Volvo Penta — Compression test
Testing & diagnosis · engine
From a Volvo Penta service manual — check it applies to your exact model before use.
Browse Volvo Penta generators & specs →
Before you start
- Make sure area around unit injectors is clean before removing them.
Procedure
- Drain fuel system and remove rocker arm bridge and unit injectors.
- Fit all 6 adapters 9998248 in cylinder head.
- Oil valve yokes, camshaft cams and rocker arm bridge.
- Tighten rocker arm bridge bolts per tightening diagram.
- Check valve clearance of all valves.
- Connect switch to starter motor.
- Connect compression tester 9988539 to first cylinder and perform test.
- Turn engine until tester needle stops and note reading.
- Repeat test on other cylinders.
- Refit unit injectors and rocker arm bridge.
- Adjust valve clearances and unit injectors.
- Perform leakage and functionality checks.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Source: Volvo Penta service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.