My car went in for a service last week obviously had an oil change, but since I've got it back it's been reading my oil is ¾ full, over the last 12 months its read full from the last service. I've taken it back to the garage and the mechanic says he's 100% put 6.9L like it takes so doesn't want to put more in suggesting it might be a faulty sensor as there isn't a leak. Anyone had any experience of this? It's a 3.0 tdi 

Probably a faulty level sensor if he guarantees he put the correct quantity in, but why should it suddenly start reading low?? 
Kind regards,

Gareth. 

I'm not convinced they've added the right amount of oil, it reads ⅔ but then a little bit more a few mins later when settled, I wish they kept the dipstick option instead of complicating things.  I'm gonna do it again tomorrow and see where it's at and I'm very tempted to add a little more to see if it goes up, I think I'd have to drop the oil to change a new sensor by the looks of it.

Edited August 12, 20241 yr by Brammers69

Hello Kristian, 

There is really only one way to establish whether it is quantity or sensor associated. 
Simply drain the oil yourself, and carefully refill with the exact measured quantity of oil ( quoted capacity without filter). 
If you add oil to satisfy the oil level indicator, then you will never know whether it is overfilled or not.

If you can only find a quoted capacity inc. filter, then you will obviously need to renew that as well. 
Yes expensive, but you will then have peace of mind. 
Kind regards,

Gareth. 

Adding surplus oil is not without risk. Better to establish whether the sensor is faulty than to take a chance by over-filling. As Magnet suggested, the only way to be certain is to remove and measure the qualtity of oil.

This is down to a leaking sump plug which I've opened up a new topic about, the sump plug hole has 2 indentations that I've been told shouldn't be there so been quoted a new sump bottom pan, but on research it looks like all it needs is some sort of crush plug. Any ideas anyone?? 

Thanks for your input gents.