To check the health of your engine you can measure your engines compression. This should be done with a minimum oil temperature of 30 degrees. The following values can help to determine your engines health:
| Type of engine | Engine code | New | Minimum | Max difference between cylinders |
| Petrol 1.6 LBX | CT | 8.0 – 10.0 bar | 7.0 bar | 2.0 bar |
| Petrol 1.6 LBX | CZ | 6.0 – 8.0 bar | 5.0 bar | 2.0 bar |
| Petrol 2.0 LBX | CU CV | 6.0 – 9.5 bar | 5.0 bar | 3.0 bar |
| Petrol 1.9 WBX | DG DF DH GW SP | 10.0 – 13.0 bar | 8.0 bar | 3.0 bar |
| Petrol 2.1 WBX | MV SR | 10.0 – 13.0 bar | 8.0 bar | 3.0 bar |
| 1.6 and 1.7 diesel | CS KY JX | 34.0 bar | 26.0 bar | 5.0 bar |
How to check compression on T2 and T3 engines
Get yourself a simple compression tester for petrol or diesel (available for both 1 cylinder at a time as for multiple at a time) and a socket / wrench to take out your sparkplug (petrol) or injector (diesel). Screw the compression tester in place. On petrol engines disconnect the coil so you won’t get zapped by the sparkplug. Then start turning over the engine by trying to ‘start’ the engine. Let it turn over until your compression tester needle stays at an even point. Then you know your compression.
This video shows how to do it on a VW engine: