VAG Com Reading for timing belt

[dodge88]

Hi all,

My B6 2.0TDI Estate 98k miles full service history has a problem....

When idling the engine rocks and judders physically making the car move - not only this but the exhaust fumes are horrendous they make your eyes water.

When using VAG com i have found "Torsion Value" is at +2.97 (Vag recommends -1.5 to +1.5 when idling)

Is my timing advanced and causing an over-fuel?

[DMitch16]

No as fuelling is controlled by the ECU not the valve timing which only determines when the engine "inhales" intakes air and "exhales" expells exhaust.

[martin1810]

You are wasting your time looking at the torsion value. To check the timing you need to use the correct locking tools and look to see that everything lines up properly. VCDS can't do this for you.

[Abduls Miezis]

Hi all,

My B6 2.0TDI Estate 98k miles full service history has a problem....

When idling the engine rocks and judders physically making the car move - not only this but the exhaust fumes are horrendous they make your eyes water.

When using VAG com i have found "Torsion Value" is at +2.97 (Vag recommends -1.5 to +1.5 when idling)

Is my timing advanced and causing an over-fuel?

You have to retard timing. This is common after timing belt change. Most "specialists" just use locking pins and assume everything is ok, but something like 4 degree of mistake any way (advanced ot retarded) is common. Always after something is done with timing belt torsion must be checked and adjusted. Some cars run well with 3 or 4 degree of misalignment, but most will have problems you described. In most cases they run fine when warm, but may shudder when cold.

[DMitch16]

There is no misalignment as such and the "Holy Grail" of a 0.0 to 0.5 Torsion value completely unsuitable for a vast amount of PD engines. Whilst it may have been optimum from the factory once an engine has a decent amount of miles on it and seals, engine parts etc. have expanded, contracted, bedded in together and so forth the best Torsion value is the one where you find your engine runs well hot or cold and starts first time in any weather. There are so many other factors involved that Torsion should not be the be all and end all of why an engine doesn't run well. It may help to have it closer to 0.0 - 0.5 for some but I have seen engines struggle at those settings and purr with what would be considered a "misalignment" setting of 4 or even -4. Mine ran superbly at +3.72° for over 75000 miles and still runs well at +1.49° after a belt change at 190k. I do clean the EGR and pipework every 50k and the inlet manifold at 100k (due soon). I have also renewed valve stem seals and cleaned injector nozzles which had a crusty coating covering some of the spray holes which helps with idling no end.

The best setting is the one that is right for YOUR engine and it doesn't hurt to play with the cam adjustment as long as you know what you are doing or understand what the small changes actually do.

[Abduls Miezis]

Exacly, but if torsion is so much off from factory setting its first thing to start with. Thats what owner of the car wants here to start with cheap and easy fix thats propably is the blame. If that doesnt work he will have to move forward with probably more expensive and time consuming things.

[DMitch16]

Exacly, but if torsion is so much off from factory setting its first thing to start with. Thats what owner of the car wants here to start with cheap and easy fix thats propably is the blame. If that doesnt work he will have to move forward with probably more expensive and time consuming things.

Good ethical approach - a lot of places would just replace, replace, replace until "fixed" which is expensive (or customer says "No more thank you!" when invoice gets too high).

Also if DPF fitted check Carbon Mass Index (group 068 on VCDS engine measuring blocks) which is the accumulated ash reading as a full or nearly full DPF can cause the engine to run erratically. If DPF filter element deleted (removed and can welded back up) this also can cause bad running and stinging gases to be produced. Fix is usually replace DPF with new or refurbished clean unit and remap back to factory settings.