The very first generations of Peugeot 207 GT/THP/RC/GTI engines have a serious problem.
Under unknown circumstances the engine might lose its timing because the timing chain sprocket can slip and change position.
This problem is usually found in engines produced between 2007 and early 2008.
How the problem starts
As shown in the picture above, the crankshaft timing chain sprocket (timing pinion) does not have a key or any other way of locking into a single position.
The only thing securing the timing pinion to the crankshaft is the pulley hub and bolt (Nr 9) .
If the bolt elongates, or the pinion slips then there is nothing to stop it. Once it does, it changes the
relative position of the camshafts to the crankshaft, altering engine timing.
Once the engine has lost timing, it will appear as the fuelling has gone lean throughout the whole revolutions range.
Both Short and Long term Fuel trims will start increasing, to the point that when long term fuel trim goes over +10%,
there will be a Fault code warning for "mixture too lean". The fault code can only be monitored with the manufacturer's original
diagnostic equipment, not by any OBD2 generic diagnostic tool.
OBD2 tools can only monitor the Fuel Trims, they are the only evidence of a malfunction.
If the timing is completely off, there will be severe problems with engine knocking and the ECU will start utilizing safe modes, turning off
the turbo and drastically increasing fuel consumption.
How to fix
To fix the problem the whole pulley hub,timing pinion and chain assembly needs to renewed with the latest parts from Peugeot.
Disassembling the pinion requires the use of a special engine timing tool for EP6-DT/DTS engines, shown in the next photo.
The engine timing can be checked using the timing set. In the following photo the engine has lost its timing and the timing set
will not lock into place..
Timing chain 0816H9
Timing tensioner 0829G3
Timing pinion 0513C8
Chain Guide 081830
Chain Guide 081831
Engine timing pad 081829
Pulley screw m14x74 0516L8
Screw with base 080677
Screw with base 080678
According to Peugeot's servicebox, newer parts have been designed and incorporated in newer engines, to stop the problem from appearing.
The engines which have had the pulley hub upgraded have never lost their timing again.
More information or answers in frequent questions you can find in the Forum of Technical Support of Etuners