Block Tester BT-500 Combustion Leak Test Kit
Complete Combustion Leak Test Kit, Leak Tests, Bt 500 Combustion Leak Test Kit
What We Like
- Ideal to detect the presence of exhaust gases in an engine's cooling system
- The kit comes complete with enough fluid to conduct up to 16 tests
- Large and single-chamber design provides greater accuracy and uses less test fluid
Disadvantages
- The one-way valve at the bottom of the test vessel may leak
Results of our analysis:
We analyzed 9,350 reviews for 46 products in the Air Conditioning Leak Detection Tools category.
We then analyzed 82 reviews for this product. Of these, 19 reviews were recent.
100% of reviews were positive.
Final Score:

9.76 out of 10, based on these factors:
Common Questions
Is it possible to use this to diagnose an exhaust leak?
If you're trying to determine whether or not an underhood exhaust leak is coming from, the tool might be useful. It will detect exhaust gases, but it won't be able to tell you where the leak is coming from.
Does tester fluid leak into coolent while testing?
If you want to rinse the top cap with water, you can use distilled water or pop it off.
Is it possible to use it for a diesel fuel engine?
It works on diesel engines, but a positive test might show a greenish-yellow color to the fluid rather than the full transition to yellow that you'd see when testing a gasoline engine with a combustion leak.
Does the engine have to be running to work or can we turn it over and over to test?
If there is no combustion, the block tester will not work. I would say, if it is in the process of cranking the fuel in all cylinders while cranking, but will not remain running, it may bleed enough carbons into the coolant system.
Does the negative results mean that the block tester doesn't create an air-tight seal on my honda civic?
I think it's too large and doesn't fit into the radiator, so I'm guessing it won't make an air tight seal.