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2006 Legacy 2.5i (SOHC) Weird Cooling Readings on Guage


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Hello,

 

So, the engine is all back together.

 

For the initial start-up I did the Subaru Relearn after a long time without a battery. I didn't touch the accelerator pedal during initial start, and let it idle for at least 40 minutes. 

During this time I had Lisle 24680 Spill-Free Funnel attached to the Radiator Filler port, and the front end of the car was elevated and up on jack stand to help trapped air bubbles from the system for the first 30 minutes. post-66150-0-27142200-1498358261_thumb.jpg

 

So, I was letting the car idle for a long time, when I noticed the Temperature Gauge was climbing up towards HOT area on the gauge. I did not let it get there though. FYI, both fans are running the way there are supposed to. The Anti-Freeze in Subaru brand for my year of car.

 

After I turned the car off for a few minutes the temp came back to normal (Gauge was like just below the 9 'o'clock position)  

Is this a air bubble that is trapped or maybe a bad thermostat?

 

Thoughts?

 

This is what is NEW on the Engine Cooling Side: (All Subaru Parts)

Radiator

Water Pump

Thermostat & Thermostat Housing

Both Upper & Lower Radiator Hoses

 

 

 

 

 

 

 

 

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Probably air in the system. Provided you used an OEM or OEM style thermostat (bunch of topics on here about thermostats) 

 

I've had issues with bleeding air from the system on a bunch of subarus. Typical, in my experience, the heatercore doesn't like to fill up, and because of that, coolant doesn't circulate properly and can sometimes even cause the thermostat not to open.

 

Do you know if the vents were blowing hot air? Because of they were, it might be the thermostat. But if they weren't blowing hot air, you have air in the heater core you need to get out.

 

Again, in my experience, a trick I learned from a guy on iATN is to get the heater core to fill all the way. Step on the gas pedal and get the RPMs to shoot up (not much over 3k though) and then let them settle, and continue to do that until the vents blow hot (obviously monitoring coolant temp and don't let it overheat)

I tend to have to do that on most subarus I open the cooling system on, even after using my airlift.

 

Good luck!

 

Also, do you have a scan tool you can monitor live data with? Most Subaru's I've worked on in the 08' area, fans turn on around 212 degrees F and shut off around 204 (the shut off depends a lot though, but the turn on is almost always right around 212 +/- 2 degrees)

Edited by golucky66
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Probably air in the system. Provided you used an OEM or OEM style thermostat (bunch of topics on here about thermostats) 

 

I've had issues with bleeding air from the system on a bunch of subarus. Typical, in my experience, the heater core doesn't like to fill up, and because of that, coolant doesn't circulate properly and can sometimes even cause the thermostat not to open.

 

Do you know if the vents were blowing hot air? Because of they were, it might be the thermostat. But if they weren't blowing hot air, you have air in the heater core you need to get out.

 

Again, in my experience, a trick I learned from a guy on iATN is to get the heater core to fill all the way. Step on the gas pedal and get the RPMs to shoot up (not much over 3k though) and then let them settle, and continue to do that until the vents blow hot (obviously monitoring coolant temp and don't let it overheat)

I tend to have to do that on most subarus I open the cooling system on, even after using my airlift.

 

Good luck!

 

Also, do you have a scan tool you can monitor live data with? Most Subaru's I've worked on in the 08' area, fans turn on around 212 degrees F and shut off around 204 (the shut off depends a lot though, but the turn on is almost always right around 212 +/- 2 degrees)

Hey, I never thought about the Heater Core issue. I should have because the heater core probably site higher than the engine, and I even put on New Heater Core hoses.

 

I will try what you said in regards to increase the RPM..

 

Also what is: AIRLIFT? 

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Air

Burp it again and read here how others do it.

 

Nose up. Drive, top off, drive top off, drive....until the air is gone.

 

Thermostat failure is way less frequent than it's talked about. Pull it out and boil it to test.

Edited by grossgary
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Hey, I never thought about the Heater Core issue. I should have because the heater core probably site higher than the engine, and I even put on New Heater Core hoses.

 

I will try what you said in regards to increase the RPM..

 

Also what is: AIRLIFT? 

 

An Airlift is just a tool for a technician to "in theory" fill the system without getting air in. 

It works by pulling a vacuum on the entire system, and then you stick the hose into the coolant, open the valve, and the vacuum in the system will pull in the coolant. 

I'm not saying get one, please don't bother. It can be helpful for a technician, but not necessary on any car. 

 

If you can't get the RPM trick to work, worst case if you could pull the upper heat core hose off, fill the heater core with coolant (as much as it will take and then start the process over again. I doubt you'd need to do that but another option. 

 

Many ways to get air out of the system. Just gotta find the one that works in your situation. 

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Air

Burp it again and read here how others do it.

 

Nose up. Drive, top off, drive top off, drive....until the air is gone.

 

Thermostat failure is way less frequent than it's talked about. Pull it out and boil it to test.

Hey, I did the Boil Test on it a few day after getting it.   I will put the Nose Up again to help move the air out.

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What you should have done, instead of turning it off, was rev the engine to 4,000 rpm a few times rapidly when the gauge started to climb. The increased water pump pressure will push the air out.

 

Remember we do this like twice a day. Trust me. You don't need to elevate it but it won't hurt anything. Just rev the engine to clear the air pocket.

 

I have tried the airlift. The results are mixed and it's a pain in the butt compared to the funnel and a few whacks on the loud pedal.

 

GD

Edited by GeneralDisorder
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What you should have done, instead of turning it off, was rev the engine to 4,000 rpm a few times rapidly when the gauge started to climb. The increased water pump pressure will push the air out.

 

Remember we do this like twice a day. Trust me. You don't need to elevate it but it won't hurt anything. Just rev the engine to clear the air pocket.

 

I have tried the airlift. The results are mixed and it's a pain in the butt compared to the funnel and a few whacks on the loud pedal.

 

GD

Thanks, I will try it tomorrow...

 

Should I still attach the Lisle Spill - Free Funnel when I do this?

Edited by 06SubLegTx
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