Date registered: Sep 2004
Vehicle: 2000 E320 aka Reichrocket
Mentioned: 0 Post(s)
Quoted: 4 Post(s)
Very loud knocking sound from engine at start-up.
MY 2000 E320 60K miles. We travelled to Europe for a week and left the car at an airport parking where they move cars around.
Came back this morning (7 days later), started the car up and a very scary, loud knocking sound came from the engine. I shut it off immediately and asked the attendant what the h*ll happened to my car. He said they parked the car there last night and there was nothing wrong with it. I started her up again, same noise. It came from the head, towards the back of the engine. I shut her off again, checked the oil, no leakage, normal level. I started again, the noise somewhat subsided and slowly disappeared in less than a minute. They said they didn't touch the engine, they just parked the car there. I drove home (about 100 miles) and everything is fine, so far. I will not drive it over the weekend, the next time I will start it up will be on Monday.
It sounded like an engine running without any oil in it, or having a bearing problem. I checked the oil level, it is down just a bit, maybe 1/4 quart/liter. I thought maybe the valve in the oil filter housing is defective and all the oil from the head leaked back to the engine hence the dry running on start-up. I had parked the car for 3 - 4 days before and have never experienced this problem.
I had owned a couple of Benzes and parked them for 2 weeks at a time and never a problem when starting up. Any idea as to what caused the sudden dry running? If indeed that is what it was, but the fact that the sound disappeared soon after starting her the third time makes me believe that it was a lubrication problem.
Out side temperature is above freezing, according to the mileage they didn't drive the anywhere except shuttling between their parking lots.
I got home around 3pm and parked the car. Just went down to start her, it is 10:30pm now, and it runs just fine.
Any ideas would be appreciated.