A4 2.0TDi B7 - Limp Mode


Registered User
There's quite a lot within the posts, online too, about the Limp Mode which mine is still suffering with.

The symptons are - apart from the damn Glow Plug dash light coming on:

1. intermittent sluggish feeling whilst driving, with no acceleration. If accelerator is used the Glow Plug dash light comes on. One day it's fine but next day it could revert back.
2. when the Glow Plug light comes on it goes into Limp Home Mode which can be reset by turning the ignition off & on. This might be required 3 or 4 times on a 20ml journey.
3. seems to be drinking fuel, approx 15% less mileage per tank.
4. drinking a little oil and requires a top-up (1 litre) between services.
5. pressure within the rockerbox, causing mist .

Had the VAG code read as 000665 (or was it 000655, dunno) and consequently had the Diverter Valve changed as advised by the garage. The car felt ok just after it was done, but after a week or so it reverted to usual symptons.

There's a lot of talk about the PCV (Positive Crankcase Pressure Valve), or CCV, being at fault but don't know what it looks like or where it lives. Is this the culprit?

Can anyone help with the above, even a picture of what the PSV looks like and/or where it's located would be good?