Audi TT

The water pump on the CRLB is driven by the timing belt. If it fails early the belt comes under tension and snaps. Simultaneous replacement of timing belt and water pump is mandatory.

Symptoms: Coolant loss, overheating warning, squealing from the belt area, coolant below the front of the vehicle.

The EGR cooler on the EA288 is thermally stressed by hot exhaust gases and can develop leaks. Coolant enters the intake; the loss is often minor and hard to locate.

Symptoms: Gradual coolant loss without visible external leak, white smoke from exhaust, elevated pressure in cooling system.

With predominantly short-trip use the regeneration temperature is never reached. Ash and soot accumulate; above approximately 90% loading only a replacement is possible.

Symptoms: DPF warning light, power reduction, increased fuel consumption, engine in limp mode.

The variable guide vanes on the VTG turbocharger stick from soot deposits and lock in one position. Result: poor boost pressure control, power loss.

Symptoms: Whistling or hissing from the turbo area, power drop at mid-range rpm, boost pressure fault in the fault memory.

The S tronic mechatronics unit can develop faults that manifest as shift problems. Repair costs vary greatly depending on the extent of the damage.