VW Sharan Diesel Running Rich, Injector Issues Alert

Had nearly identical symptoms on my 2019 VW Tiguan TDI. The poor fuel economy and rough running were classic signs of faulty fuel injectors. The engine management detected incorrect air-fuel ratio and triggered the check engine light. After diagnosis, two fuel injectors needed replacement due to carbon buildup affecting spray pattern. The rough cold running was happening because the injectors could not properly atomize the fuel. This created uneven combustion and the jerky acceleration you described. This is a serious issue that requires prompt attention since bad injectors can: Cause internal engine damage if left untreated, Lead to increased emissions, Create starting problems, Further decrease fuel economy The repair involved: Testing fuel injector spray patterns, Removing intake manifold, Replacing defective injectors, Cleaning remaining injectors, Computer reset and calibration, Test drive to verify proper operation The symptoms disappeared completely after repair. Would recommend having it checked soon, as continuing to drive with faulty injectors risks more extensive engine damage.

Thanks for sharing your experience with the injector issue. Faced something very similar last month with my Sharan, rough idle, poor performance and all those fuel economy problems. The repair shop found the oxygen sensor was also damaged, likely from the rich mixture running too long. They had to replace that along with cleaning the intake manifold and air filter. Just wondering how the repair has held up for you? And if you remember the total cost? Want to compare what I paid to make sure the price was fair. Have you noticed any other issues pop up since getting it fixed?

The repair has held up perfectly since having the faulty fuel injectors replaced. The engine runs spot-on now, no more rich fuel mixture issues. The repair shop found one bad injector that was causing the system to dump excess fuel. After installing a new fuel injector and cleaning the intake manifold, all symptoms cleared up. Total cost came to 515€ which included: New injector, Labor for removal/installation, System diagnosis, Computer reset, Test drive verification The check engine light has stayed off and fuel economy returned to normal. The rough running and sluggish acceleration completely disappeared. Have put about 15,000 km on it since the repair with zero fuel system related problems. Important to catch these issues early, running too rich can damage the oxygen sensor and catalytic converter over time. Regular maintenance and prompt attention to check engine warnings helps prevent cascading problems.

Thanks for the information. I finally took my Sharan to a trusted mechanic last week. The diagnostic scan revealed bad fuel injectors along with a failing oxygen sensor. Makes sense since I had been driving with the check engine light on for a while. The total repair came to 890€ including: 2 new fuel injectors, New oxygen sensor, Full system cleaning, Computer reset The mechanic showed me how carbon deposits had clogged the old injectors, causing the poor air-fuel ratio and performance issues. The sluggish acceleration and rough running are completely gone now. Fuel economy is back to normal too. Really glad I got it fixed before more damage occurred. The car runs like new again, smooth idle, strong power delivery, and no warning lights. Learned my lesson about not ignoring check engine warnings and getting issues checked promptly. Will definitely keep up with maintenance to prevent similar problems in the future.