engine rattles when cold are usually caused by lack of oil circulation in engine.
this can be caused by old oil, wrong oil viscosity.or incorrect valve tappet clearences
your vehicle may just need a good old fashioned tuneup and oil change
Most likely a rattle from that area in the engine bay when cold that subsides somewhat when engine gets warm.
Often a knock when cold is caused by piston slap, which is pistons rocking in the cylinders until they expand in size when the engine warms up.
The ticking sound you are hearing from the rover when it's cold is likely due to the metal components expanding as they warm up. This expansion can cause parts to move slightly, creating the ticking noise. It is a normal phenomenon and should not cause concern as long as the sound goes away once the rover warms up.
You don't say what year or which model you have. However, the catalytic converters will rattle upon decelleration when they need replacement. A simple check is just crawl underneath and smack or shake them. If they are used up you will hear them rattle. **Do this ONLY when they are COLD!!! They get extremely hot!!!** OR take it to a muffler shop/Dealer and have them checked. They will do the same thing for alot more money :-)
Mine does
The rattle snake
the rattle pick 62
Range Rover Classic EFI will foul spark plugs if you start and stop the engine when cold. All models with 3.5, 3.9, 4.2, 4.0, 4.6 will wear out camshafts and/or blow headgaskets from 150,000km to 200,000km.
if it is more of a slapping rattle like metal to metal for every revolution of the motor check your crank pulley... my Zuk was making a similar noise... ended up being the 4 bolts holding the pulley on and sheared them right out of my crank sprocket... it sounds rediculous but trust me its worth checkin out
when you are done with it or when it stops being cold.
The rattle may be caused by either a bad bearing in one of the pump wheels, (ie water pump, power steering, etc.) or the belt tensioner has seized. My tracker's tensioner had seized up, and while it didn't rattle on acceleration or deceleration, it would rattle when the engine was started on a cold day, due to the belt being lose. It wasn't a squeal either, but it sounded like someone was shaking a pop can full of marbles. Living in northern Ontario Canada, we have some cold days, and it would rattle quite loudly. Other than that i really have no other ideas. Hope this helps! Good luck!
smelling