My 08 LR3 runs and drives just fine but for a while now I have this odd "cluck-cluck" sound while driving on the highway. Always the same two repeated sounds coming from somewhere behind the front seats. The sound repeats every 15 to 20 minutes. It only happens at highway speed, never at lower speeds. At first I thought it might be something with the EPB however that works fine. Any ideas?

 

With not much to go on you might still take a look at the rear driveshaft central bearing. It is supposed to have rubber around it but once the rubber goes it’ll clunk. If you’re doing 65 mph on 101 (example) with the tarmac being absolute crap, many things will bounce around underneath.

of course you could entertain us with a sound sample 👀

 

I am pretty sure it is not the driveshaft. A worn center bearing would not make exactly the same same sound at roughly the same time intervals. It would be more random. Also, the highway here is perfectly smooth. Don't know how to delete the 20 minutes of random noises that I would probably record before mystery noise showed up. I don't think hearing the actual sound would help much. It is always the same, just 2 tones together like something switching on and off. I'm not loosing sleep over it but wonder what it could be caused by.

 

Could it be the NAV DVD drive under the driver's seat?

 

I will have a look but don't know why that would only make the sound when on the highway.