This weekend we had 3 days off of school and when i went to start the car it made a slapping noise. I don't know if it had to do with the weather which got down to 8 degreesF several of the nights. Also when i turn it on the economy gage went down to the middle. It was working fine before the break.
I started my car after a long weekend and now it is making a slapping noise. on 1990 Mercedes-Benz 300SE
It could be many things, unfortunately and without hearing the noise first hand or being able to do some basic diagnostic tests or be able to drive the car, its hard to say what the source of the noise may be. Check the fluid level, visually inspect the fan belts maybe one has frayed and is causing the sound. Listen and look at the engine compartment with the engine running to see if anything is obviously wrong.