Compression Pressure, Checking: Procedure
WARNING: This page is about a different car, the 2015 Audi A7 Quattro and 2014 Audi A7 Quattro. However, it is still accessible from the selected car via links, so may be relevant.
- Engine oil temperature approximately 80°C (176°F)
- Battery voltage minimum 12.5 V.
-- Remove the engine cover, refer to ENGINE COVER, REMOVING AND INSTALLING .
-- Disconnect the connectors on all of the glow plugs.
-- Disconnect the connector -arrow- on the Fuel Pressure Regulator Valve -N276- from the cylinder bank 1 (right) fuel rail.
-- In order to reduce the fuel pressure in the fuel rail, start the engine briefly.
-- Remove all the glow plugs, refer to GLOW PLUG, REMOVING AND INSTALLING .
-- Install the Compression Tester Kit - Adapter 8 VAG 1763/8 in place of the glow plugs and connect the Compression Tester Kit VAG 1763.
NOTE:
For information on using the tester, refer to the Operating Instructions.
-- Have a second technician operate the starter until the test stops showing an increase in pressure.
-- Repeat procedure on each cylinder.
| Compression Pressure | Vehicles with a Turbocharger |
|---|---|
| Bar Pressure | |
| New | 28 to 33 bar (406 to 478 psi) |
| Wear limit | 21 bar (305 psi) |
| Maximum difference between cylinders | 5 bar (72.5 psi) |