I swapped out a 2.5 for a 2.2. I did a new timing belt and waterpump during the swap. The engine starts right up and everything is working but for the cooling system. I keep getting air in the system. I originally had a OEM thermostat and I replaced it with a NAPA, no change. If I open the bleeder and cap I can get the air out and it will work for a day or 2 then I get more air in the system. Today I drove 35 miles without any coolant circulating. If it was not for it being 40 degrees outside I would of overheated. Any suggestions on a long term fix....

<<Today I drove 35 miles without any coolant circulating. If it was not for it being 40 degrees outside I would of overheated. >>

 

 

there had to be some coolant circulating or you would have overheated, no matter what the temp is. lets start with the basics:

how did you fill the coolant system (steps)?

did you use an OEM water pump?

50 / 50 coolant water mix?

Lets start even more basic.

 

subarus require subaru t-stats. So replace it with an oe stat, and while your at it get a new cap.

 

one of the many ways to fill a cooling system

 

Open the air bleed valve.

start the engine.

fill the cooling system SLOWLY with pre-mix.

wait for the t-stat to open (the coolant will surge out of the radiator)

slowly finish filling the radiator.

Put cap on radiator (close bleed valve), drive around block.

Make sure the overflow is filled to the hot line.

let car cool off.

 

Check coolant level when cold.

 

Another method is to do this with the car nose on ramps.

I keep getting air in the system. Any suggestions on a long term fix....

You, my friend, have a coolant leak. In order for air to be getting into the system, one of two things is happening. Either the coolant tank is emptying, or it's sucking in air as it cools. Either way, coolant is going somewhere, letting air in.

I don't get it. I also have a identical OBW that is doing the same thing now that I looked. I can drive it for 15 minutes one day and feel the bottom hose and its hot. Today I drive it for 30 minutes and its cold as could be. It can never goes above 1/2 on the temp guage. Anyone seen this before. Maybe I am creating issues.

Start with a genuine Sube thermostat and new rad cap.

I don't get it. I also have a identical OBW that is doing the same thing now that I looked. I can drive it for 15 minutes one day and feel the bottom hose and its hot. Today I drive it for 30 minutes and its cold as could be. It can never goes above 1/2 on the temp guage. Anyone seen this before. Maybe I am creating issues.

 

Can be a clogged radiator in your case.

 

nipper

a slightly blown head gasket will seep exhaust into the coolant displacing the fluid. watch for air bubbles rising out of the radiator when the car is running. its possible your motor swap has a head gasket issue