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strange mechanical engine noise

09-18-2014, 12:37 PM
I have a problem with a 2007 Mercury Montego which is hard to diagnose because it is not always present. I have a strange noise upon start up that sounds destructive but so far has not caused any damage that I am aware of.
It happens more commonly after the car sits overnight or after it hasn't been started for a day or more.
I have had several mechanics check it out but were unable to find anything.
I was told that it probably is a "dry start-up" caused by the oil filter allowing the oil to drain from the top side of the engine. I'm not buying that because I've owned at least 50 cars during my life and never had any of them do this.

I thought maybe something like an alternator or A/C bracket had not been tightened properly and causing the clunking noise. But after inspection nothing found. So I'm looking for someone who might have an answer to my problem.

09-18-2014, 08:38 PM
Worn out Harmonic balancers with thud or knock on start up or shut down- seen it several times..

09-18-2014, 10:20 PM
Thanks for your input. I will definitely look in to that, however the car only has 34,000
miles, but I suppose it could be defective. I bought it with 29,000 so I don't know what was done to it before I bought it. Thanks again

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