bum944

I once owned a brand new '95 E320. From the first day, whenever I started the car, there was a rather loud sound from the engine that went away after about 6~8 secs. It was especailly noisy in the garage since it was a enclosed space.

The dealer said that it was normal and it never became worse after 3 years, it was just a characteristic that I learned to live with it although it was not very comforting in such an expensive car. I don't recall what the source was, but think it was some kind of pump, maybe smog, steering, fuel, not sure.

Anyway, I am now looking for a W124 and recently drove one that had a very similar sound, except it never went away. It's hard to describe any sound in words, but it kind of sounds like a bad bearing, high-pitch whirring noise.

Any clues?

ZorroAMG

open the hood and listen from where it comes from..it should be at the front near the fan....silver pump...it is the smog pump

Joaquin

Some tappet noise should be expected with solid lifters at first cold start, although make sure you are running with clean oil of a low viscosity. Someone with more experience may challange this, but I can state with certainty that my 3 litre, single cam, CE has made similiar noises at startup for many years with no ill effects. At 100+ miles, we may need new valve seals. Advice: Do not add additives that will thicken your oil, this will exacerbate the clatter.