A load test of the battery is in order. Most parts stores will do this for free.

Speaking of starters, I went through two Bosch remans in my 240D in less than four years. I grabbed a cheapie from Autozoo and I noticed the cranking speed is faster than the Bosch ones ever were.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.