I recently bought an 04 Discovery 2, 4.6 V8, it has 122,000 miles on it, and it does Not overheat...but it ticks, of course. I've been working on cars and bikes for many years, but never a Land Rover, so I'm trying to figure this out.
The "tick" seems common the more I read.
This has a new waterpump and thermostat.
From a cold start there is no engine noise.
Once the temperature needle gets to almost half way(I assume once the thermostat opens), the ticking starts.
Previous owner told me he used 20w50 oil in it, and it has a 180 degree thermostat (can see clearly waterpump is new).
If lifter(s) were the problem, I would think they would tick immediately on cold start up, but they do not. I would think a crank or rod bearing would also make noise immediately, but the sound is definately not a knock.
Next, possibly a slipped cylinder sleeve. That fits the noise symptoms, except that the engine does not heat or overheat. I drove it a couple hundred miles on the interstate at 75-80mph with the ac on, and it ran great, and still does. No smell of anti-freeze, milky oil, or steam from exhaust.
I *assume* that a sleeve cannot slip without blowing a head gasket??
I am thinking possibly the rocker shafts are making noise.
I know that I have to disassemble the engine to find out. My Ford truck died last week, so it has left the Land Rover as my daily driver. Which screwed up my plans to tear the LR engine down. Now I need to fix it over a weekend.
The valve covers are also leaking badly. I have them and an upper intake gasket, just haven't gotten to them yet. Debating on buying a set of lifters and lower intake gasket and doing it all at once (need a power steering pump too, so all together is easier).
My questions are basically asking for any advice.
The last thing I want to do is pull the heads off and find a slipped sleeve, but if it is, it is. The symptoms just seem weird to me, as they almost contradict themselves, so if anyone could provide some insight, it would be greatly appreciated.
Thanks.

 

I had the tick for 3 years until I did my head gasket and now its completely gone. No messing up with oil or additives. I was told it was due of a ticky lifter. Just hoping that yours is same. Mine never overheated or those things you mentioned. Good luck

 

Did yours tick on cold start up?
Or, did it not tick until it warmed up?

 

Only when its warmed up. Annoying when you go to drive through fast food windows in line. Sounded like hammer tapping noise.

 

Ha! yeah it is!
Well that is good to know that LR lifters can be quiet cold, and noisey when warm.
Gives me hope that this might, just might, be a cheap fix.
I'm curoius if anyone has repaired/replaced rocker shafts and fixed the noise.
I'll find out when I open it up, I hope.
Thank you again for the info. Lifters may or may not be my problem, but it's nice to know they could be.
The whole quiet til warm up was causing me to lean away from them being the culprit. But, as said, I don't know Land Rovers.
This is a great forum!

 

Not to open any cans of worms, but just curious, what oil are you using in it now?

There are cases of sludge filled engines ticking and then when cleaned getting better.

 

Previous owner said he'd been using 20w50.
I drained about a quart out, and added a quart of Marvel Mystery oil, just to see if it would help pump up a noisey lifter. Suprisingly, it seemed to help for about 2 days. The tick wasn't as loud, and even stopped a couple times. Which also has me hoping it's a lifter(s).
My plan is now to do an engine flush, valve cover gaskets, and oil change with Rotella 15w40.
I likely will change lifters at the same time, and try Risolene addative.
I'm not one for trying bandaids, but the idea of spending money to rebuild the top end, and new bearings in bottom, only to have a sleeve slip later is kind of sickening.
I knew parts were expensive for these things...but $7200- core for a long block with top hat sleeves, wow.

 

Not even an oil change yet? May be getting a little ahead of yourself and creating work it sounds.

The MMO may help clean but will dilute the oil at the same time. Why not just do a Seafoam oil treatment for the recommended miles for flushing action. Change oil/filter and give it some time.

My D2 starting ticking shortly after purchase when warm as yours. It was a bit low on oil, topped off with some 20W50 syn, ran at 60 mph for an hour, tick went away and hasn't returned.
......

 

The oil is clean, like it was just changed recently, as previous owner said.
Valve covers leak bad, and I've been topping it off with 20w50.
I'de hate to do the valve covers and not lifters too, since it's just the lower intake and there they are.

Is there a specific amount or process for Seafoam in the oil on a Land Rover? Please forgive my ignorance, but I've only ever worked on U.S and Japanese vehicles.
It seems everything LandRover is unique unto itself...I already switched back to Disco 1 wiper arms, WTH!

 

You could have sludge and or particulate matter clogging your oil pickup. When crap builds up over time and then you add a strong detergent all the stuff that comes loose has to go somewhere.

In that case, you might get lucky and a lot of it will come out during an oil change... or its all in the pickup and you need to pull the pan and clean it out.

Just one of many scenarios I'm afraid. Could be cam bearings, piston slap, rocker arms, sticky lifter, liner movement, etc. Etc. Unfortunately several of these sound very similar to each other.