Strange over heating

stiguy · #1 03-21-2014, 07:18 AM

Okay so I've been dealing with a over heating problem and it doesn't matter if it's 30 or 90 outside. I drive 15miles to work one way half on side streets and the rest on the fwy. And it will try to over heat on both.

What it does is after driving for prob 20 min and it's all heated up if the rpm don't stay high it will start to overheat. So say I'm at a light and I see the temp climbing I have to rev the engine above 3500 then the temp will come down. Same thing happens right when I get off the fwy :/ I have noticed that if I start slowing down before my exit and downshift early it does seem to help it not overheat as fast.

I changed the thermostat didn't change a thing. Changed the water pump last week didn't change a thing. Tried flushing the system didn't help. Tested the fluid for a headgasket leak a few times all came back negitive. I did blow the cooling hose under the manifold last week.

So wondering if there is a build up of pressure? Maybe a plugged radiator? It looks clean tho.

Any ideas? Thx guys

1986nate · #2 03-21-2014, 05:31 PM

make sure you get all of the air out of the system?
Also, many times head gasket failures won't set off the various tests on EG/EJs especially if you're only doing them at idle and no load. What typically happens is one of two things, coolant is leaked into the combustion chamber burning off ever so slowly and in turn, combustion gases are leaking into the coolant heating it up. This will only happen at higher loads and RPM, then once the engine slows down, the water pump slows, pressure drops and you get flash boiling.

Tapani · #3 03-21-2014, 10:17 PM

See my post #13 in this thread:

http://www.subaru-svx.net/forum/showthread.php?t=58585

As Nate said, you need to load the engine for the test.

/T

stiguy · #4 03-21-2014, 11:34 PM

Quote:

Originally Posted by Tapani

See my post #13 in this thread:

http://www.subaru-svx.net/forum/showthread.php?t=58585

As Nate said, you need to load the engine for the test.

/T

Yeah I've tested it right as its been overheating like pulled over put a rag over the rad cap opened it up and tested it. Stayed blue the whole time.

Tapani · #5 03-22-2014, 03:02 AM

You may still want to double check. When it's not spitting coolant, i.e. before it over heats.

Just make a few full throttle spurts and then quickly to the test. You want to detect the gas bubbles from the gasket leak - not the steam bubbles from the flash boiling.

Just an idea and costs nothing if yo have the kit.

/T

stiguy · #6 03-22-2014, 04:30 AM

Quote:

Originally Posted by Tapani

You may still want to double check. When it's not spitting coolant, i.e. before it over heats.

Just make a few full throttle spurts and then quickly to the test. You want to detect the gas bubbles from the gasket leak - not the steam bubbles from the flash boiling.

Just an idea and costs nothing if yo have the kit.

/T

Okay got it I will try that out and report back thanks