How to Winterize Audi Diesels
This bulletin applies to all 2011-2016 Audi models equipped with a diesel engine. DTC P0087 may be stored in the ECM (fuel rail/system pressure too low). Drivability concerns such as hard starting/no-start may be present. The fuel pump in the tank may make a straining noise.
Diesel fuel requires additive blending (winterization) to be useable in low temperatures. At temperatures below 20 degrees F, No. 2 diesel with insufficient winterization blending may lose its fluidity due to wax separation. This may clog the fuel filter or in-tank filter.
No. 2 diesel is blended by refineries to various levels of winterization based on month, geographical location and ambient air temperatures for a given region. Although rare, during sudden periods of extremely low temperatures, fuel stations may not be adequately prepared with No. 2 diesel fuel with sufficient winterization to resist wax formation or gelling.
If fuel gelling is suspected, allow the vehicle to warm up to shop temperature before further diagnosis. If the engine starts and operates correctly once warm, inspect the fuel level. If the fuel level is half of a tank or less, top off with local No. 2 fuel from a brand name station with high turnover.
If fuel level is greater than a half of a tank, drain the fuel tank and then fully fill with local No. 2 diesel fuel. Replace the fuel filter and drain the water separator.