Audi S4 2002 V6 2.5L TDi AKE - VCDS TDi timing

[Heilanpiper]

Hiya, I have zero experience on V6 Tdi 2.5L, in Canada / USA and I'm pretty sure this is the first car here as I brought it over from Germany. My son complained of a long crank on cold and I decided to hook up my VCDS (professional) to peer at the Tdi timing (basic settings group 004) and chose Tdi timing and it is way retarded but I noticed it cycled between base timing and it advanced to way advanced and kept cycling.

Never seen VCDS do this on any ALH / AHU engines that I've worked on. I'm pretty sure the long crank is due to the retarded Start of Injection and I have bought all the jigs to do the Timing Belts. Has anyone seen this cycling in VCDS Tdi timing?

Cheers!

[Crasher]

The cycling is correct, I would remove and fit new glow plugs. Testing the old ones before fitting new ones would be interesting to see if they are the cause but I strongly recommend you do not refit the old ones, they often snap which is depressing. Also getting the old ones out can be a sketch as they feel really tight, last year we had two cars where all six snapped. If you have a high enough rated ammeter, you can check they at least consume power without removing them bit it isn't a perfect test.

[Heilanpiper]

I alway flood the glow plug heads with 50% ATF and 50% Engine Oil - leave it for a week of driving and the glow plugs come out like hot knife through butter. There are two glow heads that aren't recessed. I have a set of Beru and so far have replaced one. The old one came out without a fight and it tested good.

TDi Timing Update - it was about 4 degrees retarded and I dialed it in to slightly advanced of mid line in TDI timing graph and the long crank went away. Need to ignore the cycling when it kicks it to 15 degrees advanced as it does it's cycle and returns to base timing. Thanks Crasher.


Now that long crank has gone away, I'm turning my attention to dialing IQ as it should have more jam on the low end torque. I'm definitely up to the challenges of supporting this rare car in North America.