Subaru Repair: 1998 subaru outback legacy overheating, outback legacy, subaru outback

Question






I have had the heads redone and correct gsakets installed, the block checked for cracks, replaced the water pump, radiator, belt and the thermostat 3 times. The car still overheats. The water does not circulate. The top hose gets hot but the bottom does not. If the thermostat is removed the top and bottom hoses both get warm and it doesn't overheat. What's the problem?

Answer
Hello John,

Its hard to know what is wrong.  The vehicle is reverse flow meaning the t-stat is at the bottom of the engine which you already know if you have taken it out. Have you tried bypassing the heater core, or using a infrared type thermometer to look for temperature variations in the cooling system?  I am curious as to how the block was checked for cracks as they usually crack in the cylinder wall and sometimes these cracks cant be seen unless the pistons are removed if the crack is at the bottom of the cylinder liner which I have observed more than once.  Remember any air trapped or introduced into the cooling system can spell disaster if an air pocket gets trapped at the t-stat as the t-stat needs hot coolant to open and not hot air. Lastly are you using Genuine parts?  I have seen many an aftermarket T-stat let someone down.

Justin

All Wheel Drive Auto