A6 3.0 TDI Maintenance

[JimmyM531]

My 2014 A6 TDI is coming up on 125k miles. I have only done a few maintenance items since I took ownership of it at ~60k miles. Oil changes every 10k, fuel filter, air filters, and that’s about it. I’m wondering if there are some other preventative maintenance items I should be doing or considering doing in the near future?

[rkovacs]

Hopefully you have had the transmission fluid and filter changed. I just did mine over the weekend at 90K (just got the car). The manufacture of the transmissions give it a 50K service for fluid and filter.

[Kevin1]

My 2014 A6 TDI is coming up on 125k miles. I have only done a few maintenance items since I took ownership of it at ~60k miles. Oil changes every 10k, fuel filter, air filters, and that’s about it. I’m wondering if there are some other preventative maintenance items I should be doing or considering doing in the near future?

As set forth in my signature, I have taken two A6s from new to over 140k miles. Both became rather costly to maintain after they passed the 125k mile mark. In fact, my 2015 A6 TDI became so costly to maintain at the 125k mile mark that Audi decided to buy it back for $76,098.73 under the extended EPA Emissions Warranty (yes they paid me more for an 8 year old car than I paid for it when I bought it new). By the way, the car was dealer maintained from new, with additional oil changes every 5k miles and tranny/differential fluid every 50k miles. I wish I had better news for you.

[67ITB]

I have a 2014 A6 TDI Prestige. I have owned it since new. I have 248K miles on it now.
I have had the diesel gate scandal updates applied.

I still love driving the car its a comfortable, smooth, highway cruiser.

No performance mods, just some of the basic VAGCOM stuff like windows down with the remote and 1 or 2 others. I did add small the trunk mount spoiler.

The Good:
No major issues to speak of until recently.

I did a front wheel bearing around 145K.
Otherwise just routine service, fuel filters, brakes and tires. I had been religiously sticking to the Audi factory recommended services for oil changes and fuel filters...during the pandemic I started doing my own oil changes at 5K, and fuel filter at 10K.

I have never done glow plugs or injectors.

Embarrassed to say I haven’t done the transmission service others mentioned. I don’t have any excuses. I was using the dealer for all scheduled maintenance and they never mentioned it. Shame on me for not thinking of asking. But at this point I am not going to touch the transmission. It shifts smooth as the day I bought it.

The Bad:
I have a pretty significant coolant leak. 2 local independent service shops couldn’t diagnose, and 2 more wouldn’t even try to work on the car.

I am currently waiting on the dealer to get me in. I had an appointment for tomorrow (23 October) that I had made about 7 weeks ago… they called me Friday and canceled. Pushing me off to 24 November.
The car still runs great, tons of power, great MPG (Got 34.56 MPG at the pump today)

Searching different forums tells me it’s oil to water cooler buried deep under the intake manifold in the V of the engine… This is above my skill level. One Youtube video said it was a 12-15 hour job! That will suck at the dealer rate! But again I know my limitations on this car.

I also have a small oil leak. The car is not really using much oil between changes. Less then ½ a quart, probably closer to a ¼ of a quart.

After driving for a while and stopping at a light, or my destination I smell oil in the cabin. I do not smell it when the car is moving.
When I open the hood I can smell oil, but no visible smoke, and no tell tale signs of leaking that I can see from above using a flashlight, mirror and close eye.

I have replaced a window switch, and had a taillight fail, but again other than the coolant leak the car has been great.

So until recently I have had great luck with my TDI. Just did routine maintenance like tires, brakes, fluids filters, did a battery a couple of years ago preemptively as it was almost 8 years old and sounded like it was cranking slower. With my commute I didn’t want to risk it and figured.

So I guess all of this is a long winded way of saying to find a mechanic you trust, and is capable of working on one of these.
I have had a place tell me well if its leaking and you can’t see it it must be a head gasket… without any other diagnosis.

[JimmyM531]

Hopefully you have had the transmission fluid and filter changed. I just did mine over the weekend at 90K (just got the car). The manufacture of the transmissions give it a 50K service for fluid and filter.

I have not touched the transmission. Maybe I should be considering a fluid change.

Thanks,

[JimmyM531]

As set forth in my signature, I have taken two A6s from new to over 140k miles. Both became rather costly to maintain after they passed the 125k mile mark. In fact, my 2015 A6 TDI became so costly to maintain at the 125k mile mark that Audi decided to buy it back for $76,098.73 under the extended EPA Emissions Warranty (yes they paid me more for an 8 year old car than I paid for it when I bought it new). By the way, the car was dealer maintained from new, with additional oil changes every 5k miles and tranny/differential fluid every 50k miles. I wish I had better news for you.

What issues were you having with your a6 tdi at the 125k mark? Just curious as to what was becoming so costly.

[JimmyM531]

I have a 2014 A6 TDI Prestige. I have owned it since new. I have 248K miles on it now.
I have had the diesel gate scandal updates applied.

I still love driving the car its a comfortable, smooth, highway cruiser.

No performance mods, just some of the basic VAGCOM stuff like windows down with the remote and 1 or 2 others. I did add small the trunk mount spoiler.

The Good:
No major issues to speak of until recently.

I did a front wheel bearing around 145K.
Otherwise just routine service, fuel filters, brakes and tires. I had been religiously sticking to the Audi factory recommended services for oil changes and fuel filters...during the pandemic I started doing my own oil changes at 5K, and fuel filter at 10K.

I have never done glow plugs or injectors.

Embarrassed to say I haven’t done the transmission service others mentioned. I don’t have any excuses. I was using the dealer for all scheduled maintenance and they never mentioned it. Shame on me for not thinking of asking. But at this point I am not going to touch the transmission. It shifts smooth as the day I bought it.

The Bad:
I have a pretty significant coolant leak. 2 local independent service shops couldn’t diagnose, and 2 more wouldn’t even try to work on the car.

I am currently waiting on the dealer to get me in. I had an appointment for tomorrow (23 October) that I had made about 7 weeks ago… they called me Friday and canceled. Pushing me off to 24 November.
The car still runs great, tons of power, great MPG (Got 34.56 MPG at the pump today)

Searching different forums tells me it’s oil to water cooler buried deep under the intake manifold in the V of the engine… This is above my skill level. One Youtube video said it was a 12-15 hour job! That will suck at the dealer rate! But again I know my limitations on this car.

I also have a small oil leak. The car is not really using much oil between changes. Less then ½ a quart, probably closer to a ¼ of a quart.

After driving for a while and stopping at a light, or my destination I smell oil in the cabin. I do not smell it when the car is moving.
When I open the hood I can smell oil, but no visible smoke, and no tell tale signs of leaking that I can see from above using a flashlight, mirror and close eye.

I have replaced a window switch, and had a taillight fail, but again other than the coolant leak the car has been great.

So until recently I have had great luck with my TDI. Just did routine maintenance like tires, brakes, fluids filters, did a battery a couple of years ago preemptively as it was almost 8 years old and sounded like it was cranking slower. With my commute I didn’t want to risk it and figured.

So I guess all of this is a long winded way of saying to find a mechanic you trust, and is capable of working on one of these.
I have had a place tell me well if its leaking and you can’t see it it must be a head gasket… without any other diagnosis.

Thanks for the info. I too think I might have that coolant leak issue. About the 119k mark I had a low coolant light come on. I checked the overflow tank and had to add close to a quart to get it about max cold level. I have since driven it about 5k miles and the coolant is back down near the minimum cold mark, so it must be going somewhere, rather slow though. I’ve read some other forums where this seems to be an issue with this design. Gasket only stays good for so long I think. So far I’m just monitoring the coolant level before I dive in and start replacing parts.

I change the engine oil and filter every 10k. I fill it to where the computer is about max level, then once I’m due for another oil change in 10k miles, it’s down near the minimum level on the computer. Seems to use a pint or so in 10k miles, seems to be consistent since the day I got it. I’ll take that and keep going.

Still on original battery.

[Kevin1]

What issues were you having with your a6 tdi at the 125k mark? Just curious as to what was becoming so costly.

Here are the service records for my old 2015 TDI.

135,845 – 12/2/21 – Replace Oil Cooler

125,999 – 6/4/21 – Replace G784 Particulate Sensor

123,596 – 4/8/21- Ad Blue Pump, Differential Pressure Sensor, Reductive Agent Injector, Reductive Agent Tank

123,596 – 4/8/21 - Replace Rear Right Light Assembly

119,682 - 12/11/20 - MMI Screen Monitor

118,423 - 11/11/20 - NOX Sensor

110,976 - 5/22/20 - Glow Plug

108,592 - 4/7/20 - TDI FIX

104,376 - 1/10/20 - Front Brakes (39,000) Rear Brakes (31,000)

99,810 - 10/14/19 - Exhaust Clamp

94,812. - 7/22/19 - Motor Mounts (replaced differential and transfer case fluids - not part of price)

93,405. - 6/19/19 - Driver’s Front Seat Cover

73,486 - 4/20/18 - Rear Brakes (35,000)

70,041 - 2/9/18 - ATF changed, Coolant Changed, All Struts changed

65,242 - 11/6/17 - Front Brakes

62,493 - 9/27/17 - Right Rear Wheel Bearing

58,911 - 8/3/17 - ACC Brake Guard Inoperable, Replaced Diver Door Lock Actuator, 4 Wheel Alignment

55,228. - 5/30/17 - Driver Side Mirror Housing

49,859. - 3/6/17 - Replaced Sunroof Shade Liner, Front Sway Bar End Links

38,470. - 8/17/16 - Rear Brakes

35,802. - 7/14/16 - Replaced Rear Sunshade

28,956 - 4/18/16 - Replaced Rear Sway Bar End Links

28,478 - 3/23/16 - Replace Rear Right Light Assembly