If you find yourself needing to do a leakdown test yet can't find a shop to do it let alone one that knows what it is you can easily do it yourself at home if you have the proper compressor and compression tester gauge.

1. Take the small valve at the end of the hose on the compression tester out, it should have a little tool to unscrew it. This way air can go out without the valve stopping it.

2. Make sure the engine is at TDC for either cyl 1-4 or 2-3 and take all spark plugs out.

3. Now thread the compression tester onto one of the cylinder that are at TDC and pop off the gauge.

4. Now comes the compressor, most compressors have a dial to adjust the pressure from 0-125psi or so. Turn it to 0 and hook the hose up to the compression tester hose. When all is hooked up slowly increase the pressure to about 30-40psi and listen for air leaks, too much pressure and the engine will crank over since the plugs are out.

Air in the exhaust means exhaust valves (my car's problem), intake hose or sound in the upper ic pipe means intake valves. Lots of air coming out of the oil caps means rings and bubbling in the coolant means headgasket.

5. Redo above steps on other cylinder at TDC, then check other cylinders once you have them at TDC. Once all are done you should have found what your problem is.


Note: your compressor or tester may be different from what I used and may not work or may give different results. This is not a true leak down test but will give you similar results as it will tell you where you are losing your compression. This worked very well for me and was 100% accurate with diagnosing my low compression..bent exhaust valves.