I've had my 1997 Range Rover for about a month. Has 130k miles.
It was perfect before and sounded perfect.
But the other day i changed the oil, and the next day a weird ticking started and my oil light came on. I know it has a minor oil leak but nothing insane.
I used 10w-40 high mileage oil.
Now when i first start it it sounds fine and the oil light is off, but after about 10 minutes of driving the light comes on and it begins to tick.
Anyone else have this problem? Could it just be the wrong oil?

 

you have diagnosed your own problem "I used 10-40 high mileage oil."
replace the 10 weight oil with a 15w-40 Shell Rotella (diesel) and your noise will go away.

 

The car isn't a diesel though

 

Yes, but it has characteristics that work well for these rover gas engines.

 

Alright I'll try it and keep you updated

 

Oil light comes on is very bad sign. This happens at about 7 PSI. Should be 40 - 50 PSI when running at speed. If light comes on at idle can indicate very hot and thinned out oil, or oil pan pickup is sludged up. A mechanical oil pressure test test would be a good idea. The light goes out around 8 PSI. So you don't know if you are running 12 PSI when you need to be 3 or 4 times that.

 

I still have the old oil from before I changed it and it didn't make a noise, would it be a good idea to put it back in until I can afford new oil?

 

No, the new 10W40 oil should not be causing the noise if it was good quality. The new oil may have broken loose some sludge that has blocked most of your oil pickup screen.

 

Where is the oil screen so I can check?

 

inside the oil pan