Subaru WRX Forum banner
1 - 17 of 17 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter · #1 ·
I had a little bit of overheating a while back so trying to be pro active i changed out the thermostat and filled the car up with new coolant. After doing that it seems the car started overheating more and worst (yes i burped it). I have a Mishimoto rad aswell and all the hoses were changed but replaced the upper rad hose a second time because the alternator was rubbing on it. After burping and throwing new coolant in atleast 4 times now it seems to just keep overheating.

After burping the car will run solid for 30 ish minutes and then overheat. When it overheats i pull over cool the car down and then when i start driving again i gotta pull over 1km down the road and do it all over again. My overflow tank also fills up a little bit after burping the car but only does it a certain amount and only one time.
Water pump has been changed, burped with heat on max, not blowing smoke out of the exhaust, coolant comes out bright green when flushing, no loss of power or leaks. I don’t know what the issue is how how it got so bad from me trying to get ahead and change it before it got worst. Anybody have an idea on what’s going on? Going in soon to get pressure tested and to test the oil and coolant to see if it’s head gasket.
 

·
Super Moderator (Actually a SuperSpy)
Joined
·
19,637 Posts
Do you have circulation?
 

·
Super Moderator (Actually a SuperSpy)
Joined
·
19,637 Posts
Let the car go stone cold.

Remove the radiator cap (if you have two, I'd do the one by the turbo reservoir).

Turn on the engine and let the car warm up as if you are going to burp it, and just wait and see if you see circulation once the thermostat opens.

Then burp the system anyway.

Or you can use an IR thermometer and see that there is no longer a temperature difference before and after the thermostat once it opens, and see that there is a temperature difference between the top hose and the bottom hose.
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #5 ·
Let the car go stone cold.

Remove the radiator cap (if you have two, I'd do the one by the turbo reservoir).

Turn on the engine and let the car warm up as if you are going to burp it, and just wait and see if you see circulation once the thermostat opens.

Then burp the system anyway.

Or you can use an IR thermometer and see that there is no longer a temperature difference before and after the thermostat once it opens, and see that there is a temperature difference between the top hose and the bottom hose.
There is a temperature difference in the upper and bottom rad hose thankfully. If i take the radiator cap off well the cars running isn’t it just gonna shoot all the coolant out because of the pressure?
 

·
Super Moderator (Actually a SuperSpy)
Joined
·
19,637 Posts
Not while the car is running.

Let the car go stone cold.

Then remove the cap and start the car.

Wait a minute though -- because of the nature of your question/comment, I have to ask: HOW did you burp the system?
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #7 ·
Not while the car is running.

Let the car go stone cold.

Then remove the cap and start the car.

Wait a minute though -- because of the nature of your question/comment, I have to ask: HOW did you burp the system?
i got a funnel on the expansion tank i think it’s called, fit perfectly in the seal and then we’ll the car was cold and turned off i put coolant in and squeezed the hoses until no more bubbles came out, then started the car and cranked the heat and let it idle for 30 min with a few revs every few min
 

·
Super Moderator (Actually a SuperSpy)
Joined
·
19,637 Posts
That’s reasonable. At some point maybe 5 minutes in, the thermostat should have opened and you should have had to top up the coolant as the level dropped.
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #9 ·
That’s reasonable. At some point maybe 5 minutes in, the thermostat should have opened and you should have had to top up the coolant as the level dropped.
yea i have no clue what it is, burped it twice since the last coolant flush but it seems like it’s dumping all the extra coolant to the overflow and that’s making the air pockets. Not sure why it’s doing that though
 

·
Super Moderator (Actually a SuperSpy)
Joined
·
19,637 Posts
So you added more coolant during the burping, as necessary?
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #11 ·
So you added more coolant during the burping, as necessary?
yea i just put in coolant when it went down and took out when it went up, then plugged the bottom when the bubbles stopped and then pulled it out. Any idea why i’m getting coolant going back into the overflow?
 

·
Super Moderator (Actually a SuperSpy)
Joined
·
19,637 Posts
Assuming you have circulation: My guesses in order of increasing cost are an air pocket despite your burp attempts, a faulty radiator cap, or a head gasket.
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #13 ·
Assuming you have circulation: My guesses in order of increasing cost are an air pocket despite your burp attempts, a faulty radiator cap, or a head gasket.
just go back to a oem radiator cap? And the coolant that goes back to the overflow only does it once and never again.
 

·
Super Moderator (Actually a SuperSpy)
Joined
·
19,637 Posts
Burp and top up while doing so, replace both caps with the correct ones, and pressure test the system, in that order.
 

·
Registered
Joined
·
19 Posts
Make sure you have the caps in the correct locations. The lower pressure cap goes by the turbo. The higher pressure cap goes on the radiator. If you get them backwards your system will lose coolant through the expansion tank.
 
1 - 17 of 17 Posts
Top