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EJ22 Woes Overheating (negative combustion test)

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So the OBW decided to start overheating, my guess is that its the water pump.  I pulled the upper hose off and barely a trickle comes out when its idling.  Also did the burp procedure and did a Combustion gas test on the radiator numerous times with negative results,.. So,.. How much water, should the water pump,.. pump? 

 

1996 OBW EJ22

Edited by Subeast-EA81

If the engine is cold you won't see any flow through the radiator because the thermostat is closed.

 

When does it overheat? Sitting in traffic? Driving on the highway? Stop and go?

  • Author

Test done on hot engine.seams to overheat at an idle... but when I stick my finger in the radiator it's not hot at all

Could be a blockage in the radiator. Thermostat stuck closed. Or as mentioned, a bad water pump. If you end up needing one, I have a few good used ones laying around that you can have for a couple bucks plus shipping... if it comes to that. How new is the thermostat? OEM or aftermarket?

 

I am assuming you've topped it off and ensured that the coolant levels are full.

how are you testing flow of a hot engine?   disconnecting hoses of a hot engine results in explosiveness....

 

as said:

radiator is clogged

tstat is stuck

incorrect temp gauge

 

subaru water pump failure is very rare and would be one of the least likely items you can think of.

  • Author

fluids where topped off,.. i burped it,.. and subsequently ended up removing the discharge hose from the block, had my wife start it, and only a small trickle comes out at an idle with the temp gauge around 3/4 to hot.  the flow around 2000 doesn't seem sufficient for cooling.  it was running fine a few days ago then it sat for three days and this happens.  Condition of the T-stat unknown at this point, i personaly  hadn't delt with it yet, but looks like a T-belt and water pump kit is in my future.  thankfully the gas test is negative for now.

Edited by Subeast-EA81

  • Author

how are you testing flow of a hot engine?   disconnecting hoses of a hot engine results in explosiveness....

 

as said:

radiator is clogged

tstat is stuck

incorrect temp gauge

 

subaru water pump failure is very rare and would be one of the least likely items you can think of.

i had already relieved the pressure via the cap and was testing with the cap off.  Hose was pulled with the radiator cap off and engine off.  then started and idled up momentarily 

You're positive the cooling system was completely full and burped when it overheated the first time?

No recent work was done to it before the overheating incident?

 

If so that's going to be a clogged radiator, tstat, or headgaskets.

  • Author

Yeah I'm sure. I just got home from a short vacation and the car had sat. No signs of leaking. You suggest head gaskets however the compression gas tests (I did 5 tests) came up negitive. Is it still a possibility?

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