WM 1001IN Determining The Operating Cycle Of Cylinder 1 (Except Cayenne Diesel, Cayenne GTS Tip "PORSCHE Design Edition 3"): Information: Notes

WARNING: This page is about a different car, the 2010 Porsche Cayenne, 2009 Porsche Cayenne, and 2008 Porsche Cayenne. However, it is still accessible from the selected car via links, so may be relevant.

Determining the operating cycle of cylinder 1 with the "cylinder pipe" dead centre finder.

NOTE: Danger of timing chain jumping out of position

Risk of engine damage

→ Never turn the engine at the crankshaft without a chain tensioner.

→ Never turn the crankshaft against the direction of rotation.

→ Always counter the sprockets when performing assembly work on them.

→ Make sure that nobody starts the engine or pushes the vehicle while in gear when the chain tensioner is removed. To prevent this, stick a warning note on the steering wheel or ignition lock.

Information

An alternative method for determining the overlapping TDC is the "cylinder pipe" (dead centre finder). This tool is part of the pressure-loss tester WE 1066.

For some tasks, it is necessary to be familiar with the position of the piston in the cylinder (ignition TDC, overlapping TDC).

Ignition is off, ignition key is removed.

Remove spark plugs for the relevant cylinder. → Removing Spark Plugs

Fig 1: Removing V8 Spark Plugs
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Fig 2: Removing Spark Plugs Using Spark Plug Wrench - V6
Courtesy of PORSCHE CARS NORTH AMERICA, INC.
The dead centre finder or "cylinder pipe" consists of a glass tube (inspection glass) with a piston -1- , hose and a rubber cone -2- .

Fig 3: Identifying Dead Centre Finder - Cylinder Pipe
Courtesy of PORSCHE CARS NORTH AMERICA, INC.
The rubber taper is pressed onto the spark plug hole. The inspection glass is either held by an assistant or secured vertically using a magnet so that it is clearly visible.

Fig 4: Identifying Tool Setup - Dead Centre Finder
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If the engine is then turned in the direction of rotation on the crankshaft, the piston in the inspection glass is pressed upward in the compression cycle (top piston), and moves back down again immediately once the TDC has been reached. The piston remains down in the inspection glass in the overlapping TDC (bottom piston).

Fig 5: Identifying Engine Top Piston

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

Fig 6: Identifying Engine Bottom Piston

Courtesy of PORSCHE CARS NORTH AMERICA, INC.