MajorCommonCooling

Audi A7: 3.0 TFSI supercharged water pump and thermostat housing coolant leaks

3.0 TFSI supercharged water pump and thermostat housing coolant leaks is a common cooling fault on the Audi A7 on the 2011–2018 cars, and we rate it major. Putting it right costs $1,200 to $2,800 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 6 documented faults on the Audi A7.

Vehicle: Audi A7
Engine: 3.0L
Years: 2011–2018
Fuel: petrol
System: Cooling

This page covers the Audi A7 as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Audi A7 faults6 documented faults on this model

What you are looking at

An annotated photograph of an automotive engine thermostat identifying the wax capsule and both disc valves. — A double-valve engine thermostat, labelled: the wax capsule is what sticks.
Dougsim · CC BY-SA 3.0 · Wikimedia Commons

What goes wrong

The supercharged 3.0 TFSI V6 uses plastic water pump and thermostat housings that commonly crack or weep from around 100,000 to 145,000 km, with early (2011-2012) engines worst. The thermostat sits under the supercharger, so the job means removing the blower, which is why it costs more than the parts suggest. Left alone, a slow leak becomes overheating, and running a hot aluminium V6 low on coolant risks head gasket and cylinder head damage. There is no recall or extended warranty for this; it is a normal wear repair on this engine.

What you would notice

Coolant level dropping between services
Sweet coolant smell from the engine bay or vents after a drive
Pink or purple crusty residue around the front of the engine or under the car
Temperature gauge climbing or slow to warm up
Radiator fans running hard after switch-off
Coolant level warning on the dash

How to check it

Where to look. Front and top of the V6 engine; the thermostat housing sits under the supercharger in the engine valley, the water pump at the front of the block

With the engine cold, open the bonnet and check the coolant expansion tank is at the MAX line and the coolant is clean pink/purple, not brown. Use a phone torch to look down the front of the engine and at the ground under the front of the car for pink crusty residue or drips. On the test drive, watch that the temperature needle settles in the middle within 10 minutes and stays there in traffic. After the drive, sniff around the grille and bonnet edges for a sweet coolant smell. Ask whether the water pump and thermostat have been replaced and when; a receipt for both is a big plus on a car over 100,000 km. If a workshop inspection is possible: have the cooling system pressure tested and the underside checked on a hoist for weeping at the pump and thermostat housing, and scan for thermostat and coolant temperature fault codes.

Parts involved: Thermostat, Water pump.

What it costs to put right

$1,200 to $2,800 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Has the water pump or thermostat been replaced, and do you have the invoice?”
“Do you ever have to top up the coolant?”
“Has the car ever overheated or shown a coolant warning?”

Now check the Audi A7 you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

Euro Premium Parts: Used Audi A7/S7 C7 Buying Guide (3.0 TFSI thermostat and water pump failures)
CanAuto Performance: Audi 3.0T Reliability Guide, water pump and thermostat (A6/A7 listed)
Euro Auto Pro (AU): Common Problems of Audi A7 4G 3.0 TFSI, cooling system problems

Audi A7 buyer questions

Is 3.0 tfsi supercharged water pump and thermostat housing coolant leaks serious on a Audi A7?

We rate it major and common on the Audi A7. The supercharged 3.0 TFSI V6 uses plastic water pump and thermostat housings that commonly crack or weep from around 100,000 to 145,000 km, with early (2011-2012) engines worst. The thermostat sits under the supercharger, so the job means removing the blower, which is why it costs more than the parts suggest. Left alone, a slow leak becomes overheating, and running a hot aluminium V6 low on coolant risks head gasket and cylinder head damage. There is no recall or extended warranty for this; it is a normal wear repair on this engine.

How much does it cost to fix on a Audi A7?

$1,200 to $2,800 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Audi A7 years are affected?

Our research records this fault on the 2011–2018 Audi A7. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.