3.0 tdi hunting overrun

[jubbly]

No it's on the list, finances don't allow any progress on this at the moment.

[Cwizard]

The best thing to do is oil + filter change on the gearbox. Try to get the cheapest option with genuine oil from an indie as it might not do anything to your gearbox just smooth it out a bit. Then after few months back to same old. Just like happened to me. They suggest $4000 bill to fix with new mechatronics unit. Otherwise it could lead to a total death of the tranny.

[TheMatador]

Otherwise it could lead to a total death of the tranny.

What! Who said that and what breaks?? Have you replaced your mechatronics unit? A whole new gearbox must be about the same price?

[Cwizard]

What! Who said that and what breaks?? Have you replaced your mechatronics unit? A whole new gearbox must be about the same price?

I've read a report on that specific issue for ZF 6 speed found in the Audi A6. Only cure if the oil change doesn't work is new mechatronics unit. It will most likely lead to tranny completely destroyed. I got a quote for new tranny about $10,000 brand new or about $4000 for mechatronics only which would save it from destruction.

[TheMatador]

Don't suppose you've got a copy of the report have you (or a link to it)?? This is pretty serious. Mine has been doing this gentle sort of pulsing on the overrun ever since I got it at 80k miles and I'm now nearly at 120k. I spoke with a ZF engineer a couple of years ago and he said the "Lifetime" fill is about 120k kms so I'm probably due a fluid change.

[Cj89]

I know this is a huge thread revival- however I have the exact same problem as Jubbly - did this ever get resolved?

[jubbly]

Nope I sold the car years ago.

[Cj89]

Ok, well - I have the same car, with the same problem and the same DTC of driver side engine mount (and 5 out of 6 glowplugs need doing, but the car starts perfectly)

I cant clear the DTC untill I replace the engine mount however I doubt it is the engine mount because it has had that DTC for the last 30k miles with no problems.

The steering rack has had a bit of a leak so whilst I had the car in the air to get that out and refurbished I had a quick inspection:

The front ‘snub mount’ was a little perished, so I ordered and fitted a new one.

This didnt fix the problem.

It definitely feels gearbox related - seeing as though when coasting in neutral my idle is solid too.

There is also a judder/shudder when in a high gear and engine is low revs but accelerating (4th gear around 1200rpm) almost like clutch judder.

I wonder if it’s a torque converter problem.

I have ordered a gearbox service kit - when that arrives, I will change the ‘oil strainer’ in the gearbox and fill with new oil and report back.

Cheers

[Cj89]

A Quick update,

Before changing the gearbox oil - I used a product by lubegard called instant shudder fixx - this helped the shudder a lot... This indicated that part of the problem was fluid related and not mechanical

The hunting on overrun was still there but not as prominent.

So I changed the gearbox oil and changed the gearbox filter. Whilst filling up with new fluid, I added more Lubegard Instant Shudder Fixx and also some of their red bottled "ATF Protectant"

This cured the shudder altogether! The hunting on the overrun is still there but only so very very faint, and I have learnt that the only hill I can get it to replicate on, doesn't bother me that much now.

Hope this helps anyone with the same problems