Although the dust has settled on the VW Dieselgate scandal, the story is still not over for diesel cars that were bought back by VW. You may have noticed that there are a lot of 2009-2015 diesel Jettas, Bugs and Golfs hitting used car lots.
If you look at the title history of these vehicles, you may see an interesting two-year gap where they only racked up 15 to 20 miles. These 2.0L TDI VWs were purchased from customers in 2016 and 2017. Then, some 300,000 of them were stored in places like the Pontiac Silverdome, Gary, Indiana’s Airport and 35 other locations around the country. Instead of scrapping the cars, VW fixed the emissions problems by reflashing the ECM and installing a larger catalytic converter and diesel particulate filter (DPF). In late 2019, they start selling the fixed cars at auction to dealers.
These vehicles meet the emission standards, and the cheat code for emissions was deleted. The only side effect is a small loss in power and a greater thirst for diesel exhaust fluid (DEF). The 2009-2014 cars now have a four year/48,000 mile emissions warranty from the date of modification. 2015 cars have a five year/60,000 emissions warranty. This emissions warranty covers a lot of parts, so check the warranty if the car was purchased recently.
The official designation of the 2.0L TDI engine is the EA189, CBEA or CJAA, a 16-valve engine with a cast-iron block and aluminum cylinder head. The engine is always turbocharged with direct injection.
VW recommends changing the oil every 10,000 miles and specifies that the 5W-30 oil must meet the VW 507 00 standard. This specification has reduced levels of certain additives that can damage the DPF. Also, using a high-quality oil will prevent carbon build-up problems that can clog the EGR valve, filter and cooler.
Fluids and Filters
Keeping a diesel running for a long time requires regular maintenance. The cabin air and fuel filters need to be replaced every 20,000 miles. The air filter is listed as a 60,000-mile item in the factory schedule, but it should be inspected regularly.
VW specifies in the service schedule that the transmission fluid and filter need to be serviced every 40,000 miles.
Diesel Particulate Filter
The 2.0L TDI engine’s DPF is a replacement item that should be inspected at 120,000 and checked every 20,000 miles thereafter, according to VW. The system performs a periodic regeneration mode and a passive regeneration when the conditions are optimal, like cruising on the freeway. The condition of the DPF is checked with pressure sensors before and after the unit. If too much of a pressure differential is detected, a regeneration cycle is started. If the customer drives short distances, the regeneration cycle could be interrupted and never completed. Some scan tools can force a regeneration cycle.
EGR Valve and Cooler
The water-cooled EGR system can be prone to internal carbon build-up and the valve can be obstructed with carbon. When this occurs, it will trigger code P0401 for insufficient flow. The carbon can be removed, but the cooler may require replacement if the build-up is too great. The EGR system has a filter after the DPF and before the EGR cooler. The pressure sensor for the DPF also acts as a method to measure exhaust gas flow through the EGR system. If the filter is clogged and causing codes, the issue might be upstream or possibly with the injectors.
Exhaust Pressure Valve
Another valve that can cause problems is the exhaust pressure control valve. This valve is located under the car after the particulate filter and increases back pressure to improve performance and emissions. Its location means it is subjected to salt spray from the front wheels. The shaft for the flap seizes due to corrosion and causes codes:
P047F: Exhaust Pressure Control Valve Stuck Open
P0477: Exhaust Pressure Control Valve Low
P048A: Exhaust Pressure Control Valve Stuck Closed
In some cases, the exhaust flow can affect EGR performance and cause code P0411. If you have the correct scan tool software, you can actuate the valve to test operation. If the exhaust pressure valve is seized, VW has introduced an improved valve.
The 2.0L TDI engine uses a timing belt that should be replaced every 130,000 miles. The belt drives the high-pressure fuel pump and water pump. Since the interval is 130,000 miles, it is key to use a timing belt kit that replaces the water pump, tensioner and idler pulleys.
VW is no longer selling diesel cars or SUVs in the US. Even before Dieselgate, they made the switch to small-displacement direct-injected and turbocharged engines. But, VW still has a loyal and growing following for the diesel power.