After a couple failed attempts at doing a compression test using borrowed gauges from AutoZone (the hoses kept popping off at the spark plug end), I went and bought my own gauge and did a compression test on my car a few days ago. My results were:

cyl 1 - 205 ok?
cyl 2 - 185 bad?
cyl 3 - 215 good
cyl 4 - 215 good

Because of the lower results from cyl 1 and 2, I want to try doing a leak-down test on those cylinders to find out where I'm losing compression.

Since I don't really need to measure precisely how much pressure I'm losing (I just want to locate where it is being lost) I was thinking I don't need to get a leak-down test gauge. I could just pressurize the cylinder and listen for air leaks.

Can this be done using an air carry tank filled at a service station air pump? Could it be done using a 12V tire inflator? Would these provide sufficient air flow and pressure to determine all possible leak paths?

if you have a small tank but can put out 90psi then yeah it's possible. I dont think you have anything to worry about with those numbers though. Looks borderline questionable to me. As long as you can get a hose threaded into the spark plug whole and adapt it to the tank then it can be done. Listen for were the leak is coming out of. $10 sais it's coming from the oil fill cap.

I bought a 7 gal air carry tank at Walmart along with some quick connect fittings. I also ordered a 12V 300psi tire inflator and a KD air hold extension hose from Amazon. The hose arrived but still waiting on the tire inflator. I think I could use the hose from my compression gauge but it has a schrader valve in one end and I didn't want to mess with it.

This afternoon, I tried filling the tank at a service station but the air pump topped at 80psi and the shop was closed so I couldn't get it filled any higher. The tank capacity is 125psi. I'll either try the service station tomorrow or wait for the tire inflator to come in.











If I am getting blowby past the rings, wouldn't I be burning large amounts of oil? My oil level is okay and no black smoke out of the tailpipe.