Toyota Avanza 1.3J Compression Test Specs TOYOTA

For your 2010 Toyota Avanza 1.3J model, the compression pressure specs typically range around 140 to 180 psi per cylinder. Slight variations between cylinders can be normal, but ideally, differences shouldn't exceed about 10-15% of the highest reading.

Looking at your dry compression test results:
- Cylinder 1: 160 psi
- Cylinder 2: 130 psi
- Cylinder 3: 130 psi
- Cylinder 4: 180 psi

Cylinders 2 and 3 are a bit on the low side compared to 1 and 4, with about a 27% difference between 3 and 4 (50 psi difference). This could indicate wear, incomplete sealing from piston rings, valves, or cylinder head issues in those cylinders, which may contribute to engine roughness or vibration.

Since the engine was repaired after overheating with piston rings and head gasket replaced, it's possible those cylinders may need further attention, like valve adjustments or rechecking the machine work quality on the block/refacing.

Your engine shaking and increased vibration may be related to uneven compression causing imbalance or misfires on affected cylinders.

Advice:
- Perform a wet compression test by adding a few drops of oil into the low-pressure cylinders and retesting—if pressure improves significantly, piston rings could be the issue.
- Double-check valve clearances and ignition timing.
- Inspect spark plugs for fouling or uneven wear.
- If problems persist, retake compression after more in-depth inspection to detect leaks.

The compression values are borderline low on 2 and 3 cylinders for a rebuilt engine, so further diagnosis is worthwhile.

Hope this helps get you pointed in the right direction for a smooth-running Avanza!