Water Pump / Thermostat Leaks
ModerateCooling SystemLater petrol and diesel engines still suffer coolant leaks from pumps or plastic thermostat housings.
Est. Repair Cost: £350–£750
Reliability GuideCommon Problems with the
Common Problems with the
2016 Audi A4 Mk5 (B9)
The launch year brought a sharper, more efficient B9 with Virtual Cockpit and updated engines. Water pump and thermostat housing leaks are the primary concern across the range, with LED DRL failures adding to the bill.
What changed for 2016
- •Launch with 2.0 TFSI and 3.0 TDI engines
- •New MLB Evo platform
- •Virtual Cockpit and updated MMI
- •LED headlights as standard on higher trims
Common MOT watch-outs
- !Water pump and thermostat housing leaks
- !LED DRL and indicator failures in headlight units
- !NOx sensor and AdBlue faults on diesels
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Known Issues
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Serious
1
Moderate
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Minor
All Known Issues
Buying Tips for 2016 Audi A4 Mk5 (B9)
- ✓Check coolant level cold and inspect around the pump and housing
- ✓LED headlight module failures require complete unit replacement — budget £300–£800 per side
- ✓TDI buyers should verify NOx-sensor and AdBlue history