a4 2.5 tdi timing anything to worry about?

[a4driver]

noticed that the car sometimes sounds a little rough when just started/idling, bit like its pinking but then engine noise changes and it goes, then can come back. been like this for a few months

MPG seems ok ~30 for town driving and 45+ for motorway @70mph

ive just checked the timing with vag-com (engine temp 86oC) basic settings and im seeing the timing is "late" 2.6ATDC but after a few moments it will retard to +14 early and the "pinking" rough noise from engine comes then a few moments later it will go to "late" 2.6 again with the rough noise gone.

is this usual? when the timing is not on basic then it holds steady at ~2.4-6 which is within the spec.

Cheers
Mike

[Crasher]

It needs setting up which you should relay start by locking the crank with a locking pin and locking both cams with the setting plates so that the valve timing can be checked and adjusted if necessary. If this is correct, then the Commencement Of Injection (COI) can be set which is done in Basic Settings 04 and this is only available of registered versions of VAG-COM which also have a graphical TDI timing checker function.

1) Start the engine
2) Go into Measuring Blocks 08, Display group 007 with the engine running at idling speed.
3) Check the readout in display zone 4 (coolant temperature). Specification: at least 85 °C

Do not continue with the test until the coolant has reached the specified temperature.

4) Start basic setting function, Display group 04, engine running at idling speed.
5) Check display in display zone 4. Specification: 100%
6) Observe display in display zone 2. Specification: “retarded”
7) Check display in display zone 3. Specification: 2° ATDC ± 2°

If the readout does not match the specification, adjust the commencement of injection (injection timing).