2010 Prius Blown Headgasket

electrontechnik - How many times, and at what mileage, in 192,000 miles did you change the engine coolant?

 

Coolant deteriorates, becomes acidic and dissolves cylinder head gaskets. Not changing engine coolant before it goes bad is a major cause of blown head gaskets.

The balls floating in your tester measure freeze protection, not PH. PH is measured with test strips that turn color to indicate numerical acidity. New coolant is typically 8 to 9. 7 is neutral. Below 7 is acidic.

 

electrontechnik - Thanks for the video. Conductivity testing is a good test but not an absolute indication of coolant PH because coolant with a good PH can be conductive due to a bad ground connection that causes current to flow through the cooling system and register on the meter.

Also, the video states that the meter reading for good coolant should be under 0.05 V (not 0.5V). The meter readings you show in the above pictures are 0.17 and 0.14 which are much higher than 0.05, indicating very bad coolant.

 

That's a relief. Hope everything goes well with the repair and your Prius is restored to good health. Good luck.

 

I hate it when someone tells you to do something, but not the reason for doing it. I learned a very specific reason in this thread, for timely changing the coolant.

 

i've heard about it and have huge reservations. there are too many variables. type of metal in the meter electrode and engine, internal meter resistance, etc.

if one wants to pursue coolant testing, there are commercial testing strips, not cheap last time i checked. it's easier just to change coolant every 100,000 miles IMHO.

 

there are so many unknowns, i don't even know what 'clean looking coolant' means? it seems prudent to change it at factory recommended intervals. or more often if you intend to keep the car for several thousands of miles.

 

This means that if the coolant were poured into a glass and a few ice cubes added, you would not hesitate to drink it. (Of course, antifreeze is poisonous so this would be a very bad idea.)

With some vehicles, when the coolant is changed at the manufacturer-specified interval, the drained coolant contains debris and looks/smells nasty. This usually is not the case with the Prius.

In any event, I think the OP needs to change the coolant now, if it is the original fill - way past due.

 

You want to change the coolant before it goes bad. Bad coolant allows corrosion which is what you want to prevent. Therefore, the coolant that comes out of the engine when it is changed should look just like the coolant you put in, if not you waited too long to change the coolant.

 

can it be bad, even if it looks good?

 

And this is why I got my coolant changed at the dealer last week for $100. Honestly I'm super cheap, but is having to rebuild your engine worth it? I feel really good about spending that money, honestly. And I NEVER go to the dealer (diy oil changes all the way!). Just look at it as insurance

 

How'd that go? They managed to avoid air pockets, did a decent job?

I do hope they drain the block as well; a few posters have mentioned they sometimes just drain the rad.

I did a civic coolant change recently: a blinking deluge came out of the block.

 

They did a complete engine coolant flush. They did a great job, no air in the system, also quick service and friendly people. My dad asked me if they pushed other services on me, or tried to sell me stuff I didn't need, I said "nope! You can't sale any services to a car with 260,000 that is in perfect mechanical condition!" The worst thing about my car is my paint!

 

What did the drained coolant look like? Per your post #30, did you use pH strips on the drained coolant?