store units.  The OE unit runs me between 175 and 195 up a mountain in the summer.  The parts store unit would run me 210 to 225 on level ground in full winter.

 

Past that has it always had only pure distilled water and correct coolant?  If it has ever had the colors mixed or if it has ever had any tap water then I would get an IR temperature gun and scan all over the radiator while it is up to temp and see if there is variation across the panel.  This won't be fun to do as you might have to take out the fans and shroud to get a clear shot at it while avoiding cutting off your fingers.  The A/C blocks it from the front.

If that isn't the same temperature across the radiator side to side and up and down, then you may have blocked passages.  You might be able to get a slight idea on this if you take off the radiator cap when it is cold and see any scale growing on anything down in there.

All this assumes your radiator cap is working correctly, probably should have said that before.

 

If you have signs of a clogged radiator you could try a back flush with the chemical stuff, but the right way to fix it would be a new radiator.