Combustion Gas Leak Test

[Rob11010]

2010: Sudden drop in coolant level in overflow tank so I tried running a combustion gas leak test @ radiator. Removed some coolant but it continued to rise making the test a pain to run. Saw others run from overflow tank and thus I tried the same. As I received a negative result I am questioning the ability to run the test from the overflow tank. Anyone have any positives running this way?
I also noted air bubbles from the coolant when I was trying to run the test from the radiator. Any potential cause outside of a head gasket?

 

[John P.]

I would get one of those flush and fill kits that come with the cap that has a neck for a funnel on it and try testing from the higher up neck part maybe. Are you experiencing any overheating? Wet floor? Really need some more information.

 

[Rob11010]

I would get one of those flush and fill kits that come with the cap that has a neck for a funnel on it and try testing from the higher up neck part maybe. Are you experiencing any overheating? Wet floor? Really need some more information.

Thanks for the advice. Re-ran the test a few times after removing more coolant. Still negative. No overheating, no heater core or other leak, and coolant level has been steady ever since. Saw the coolant level drop (overflow empty) only once. Only thing I can think of is I did have the car up on ramps prior to this. Previous owner did a water pump just before I bought 6 months ago. Perhaps air in the system and ramp incline "vented" it? Seeing nothing in the overflow tank and air bubbles in the radiator freaked my out but I would think a combustion gas leak test would pick this up. Also just changed the oil and no milkiness noted so I am hoping head gasket is fine and I am just paranoid.

 

[malibuz16]

Remove this plug to bleed any trapped air.

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