VW Bora Engine Light: Timing Issue Hits Performance

Having some experience with VW engines, I dealt with a very similar issue on my 2001 VW Golf with the same engine family. The symptoms you describe match exactly what I experienced, reduced power, higher fuel consumption, and the engine light warning. After multiple error code readings, it turned out the crankshaft sensor was failing intermittently. The cam sensor readings were off because the crankshaft sensor wasnt providing accurate timing data to the ECU. This caused the engine management system to run in a safe mode with reduced performance. The repair involved replacing the crankshaft position sensor and clearing the error codes. Total cost was 340€ including diagnosis, parts and labor. Since the fix, the engine has been running perfectly with normal power and fuel consumption. Before jumping to timing chain conclusions, which would be much more expensive, getting the sensors properly diagnosed is crucial. The timing chain usually makes noise if failing, while sensor issues are more about performance and engine light warnings. To provide more specific advice, could you share: Engine size (1.6, 1.8, 2.0?), Current mileage, Are you hearing any unusual sounds from the engine? Does the problem get worse when the engine is warm or cold? Have you noticed any oil consumption issues?

Thanks for the detailed response. Last service was done at 130000km, just 2000km ago. No rattling sounds from the timing chain area, but I notice the engine light flickers occasionally before staying on permanently. The crankshaft sensor theory makes sense since the symptoms started gradually. The problem seems consistent regardless of engine temperature. The timing belt was replaced at 90000km, so I was hoping to avoid another major repair. Will get the crank sensor checked first since its a more manageable repair cost at 340€. Its good to know the camshaft sync issues could be sensor-related rather than mechanical.

Glad I could help with the initial diagnosis. Just wanted to follow up since my Golf had an almost identical progression of symptoms. That flickering check engine light before becoming permanent is exactly what happened in my case, its a classic sign of an intermittent crank sensor signal. The timing belt service history youve mentioned puts my mind at ease about potential mechanical timing issues. When our crank sensor started failing, it would sometimes send incorrect reference values to the ECU, causing the engine synchronization to seem off even though the mechanical timing was perfect. After replacing the sensor, I noticed an immediate improvement in: Engine response, Fuel economy returned to normal, No more check engine light, Proper acceleration without hesitation The relatively low cost of testing the crank sensor first (340€ in my case) makes it a logical starting point before investigating more complex timing issues. Since youre only 2000km past your last service, its unlikely to be a major mechanical problem if no unusual sounds are present. Just monitor the oil level weekly until you get it fixed, as the engine might run slightly rich when the timing signals are off, which can affect oil condition.

Thanks for the input. After reading through the responses, I feel more confident about the diagnosis path. The flickering engine light matches what others experienced with sensor issues, and Im relieved it might not be a timing chain problem. Will book an appointment to have the crankshaft sensor tested first, since 340€ is much better than a major timing repair. The engine synchronization issues and reference value errors from my scan make more sense now, knowing they can be triggered by a failing sensor rather than mechanical problems. Great point about the oil monitoring, will keep an eye on levels until the repair is done. Really helpful to hear from someone who dealt with the same symptoms and got it resolved without major mechanical work. Will update once I get the sensor checked and hopefully fixed.