03 discovery knocking/ticking

[Mama.riha.90]

So my rover has developed a knocking sound at idle, that disappears after I reach about 25 mph. I only hear it at idle or if I'm parked with it running.

It's not a consistent knock, nor is it rhythmic. It goes something like,

knock, knock,.........knock, knock, knock,........knock.........knock, knock.

It seems to not do it at start up but rather once the truck heats up.

My hubby knocked on the cats with a rubber mallet, and it seemed to go away for a bit but now it's back.

My conclusion is that it's either a rod/lifter knock, or a bad cat knock. I'm not sure the symptoms or difference of the two. I have tried Stp oil treatment thinking that if it was an engine knock it may help. But that did absolutely nothing.


Any suggestions of what it might be?

 

[joey]

Sounds more like a slipped liner... get a mechanics stethoscope and check for the sound (a long screw driver works as well).

Has it over heated?

 

[Mama.riha.90]

No over heating. Do I use the stethoscope to listen to the cat? What specifically do I listen for?

 

[joey]

Listen to just about everything and try to locate where the rattle noise is coming from if the cats you will hear it loud there and not as loud anywhere else.

 

[superrocco16v]

I have the same problem , mine is also a 2003 I refresh the long block 1/2 set of gaskets, new piston rings , resurfaced heads, mechanic checked the Crank and the rods and no sign of unusual damage then put back together and the same sound again went to LR dealership and talk to the shop head mechanic and recommended to get a dif year engine and add that They don't even know what is it


Sent from my iPhone using Tapatalk

 

[Gromeo]

Sleeves

I have been told this is due to the design of the engine.

Once heats up and at idle you can hear a slippage on a sleeve.
-Solution I was told was remove the small block and bring to machine shop to remove OEM sleeves and replace with 'top hats'.


These are machine pressed to top and when heat up do not leave any space inside the shaft. Therefor, no knocking ticking noise against sides of sleeve.