Confusing 2.7L leakdown test results
Could use your help making sense of my leakdown test on my 2.7L.
2001 Tacoma Prerunner, 2.7L 3RZ-FE, 215k miles, auto trans, has run well until recently. Valves have never been adjusted to my knowledge (I've had the truck since 150k and haven't done them and I'm 99% sure they weren't done before that. I know, not good.
Truck has been running a bit rough lately, pending code initially was Cylinder 4 misfire. I swapped in a new plug, didn't get better, swapped the coil pack from Cylinder 1 and the pending code has now shifted to Random/Multiple misfire. Decided to do a leakdown test and the results are puzzling to say the least.
I ran a leakdown test on all 4 cylinders, 3 times each (because I assumed based on the numbers that I was doing something wrong), but all the % losses were +/- 3% each time. I have the OTC leakdown tester. So,
Cylinder 1: 22-24% loss, mostly hearing loss from the oil filler and/or throttle body vacuum port on top of the valve cover. I assume this is air getting past the rings, if there is another reason, I'd like to know.
Cylinder 2: 54-56% loss, again loss is coming from oil filler and/or throttle body vacuum port. This truck doesn't burn any significant amount of oil (maybe 1/4 to 1/2 quart low from full at the oil change which I do at 4k miles), no smoke out the exhaust on start up, hard acceleration, or heavy load. This result makes very little sense to me. Again, I ran the leakdown test on this cylinder (and the other 3 cylinders) 3 separate times.
Cylinder 3: 43-44% loss, same as above, but I can also hear loss from the intake.
Cylinder 4: 10-13% loss. This was the cylinder that originally threw the misfire. This also doesn't make much sense.
Also, no bubbles in the coolant during any of the tests. So, what gives? I'm hoping it's something obvious and I'm just an idiot. Thanks for your help, I appreciate it.