Jaguar XJ Stalling & Starting Issues, Bad Cam Sensor

Had similar symptoms on a 2006 Jaguar XK8. The check engine light came on and engine control system was showing multiple misfires. The camshaft position sensor readings were inconsistent, causing problems with ignition timing. The root cause was a defective encoder wheel on the camshafts. This is actually a more serious issue than just a faulty sensor. When the encoder wheel deteriorates, it cannot properly signal the camshaft position to the engine control unit. This causes the erratic starting and stalling issues you describe. The repair required removing the valve cover to access and replace the encoder wheel assembly. It was about a 6-hour job since several components needed to be removed for access. The camshaft sensor itself was replaced as a precautionary measure during the same repair. This is not a simple sensor swap, it requires experience with Jaguar engines and proper diagnostic equipment to verify the fix. Would recommend finding a shop that specializes in Jaguar repairs, as incorrect installation can lead to more engine problems.

Thanks for sharing your experience with the encoder wheel issue. I had my XJ fixed about 6 months ago with nearly identical symptoms, rough starts, stalling at idle, and sensor failure codes. Ended up taking it to a specialist who diagnosed both camshaft position sensor problems and a worn encoder wheel. Would you mind sharing what the total repair cost was in your case? My bill was around 850€ for parts and labor, but prices can vary quite a bit. Also curious if youve had any other engine issues pop up since getting it fixed? My car runs great now but always good to know what to watch out for.

The encoder wheel and camshaft position sensor repair on my XK8 came to 695€ total, including parts and labor. This was a bit less than your cost, but prices do fluctuate based on timing and parts availability. After fixing the defective encoder wheel and replacing the camshaft sensor, the engine has been running perfectly. No more check engine lights, stalling issues, or engine misfires. The specialist shop did a thorough job with the sensor testing and installation, which likely prevented any follow-up problems. In the 6 months since the repair, I havent experienced any related engine issues. The rough starting and erratic idle problems completely disappeared once the camshaft position components were properly replaced. Just make sure to keep up with regular maintenance and oil changes to prevent premature wear on the new parts.

I took my XJ to a specialist mechanic last week after getting all this helpful advice. Like many others mentioned, it was indeed the camshaft position sensor and encoder wheel causing the problems. The repair bill came to 780€, which seems pretty reasonable considering the work involved. The mechanic showed me the old encoder wheel, it was pretty worn down and explained why the engine control unit was getting confused. They had to remove quite a few parts to access everything, but the car runs perfectly now. No more check engine light, no stalling, and it starts right up every time. Really glad I went with a Jaguar specialist instead of my regular mechanic. They knew exactly what to look for and had the right diagnostic equipment to confirm the camshaft sensor readings. Would definitely recommend anyone with similar symptoms get it checked out by someone who knows these engines well.