My new to me 1991 300E, makes a ratchet sound after sitting up for two days. There are three to four clicking sounds and then it’s gone. The sound is coming from the front of the engine and doesn’t occur if the car sits just over night only after sitting for the weekend.

How and what do I look for?

Thank you in advance for your help.

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1990 420SEL
1995 E320 Coupe
2000 SL500
2009 ML320