Hello everyone,

I have a 2000 outback with 210,000 miles. I was driving the other day for about 15 minutes before i went to turn the heat on and noticed there was nothing but cold air coming out. I glanced at the temp gauge just as it pegged. I let it cool down and added some water before limping it home. After some fooling around with it i noticed that the top radiator hose was swelling as it would warm up. It would swell so much that when the fan turns on it rubs and makes an aweful sound. I checked the bottom radiator hose and it is cool to the touch when the top starts to swell, leading me to believe the thermostat needed swapped. I just swapped thermostats and i am now able to feel the bottom hose is getting warm as well. however, the top hose is still swelling. whenever I hit the throttle I can see the hose expand.

Have any of you had this issue or some similar? I'm afraid The head gasket will need replaced due to the rough idle upon start-up.

Did you replace the top hose?  Rubber hoses wear out and will swell as they get old.  

 

If its a new hose, I would do a block test on it and and see if you are showing hydrocarbons in the cooling system.  That year of engine was prone to external headgasket leaks unlike the EJ25D (95-99) which would blow internally and cause exhaust to pressurize the cooling system.

 

how much water did you have to add?  if you were down to the point of no heat, you've got a major coolant leak somewhere

Edited March 16, 201313 yr by torxxx

I didn't have to add much water. I didn't replace the hose. I am a bit skeptical that the system is running correctly and the hose is swelling just because its old. i have never had any issues with fan rubbing under normal driving conditions. I dont think its a stretch to say the hose is swelling 1/3 larger than it should be. 

You had no heat because the coolant was low.

You need to replace that upper hose ASAP. The inner and outer layers have separated and it will rupture soon and leave you on the side of the road.

 

I think you have another larger issue, which is a bad head gasket, but you'll have to get the cooling system filled properly and keep an eye on it for leaks for a couple of weeks.

 

Where did you get the thermostat? If it came from Subaru, good. If its an aftermarket it may still have problems.

+1 for running Subaru Thermostats.  They are 2 or 3x stronger.  I tell my customers you spend the 35 bucks for a subaru thermostat every 10 years, or you buy a napa one once a year and pay me each time to do it