Parts for your 2019 Audi Q5-Thermostat

2019 Audi Q5 Thermostat — purpose and servicing advice

Yes, the 2019 Audi Q5 is fitted with a thermostat. Audi’s workshop literature for the FY (B9) Q5 cooling system and the Audi Self‑Study Programmes covering the EA888 Gen.3/3B 2.0 TFSI and the V6 TDI families describe a map‑controlled thermostat integrated into the coolant module. These sources outline how the engine control unit actively manages coolant flow and target temperatures via the thermostat to balance emissions, performance and reliability.

On the 2019 Q5, the thermostat’s job is to bring the engine up to temperature quickly, then hold it in the sweet spot under different loads and ambient conditions. It regulates coolant flow to the radiator and, being electronically managed, can raise or lower the operating window for better efficiency on the motorway or extra cooling when towing up a hill on a 35 °C summer’s day. Faster warm‑up means lower fuel use and reduced wear, stable running temperature means consistent power and cabin heat.

While the thermostat isn’t a routine replacement item, it lives in a busy part of the engine bay and can wear over time. Owners may notice slow warm‑up, a heater that never gets toasty, or the opposite—temperature spikes and warning lights—if it sticks. Modern faults can also be electrical: a stored DTC (like a P0128), fans running harder than usual, or poor economy. Coolant residue around the housing or under‑tray is another giveaway.

• Service tips: inspect the coolant module and hose junctions for pink/white crusting, check warm‑up time on a cold start, and scan for cooling‑system DTCs.
• Replacement advice: use an OE‑quality thermostat/housing assembly with new seals and fasteners, refresh coolant meeting the correct VW/Audi spec, and bleed the system properly (a vacuum fill or factory bleed procedure helps avoid air pockets).
• Intervals: follow the Audi service schedule, many workshops will test coolant condition at each service and replace coolant at set time/kilometre milestones or whenever the thermostat or water pump is replaced.

A well‑behaved thermostat helps the Q5 feel smooth, economical and ready for long Kiwi and Aussie road trips. If there’s any doubt, a quick pressure test and scan can save a headache later.

FAQ

Where is the thermostat on a 2019 Audi Q5?
It’s part of the coolant module/thermostat housing mounted on the front side of the engine (transverse 2.0 TFSI) with several hose connections and an electrical plug. Access typically requires removal of covers and intake ducting.

What are common symptoms of a faulty thermostat on this model?
Slow warm‑up, fluctuating temperature, poor cabin heat, overheating under load, the radiator fan running more than usual, and fault codes such as P0128. Coolant seepage around the housing is also common as the assembly ages.

Does the thermostat need periodic replacement, and what does it cost?
It isn’t a scheduled replacement item, but many are replaced during the vehicle’s life due to wear or leaks. Costs in Australia and New Zealand vary with parts brand and labour time, budgeting for several hundred dollars fitted is typical, more if combined with a water pump or hose set.