Question 1

Haldex four-wheel-drive coupling failure (Tiguan AD1)

Accepted Answer

The Haldex coupling that sends power to the rear wheels relies on a small electric pump and clean fluid. When the pump fails or the filter clogs, the car becomes front-wheel drive only, with a 4x4 warning or no warning at all. Regular fluid changes are often skipped.

Question 2

EGR cooler coolant leak (2.0 TDI)

Accepted Answer

The EGR cooler on the 2.0 TDI can crack internally, so coolant is lost with no visible external leak. Symptoms include a slowly dropping coolant level, white smoke or a sweet smell from the exhaust and, in advanced cases, overheating. Some cars were covered by a manufacturer recall or extended warranty.

Question 3

AdBlue (SCR) system faults (2.0 TDI)

Accepted Answer

The SCR emissions system on the 2.0 TDI can develop faults in the AdBlue pump, tank heater, NOx sensors or dosing injector, often caused by crystallised fluid. The dashboard shows an emissions warning and a countdown in miles after which the engine will not restart.

Volkswagen TiguanTiguan AD1

Known issues and common problems

Volkswagen TiguanTiguan AD1

Known issues and common problems

Haldex four-wheel-drive coupling failure (Tiguan AD1)at 120000 km · 1 solutionsMedium

EGR cooler coolant leak (2.0 TDI)at 140000 km · 1 solutionsHigh

AdBlue (SCR) system faults (2.0 TDI)1 solutionsHigh