testing coolant mix
 

When you test your glycol/water mix, do you draw your sample from the reservoir or drain some from the block?

On a normal car I would take my sample directly from the radiator to ensure that I am testing the fluid that is actually circulating through the system. In this case, I have not added anything to the reservoir in the last year so I am reasonably confident that the mix in the reservoir is the same as that in the system.

The dealer tested it for me last fall when the car was in there on an unrelated issue and it was good then so there is probably no reason for it not to be good now, again because nothing has been added. It's still green and clean.

But, I learned the hard way many years ago to never assume my coolant mix is good prior to winter lay-up. Fortunately, the block I cracked was a dime-a-dozen Chevy small block. So much for the frost plugs doing their job.

remove cap and test there. by the way they are casting cleanout plugs not freeze plugs

Thanks Ex!