Radiator flush?

SWAGES

MEMBER
2010 SUBARU FORESTER
2.5L
4 CYL
135,000 MILES

I've had exterior coolant leak head gasket issue for a little while now and it has moved into the combustion chamber so I'm getting exhaust into my coolant. I know this isn't the best idea, but I have no option, and this is my work vehicle but I'm flashing it to put in the Blue Devil head gasket sealant. I'm using a no spill funnel and every time I try to flush it the funnel starts filling up. Is this from my head gasket is this normal or is my thermostat stuck? When I simply was testing for the exhaust gases earlier my coolant level barely rose at all. Is it just now that I'm using plain water it's expanding more?

4 Replies

CANNON1349

MECHANIC
672 POSTS

Hello,

Typically, when filling a vehicle with coolant / water that has been drained, I have to fill it up, and squeeze the hoses to burp any air. The thermostat will be closed because the engine is not running and therefore it will not reach the predetermined temperature to open up. So, you may want to fill it and start the car to fill it some more after the water pump does its job. I apologize if I don't understand your question exactly, but I think I have an idea of what you meant.

Let us know,
William

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Friday, July 12th, 2024 AT 7:11 PM

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

I suspect one of two things may be happening. First, make sure there is enough room in the radiator to add the product.

On the other hand, it is possible that the exhaust gases are getting into the system and causing this to happen.

I feel funny asking this but since I'm not there, I need to. When you are filling, is there enough room to continue adding? Also, when it starts coming back through the funnel, is it foamy?

Joe

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Friday, July 12th, 2024 AT 7:27 PM

SWAGES

MEMBER
4 POSTS

No foam, and I was filling it definitely overcapacity because I was using a no-spill funnel and having extra sit inside the funnel. I had it overfilled in the funnel back 500 ml and almost within 5 minutes it would fill the final completely up which goes to 2,500 ml.

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Saturday, July 13th, 2024 AT 6:13 AM

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

There is expansion when the coolant gets hot. Could that have been what is happening?

https://www.2carpros.com/articles/coolant-flush-and-refill-all-cars

Let me know.

Joe

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Sunday, July 14th, 2024 AT 7:12 PM