moehler

I recently purchased a 2012 S63. It makes a fairly loud ticking noise at idle. You can't hear it in the car, but with the hood open, it's very loud. Hood closed, it's still pretty loud outside the car. Coming from the back of the engine, the firewall side.

I was worried it was the valves or rockers, but the Mercedes dealer said that it was the mechanical fuel pumps, and that they can get noisy. Also said it was a lot of money to replace. My recently sold 2014 CLS63 had the same engine and didn't tick like this. Maybe the pumps are different?

​​​​Does anyone else have this noise from the fuel pumps? Is the dealer correct? Just wondering how normal this is, and if anyone has done anything to address it.

billapex

My 2012 S63 (67k miles) makes a slight ticking sound from the engine as well. I can somewhat hear it when outside the car with the hood closed, but I didn't think it was anything to worry about, and my car was recently in for service at my indy shop, and he didn't say anything.

Bill

Xguy

Off the subject I noticed in your sig that you have the P30 package (increased HP if I'm not mistaken) how is your fuel economy in this? I'm getting horrible mileage in the city around 10-12 MPG (according to the computer) , and my driving is fairly easy on the car, occasionally I kick it a little, that sound just gets you going and you can't help it sometimes , mind you they're all short trips 5-10 miles and I do warm it up for a while , you know that tranny will not work properly unless I do,just wondering if this is the norm for the beast.