Coolant flush turned brown (bad head gasket?)

Oct 11, 2014
I am trying to revive my 86. I finally got it to a point where I can start the engine, so I went to try and flush the cooling system. Here’s the problem, I put 4 gallons of distilled water and a coolant flush bottle. Ran the engine for a few minutes ( high rpm’s maybe 1500 bc I am trying to tune my carb at the same time). Check the radiator and the water is brown overfilling out the funnel. I was an idiot and let it continue for maybe another minute. Did I blow my head gasket or is this common for an old cooling system and just had air in it?

I didn’t have temp sensor hooked up bc the wire was frayed. I ended up splicing it last night anyways even though there’s a possibility the head gasket is blown

I plan on getting a test kit but wanted to come here in the meantime. Any help?




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Jan 5, 2015
Looks like a really dirty coolant system to me, Keep flushing it till its clear.
Every few years I disconnect all the large radiator hoses and open all the drain valves and put a garden hose in my system, I hose it out until it looks clear.

If your worried about a HG you coolant would be bubbling air and your dipstick would show either a really high level or chocolate milk.

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