I don't know anything about 450's but check the voltage at your starter solenoid and make sure you have enough current getting to it because that's a fairly common cause of starter malfunction - not enough power to shoot the starter sprocket out to engage the ring gear.
Also, bevsure and check (I had a similiar problem and guys on this site suggested this) your ground strap and clean it and make sure you have a really good ground.
Harvey

sorry this was supposed to go with igolf's starter/ring gear problem.

Does anyone know where exactly the ground strap is on a W123 280E? And how do you clean it?

I've had intermittant hot start problems - where the starter motor is refusing to turn when the car has been driven for some time, and wonder if this might be the cause.

Thanks

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Chris Hunter

1977 W123 280E auto
Cayenne Pepper orange
289,000km and goin' strong ... touch Zebrano.

I doubt that is the cause. You will need to replace the starter in most cases to get rid of this. This is caused by the heat soak that occurrs after you turn off the engine. You should check the connection at the starter wher the trigger wire is.

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Benzmac:
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