2.2 getting hot

[RussellW]

I just put my engine back in my 97 outback sport.I replaced the head gaskets,belt ,water pump,all idlers,new rad cap etc.I cleaned out water jacket while apart.I did this because it was blowing coolant out of reservoir but not over heating and not using coolant from radiator.The coolant was an awful rust color and I believe a previous owner put stop leak in it.The heater didn't blow very hot.My question is what is the cooling system bleed procedure,I think I just have air in it.It runs hot after about ten minutes on the highway.I currently have cooling system flush and water in the system and I'm getting ready to flush it.Before I tokk it apart it didn't run hot on the gauge.Any input would be appreciated.

[MilesFox]

these motors can be tricky to bleed the air out of. try fulling the block from the upper hose to get some coolant in the block, and unscrew the little bleeder on the radiator. you may have to add coolant in the bleeder when the car is running.

 

run the car til the radiator becomes warm, and also the lower hose. once the lower hose is warm, the thermostat has opened, and you can continue to fill in the radiator.

 

if you are afraid the heater core may be clogged, try reversing the lines to backflush it.

 

hope this hepls you. it is possible to overheat during the fill procedure, so be careful. there needs to be enough volume of coolant for the temp gauge to read it. if the coolant is too low, there will be a steam pocket as the block gets hot, but the gauge will read cold.

 

overall, a dry engine will take on about 2 gallons of coolant

[Rooster2]

It helps to tip the front of the car up to burp out air from the cooling system, when adding coolant and water. Suggest driving the front wheels up on ramps, or drive just the front wheels up on a curb to elevate the front of the car.

 

Post by MilesFox has some good ideas too.

[bheinen74]

when you burp it, you should also have heater settings on full heat, hottest temp setting, full heat. Jack up the front of the car, or drive it up a hill parked nose up, then the air can burp out the radiator fill cap when it is to operating temp. Then fill, repeat steps.

[RussellW]

I just went down to start flushing the cleaner out,got it up to temp and felt the bottom hose and it's staying cold.I put a new subaru thermostat in it but I think it's not opening.When I squeeze the bottom hose water comes out the rad cap without resistance,I don't think the rad is restricted,it's an aftermarket rad without top bleed screw.Should I get another thermostat or do I maybe have an air pocket on the engine side of the thermostat?Thanks for any input.

[NoahDL88]

Make sure the thermostat is installed correctly, if its backwards it won't open correctly.

 

I would get a genuine Subaru OEM thermostat, aftermarket thermostats seem to be hit or miss.

[eppoh]

Most likely air in the system. Patience is important with this. Be sure the front end is raised a little when burping it.

 

You said it has a subie thermostat. Good. I had the same problem on my 97. Just take your time and burp again., It will prolly work out.

 

Subie thermostats cannot be installed backwards.

[MilesFox]

^^^ patience is key. you can try holding the idle at 1500-2000 rpm to help circulate the coolant. you will want a nice swirl inside the radiator cap once the thermostat opens.

 

if filling the block by the upper hose doesnt work as well, you could try to fill the block through one of the heater hoses. this will get coolant behind the therostat in the water pump housing.

 

with the way the cooling system is designed, the air pocket gets stuck somewhere in the driver side water jacket, and takes some persuasion to move it through. be careful and watch your temp gauge

[RussellW]

Thanks to everyone,I'll be working on it again tomorrow.