I picked up another Autozone tester, still have the O'Reilly one, and bought one from Harbor Freight. That makes four testers. Should I have tested more?
I only have four cylinders!
I recorded video of each gauge on each attempt, went back, and noted the PSI each time that I stopped cranking, but three of the gauges dropped to zero before I saw them.
The only obvious difference between my Autozone tester and the one that I can still return is that the plastic face is pushed in. Does it make a difference? I am sure that it makes a difference that sometimes they never seemed tight. With each of them I hand-tightened and then tried five more times to tighten it further. From time to time the Autozone testers never tightened, I rotated it another fifty times and it was still loose. So, their data is garbage, but have it anyway! I do not have any idea why there are blank spaces. Have it anyway!
Cylinder |
Permanent loaner |
O'Reilly's |
Temporary loaner |
Harbor Freight |
1 |
84 |
85 |
50 |
105 |
2 |
80 |
79 |
25 |
109 |
3 |
80 |
85 |
20 |
102 |
4 |
124 |
99 |
0 |
110 |
I tried to make a graph of the data, but Excel disappeared twice before I got very far.
I also rented the combustion gas tester. The fluid turned green, but the tester jumped into my lap and peed on me when I reached for my phone to take a picture. I tried again, with the exact same results.
A novice might assume that the Harbor Freight gauge is the same one as the O'Reilly one, but that is ridiculous! The Harbor Freight one says "Pittsburgh" and the O'Reilly one says "Totally not Harbor Freight, I swear!"
The hoses are similar (far more flexible than the Autozone ones, which was nice), but the HF one was significantly longer--annoyingly so. Oh well.
The cases were different and Harbor Freight had far more adapters. Curiously, the permanent connector was the only one to not fit my engine. I put Lock-Tight on the connector so it did not twist off in my block.
The data suggests each tester but mine was in tight enough.