Reach you hand back behind the upper manifold and see if a spark plug wire is loose on the coil pack (arcing against something). You might have to lay on the engine (with a blanket) to get your arm/hand back there to check all the wires, it's a science, you will not be able to see anything, just feel and touch, hehe.

Sounds crazy, but this exact same thing happened to me and that is what it was. Happened exactly like what you are describing (overnight), especially with the faster "clicking" noise on increased RPMs. If you can notice it from the inside with the windows rolled up, like it's ticking against the firewall in the middle, then that's what it is I bet.

The wire can come lose, barely clinging on, so it will still provide enough spark to fire the cylinder (you will not notice any engine performance degrades), but will throw a heck of a clicking noise, sounding like heavy valve/lifter noise at idle. The give away though is the fast clicking (almost electrical) sound on acceleration. Because of where these idiots mounted the coil back, the sound echos all over the place.....

 

So back to your question, if your engine is now making a noise I would suggest you have a mechanic find out why before you do some damage.

 

Mine started tapping at idle after I changed my oil the first time. I also did not know what type of oil was already in it, just know it makes noise now. I have tried all different weights of oil but nothing has made a difference. The noise is probably the sleeves ticking up and down 1/16 of an inch.

 

Ok I understand now. I have to drive a couple of miles this morning and I'll see if it's still doing it. It may have been me just being paranoid.

 

can you id where the noise is comming from? is it louder above, under, to one side/ front/rear? does it change with engine rpm in sync or is it erratic? does it do it under load, or does the sound change revving sitting still, under light and hard acceleration? etc.etc

 

Thanks sloan74 I'll check that tomorrow. Also, thanks Discomike: I went back by a friend's garage here in town who works on American cars (No land rovers sadly) but he seemed to think that the oil is too thick for the engine and that I should drain it and put 10w-40 in it. Anyway, I recorded it doing it so you guys can actually HEAR what it's doing. YouTube - ‪DIscovery II Engine Knocking‬‏

 

You don't think 15w-40 is too thick?

 

Nope.
Alittle thing you need to know about motor oil, the bottom number is how thick the oil is when cold, the top number is how thick it is at temp.
So a 10w-40 at temp is the same thickness as a 15w-40 at temp.
The only difference between the two oils is how well they flow when cold.
Here is a oil flow chart, take a closed look at the temps at which a motor oil is good for.
The lower the top number the less heat the oil can take.
http://www.carbibles.com/images/saerates.jpg
I use 15w-40 in my truck with no problems, I like to use and also recommend using the 15w-40 because it is a heavy duty oil and it give excellent wear protection and can take tons of abuse.
Bottom line, unless you put gear lube in your engine the oil is not your problem.
Also the 15w-40 is a very high detergent oil, it not only prevents engine sludge it will also clean out engine sludge as you drive.
And just a FYI, the oil filters that the quick lubes use are of the cheapest quality, they cant make money buy using a high quality oil filter.
Think of it this way, the filter contract goes to the lowest bidder.
You can bring your own filter and have them install that for you.

 

Thank you.
Now to clarify is that for the DII? LR3? LR4?
My DI owners manual has a whole page with a oil chart stating which oil to use during which temps, everything from 5w-20 upto 20w-60, even straight 30 weight is listed.
The dealer that my truck was always serviced at before I bought it was always 10w-40.

 

This Spring I decided to quit spending the big bucks on the Mobile 1/Fram 301 combination and switched over to the 15w40 RotellaT with a Bosch filter. Since then the wife has been driving it, but today, (which was 98 degrees out) I took it on a Costco run and readily noticed how quiet the engine was turning over absent the tick it sometimes had. With 105k miles on the clock it seems to be running better than ever.