Ok, Ive documented my troubles in my other Cooling Issue thread, now that the culprit has been discovered for that problem and since I had already bought the block tester I decided to perform this test today just to verify for my own curiosity. I drove the truck to work today and upon returning home i performed the test. While the fluid did not turn bright green like in the demo photo, it did turn a greenish color. See for comparison...






At first I was like ohhh dammnnnn.... but then i was thinking that since I do have cracked injector cups and there is diesel in the coolant.... wouldnt this give the results as seen? I mean one of the exhaust gases it could be testing for is unburnt fuel, and with diesel already in the system, it would detect that presence. Then if thats the case, the only true test would be to test it again after all the injector cup work has been performed. Then if it tests positive again, head problems are present. But damn, the whole point was to determine that before I do all the work. Not to do double the work after the first round is complete. Also, when i first did the test I did not allow enough air head space and sucked some coolant up into the tester. I emptied and dried with clean paper towels. Could this have contaminated the results. Should I wash and air dry the tester and try again? Ive never used one of these and I seem to be flush with brain farts these days. Any assistance or comments are appreciated.

 

It tests for carbon dioxide. That looks like a positive test to me . . .