Glenn - I’m with you, just want to protect my investment. It’s difficult to be absolute as to what these numbers mean in isolation but I suspect it is an indicator that something is fizzing away somewhere. Les’s numbers would have been interesting.
Coolant quality is important, age, contamination and pH value matter. One thing I did do on the last rad swap was to really flush the old muck out of the block. Stuck the hose in and left it running for ages. Also the with 50/50 coolant mix I used distilled water rather than tap water in an attempt to get the numbers down.
