3.0tdi fuel consumption dropped significantly - no fault codes

**grasshopper** · 27-02-2021,01:14 PM

Hi All

The fuel consumption has dropped significantly on my 2012 3.0tdi A6 Avant.

Ive just got back from my garage who scanned it using his snap on unit.

The only thing that looks amis is:

'coolant temperature at radiator outlet' is showing 15.4 degrees C

The line underneath is:

'coolant temperature at radiator outlet - SPEC' and this is showing 93.5 degrees C

Couple of questions:

1. Is the 'coolant temperature at radiator outlet - SPEC' the expected value?

2. If the 'coolant temperature at radiator outlet' is low (15.4 degrees) would this cause the ECU to over fuel?

The coolant reservoir is certainly a lot warmer than 15 degrees so I can only presume this sensor is reading incorrectly....?

Thanks

**Olio** · 27-02-2021,03:55 PM

What is your reference? When was that over? Last 2-3 weeks were really bad for fuel efficiency due to low temps.

**grasshopper** · 27-02-2021,04:23 PM

Originally Posted by Olio

What is your reference? When was that over? Last 2-3 weeks were really bad for fuel efficiency due to low temps.

This has happened steadily since about September last year.

When I used to fill the tank it would give me a range of 590-610 miles, this has steadily dropped to 460miles range now.

In reality, I was getting 560ish miles a tank, Im now getting 390 miles before the fill warning comes on.

Ive tried supermarket fuel, shell fuel, shell super diesel stuff and it doesn't make any difference.

Theres definitely something wrong...

**Olio** · 27-02-2021,04:43 PM

Yes, it seems you're right. About the coolant temp, I read them like you. Expected temp 90+, read 15+

Maybe a sensor issue, or an air bubble in the system? (Cf Coolant temperature actual V specified value | Ross-Tech Forums )

The 3.0 TDI avant is the car I should have bought I i had known better then

**grasshopper** · 27-02-2021,05:40 PM

Has anyone else any thoughts?

Or any experience of the snap on diagnostic unit?

Is the SPEC value the expected value?

**grasshopper** · 27-02-2021,07:49 PM

Can anyone assist me in the part number for the radiator outlet sensor? I’m going round in circles searching for it and it’s interrupting my Saturday night beers 😬

Thanks

**Elansear** · 27-02-2021,09:08 PM

This may assist.
Audi Parts catalog - ETKA Online, Audi EUROPA, original Catalog Audi EUROPA

**grasshopper** · 27-02-2021,09:34 PM

Thanks

**grasshopper** · 01-03-2021,09:36 AM

Is the radiator outlet sensor 06A 919 501 A

Or is this the sender to the dash board?

Nothings ever clear or easy is it?

**morski** · 01-03-2021,10:54 AM

Thats the one. £46.80. Same one used across a lot of models. Interior temp sensor is on the dashboard and air temp sensor for engine management is on the front bumper bar