T-Roc Flashing CEL Points to Costly VANOS Failure

Had similar symptoms on a 2017 VW Golf GTI. The flashing check engine light combined with high fuel consumption pointed to VANOS failure, which was causing engine misfire and low power output. The issue turned out to be a defective camshaft solenoid valve in the VANOS system. When these solenoids fail, they cant properly control valve timing, leading to rough running and poor performance. The diagnosis showed irregular timing chain tension as well. The repair involved replacing both inlet VANOS solenoids and cleaning the oil passages. This is a common failure point on these engines, especially after 100000km. The job requires removing several components to access the VANOS unit. Other potential causes for these symptoms could be: Clogged oil passages, Failed timing chain tensioner, Damaged wiring to VANOS solenoids, Low oil pressure Would recommend getting a proper diagnostic scan before proceeding. If its confirmed VANOS failure, postponing repairs typically leads to worse engine performance and potential engine damage. The quoted price aligns with typical VANOS repair costs considering parts and labor involved. This is considered a serious repair that affects engine timing and performance.

Thanks for sharing your experience. I had the exact same issue with my T-Roc last winter. The flashing CEL and fuel consumption increase matched my symptoms perfectly. Before I commit to the repair at my shop, could you share what you ended up paying for the full VANOS solenoid replacement? Also curious if youve had any related issues pop up since the repair was done? The oil sludge buildup my mechanic mentioned has me worried about potential future problems with the inlet camshaft, even after fixing the current VANOS failure.

Got the complete VANOS repair done last month and can report the issue is fully resolved. The variable timing system is working perfectly now after replacing the faulty inlet camshaft solenoid valve. Total cost came to 250€, which was much less than initially quoted since it turned out to be just one defective solenoid rather than a full VANOS unit replacement. Since the fix, fuel consumption returned to normal and the check engine light hasnt reappeared. The engine runs smooth with proper variable timing control. No related problems have emerged. Regarding oil sludge concerns, regular oil changes using the correct grade oil are crucial for preventing VANOS issues. The BMW VANOS system is sensitive to oil contamination, which can affect the inlet camshaft operation. Would strongly recommend following a strict maintenance schedule with quality oil to avoid future variable timing problems. The initial symptoms you described match classic VANOS failure indicators. Getting it fixed promptly was definitely the right call to prevent more extensive engine damage.

Thanks for all the feedback. Wanted to update on how things turned out. Finally took my T-Roc to the shop last week after the VANOS failure symptoms got worse. The flashing check engine light was really concerning me. The mechanic confirmed the variable timing system had failed. They found the inlet camshaft solenoid was completely shot, causing the engine misfire. The timing chain showed some wear too but was still okay. Total repair came to 1100€, slightly less than quoted. They replaced both VANOS solenoids and cleaned all the oil passages while they were in there. Car runs like new now, no more flashing lights or excessive fuel consumption. Really glad I got it sorted before any serious engine damage occurred. Going to stick to a strict oil change schedule from now on to prevent future VANOS issues. The shop recommended synthetic oil specifically designed for engines with variable valve timing.