280E whistle/whirring noise when cold

Hi, after reading heaps here for the last few months, finally got the courage to post.

My 1981 280E (253,000 km) is immaculate - recently had valves shimmed, uses no oil to speak of - uses about 500ml of water every 500km.

The problem I have (or is it not a problem) is that when cold to 70 degrees Celcius there is a whistling whurring noise from the front of the motor.

Everything else with the vehicle is fine - is it a slipping belt? head gasket on the way? vaccuum problem?
I dont know! Hopefully someone can help!

regards,

Zappa

[mendez300SD]

hello! you can use a hose (long hose abaout 1/2" diameter )as a
stetoscop. putting one side on your hear and sccaning noise at the other extreme. good luck
sorry grammatics.
Alberto.

[JDUB]

If you can turn the alternator pulley by hand and it slips on the pully the belt is probably loose. If you are losing coolant the water pump may be depositing the coolant on the belt causing a squeal until it warms up a bit. I'mnot familiar with your model and don't know if you have a belt tensioner that may be worn. It sound like a loose belt to me. If it is a V- belt they get glazed after years of use and harden a bit, and squeal.

[Hocky]

The belt will usually squeal loudly if its loose or has fluid on it making it slip or is worn out and this is most evident when it is cold started. Happens very commonly around the neighbourhood especially in the mornings when cars are going out to work or school duties. I find this in W124s mainly, maybe they are the most popular in my neighbourhood. Loose belt, tensioner problems, worn out belt , whatever, get it checked by your trusted techie or you will be in for a lot more trouble as they will find "invisible and hocus pocus" breakdowns in the rest of the car which may really empty your pockets overnight!