Maybe I should go back and read more thoroughly, but I don’t think anyone mentioned an exhaust leak. I’ve had several V8’s (no LR’s yet) where loose exhaust manifold to head nuts sounded very much like an engine tick.

 

@Harvlr Good suggestion but no it is lifter tick.

However further update about 80 miles after seafoam added lifter ticker greatly reduced.

 

Can you explain the Seafoam procedure in detail? I might want to copy it.

 

@Brandon318 Seafoam is easy, but you have read the directions. It is 1 oz per quart/liter of oil, (not the whole damm can) I run a big filter so I use 6.5 oz that is it. Pour it in and drive your Disco. They recommend 300 to 500 miles before an oil change, but is really mostly detergents so more mileage will not hurt anything.

The reason you use the recommended amount is it a slow gradual process, of de-varnishing and desludging. It avoids all the nasty side effects of the the harsh stuff.

I generally toss a can of liquidMoly Hydraulic valve lifter conditioner in with each oil change as well, same idea it helps keep things clean, it is cheap enough that even if it does not do much it still helps.

If nothing changes after the seafoam, you pretty much have to open her up, that is the sucky part.

 

Just an update:

1. The Disco is cursed

The tick came back after a 40 minute drive and then sitting for 6 hours, quieter than the 1st instance but still too loud, note you can only hear it windows down.
Went to the dump the next day and the tick was there, but much quieter never shut down. While idling the noise lessened, engine temp about 177. Went to the recycling area of the dump unloaded a bunch stuff engine temp 183, noise was almost completely gone in 10 minutes of idling.
The seafoam is still working I have another 150 miles to go.

My question as a random thought came up, it it possible I have a sticky rocker arm rather than a sticky lifter.

 

IMO take the valve covers off (no plenum removal) to check rockers push rods) - might be a simple fix with a rocker arm or push rod

 

An active component of Sea Foam is a solvent. The solvent is volatile (low boiling point), so mostly evaporates the first time the engine gets up to temp (so says Motor Oil Geek). B-12 Chem Tool is also a solvent. I think they describe a process of running the engine in short episodes, not allowing it to heat up to get the most active cleaning.

I had a new ticking rocker arm. Alloy type has a crimped-in bearing cup for the push rod. The crimps were not quite placed correctly, so that bearing cup could spin in the rocker arm (after 5,000 miles or so). That tiny bit of looseness was enough to generate a tick that was quite loud. Drove it for a couple years before fixing it, but probably could have kept going indefinitely.

 

@JohnZo Thanks for the feedback. Once the new floors and kitchen are in I can dedicate some time to pulling things apart. We are packed so a least I can run around and see if things are continuing to improve.