After replaced engine on our 2011 Prius (230,000 miles), just to make sure the engine we bought was fine, I purchased a quick leaking test. Did the test and no bubbles and no color change. Did the test as well in our 2013 Prius (105,000 miles)but this time there was bubbles, but the color didn't change too. The test only mentions the change of color as indication of head gasket failure but nothing about bubbles or no bubbles. I repeated the test on the 2011 to make sure it was sealing completely the deposit, but again no bubbles or color change in fact I believe some kind of suction was there because when disconnected the cap I hear a pop sound. Any thoughts? Any idea why one has bubbles and not the other? Maybe I need to do something on any of them.
Was there any difference in how you ran the test between the 2011 and 2013, say in how cold the engine was when you started or how warm you let it get?
Both in maintenance mode, and monitored temperature on app until 180f reached, and waited 10 more minutes. Could see coolant moving inside deposit from upper hose.
The info on the product on Amazon says it is normal to have bubbles present. It's the color change that indicates the presence of CO2 and a bad head gasket. SM-G781V ?
From the description and pictures on the product packaging, it would appear that you overfilled the test chamber/apparatus. Overfilling the fluid would make the test less sensitive because you would have more buffer in the solution for the CO2 to overcome to make the color change. I'd guess you have about twice the called for volume that is required. Try repeating the test using less indicator fluid in the apparatus. It also says to slightly rev the engine as well. That could make any leakage more pronounced. SM-G781V ?
Apparently, CO2 leaking into the coolant will bubble through the test system and acidify the test liquid, causing an indicator (pH) to change colors. SM-G781V ?