jdblood202

Well, just ran a compression test, car is a 2003 AP1, 102k miles. Seems to have no problems, runs great for me. Here are the compression test numbers:

Cylinder #1: 170
Cylinder #2: 165
Cylinder #3: 170
Cylinder #4: 170

So, I did the test three times, the car was warmed up, I did the test right after I drove home from work, about a 30 min drive. The results were incredibly consistent. As you can see though, also incredibly low. I'm a little concerned that they're so low, I'm seeing the norm at least around 200-210, is there something incredibly wrong I could be missing?

mugen_rsx09

Have you done a wet compression test to compare numbers?

jdblood202

Wet compression test?

mugen_rsx09

Yes, a tablespoon of oil is poured into the cylinder though the sparkplug hole before checking the compression. Your numbers should go up.

jdblood202

Alright, I'll give that a shot.

mugen_rsx09

If the test come to 40 PSI or more, the trouble is poor rings.

jdblood202

Actually, I'm just going to re-do the entire test. I have the stupid ass harbor freight compression tester and the results I pulled from searching have lead me to believe it's the tester and not my car. I'm going to AutoZone to rent one, I'll re-post the numbers after the new test.

jdblood202

Alright, test number 2:

Cylinder #1: 240
Cylinder #2: 220
Cylinder #3: 215
Cylinder #4: 220

Again, 2003 AP1 with 102k miles, I'm a little worried with cylinder 1 being so high compared to the rest, what does that indicate/what do I need to test for next? Car was fully warm, all 4 spark plugs were pulled for the test, went back to re-check cylinder 1 after cylinder 4 to verify and it still read 240. Thanks guys, I appreciate all of your help! Also, Harbor Freight compression tester=absolute garbage!

superchargedk20

Harbor freight is just cheap supplies. U still got consistency just at a lower rate. Ur harbor freight test was actually more consistent compared to ur auto zone test

jdblood202

Yea I know, that is what's tripping me out. Minus cylinder 1, the AutoZone test, OEM brand, was consistent. On the harbor freight tester it read lower compression, but consistent across the board. When I did these tests I cycled through at least three times to verify accuracy and consistency. Am I overthinking this and my motor is fine? Or do I need to address the issue in cylinder 1? I know if a cylinder was significantly lower than the rest I'd perform a leak down test. What if it's significantly higher? Sorry for the barrage of questions, just trying to expand my garage mechanic hobby knowledge.