I have a 2005 XF NA Coupe with 77,000 miles, and auto trans. After driving yesterday, about 50 miles, at speeds in the 55 to 65 range, when arriving home I was hearing a ticking noise at low speeds. At about 10 to 20 MPH the noise sounded like someone driving a nail with a hammer. Could only hear this with the windows down. Windows up, it could not be heard. As the speed varied so did the ticking either slowed or increased with the speed. Coincidently, I had the "check engine" light on. It's been on for a few weeks. My code reader gave me the code P 0410, secondary air injection. Maybe the two are related, and maybe not.

In checking this site it seems that the code is because of a faulty relay in the RCM and it is not a problem to drive with it that way. One quote said the faulty relay is the fault 99% of the time.

As for the ticking noise, does anyone have any suggestions? It does not make the noise when cold or just starting out on a cruise. Could it possibly be the two piece driveshaft, bad U-joints, transmission, or rear end? Again, it only makes the noise after driving about an hour and only at low speed.

If anyone has any idea's or suggestions, I would like to hear them.

Thanks,

Jim