Hi fellow Disco owners, I haven't posted here for awhile due to a lot of work related travel.

Back in mid January when we had low morning temps in the mid 20's here in Houston, I started to notice a slight tapping sound coming from my engine after a few cold morning start-ups. It seems to be more in the lower end of the engine and I mainly here it if I stand next to the front wheel on the passenger side but I can also hear it when the windows are up and it sounds like it is just behind the passenger area firewall. I usually don't notice it on a cold start-up but then again, the engine overall runs a little louder at first, but by the time I get out of my subdivision and to the first traffic light I start to hear it. I really don't notice it when I am moving either with windows up or down. Again it is more of a tapping then a knocking but it's enough that even my wife noticed it when she was my passenger.

The model year is the dreaded 2003 but I had a new short block installed just 28,000 miles ago by the dealer (about 2 years ago now) due to a fairly big overheat, they also did a complete valve job. The engine has run perfectly since then and I follow all guidelines on oil changes and filters. Houston, Texas is not extremely cold in the winter but hot in the summer, I usually use Royal Purple Synthetic 10W40 and the larger K&N oil filters.

I took it to an independent shop that only does LR and the owner is a member of our LR club and is highly recommended by many of our club members as being fair, honest and knowledgeable. I left it with him for a few days and he said my transmission was a bit low on fluid, which he serviced and also did an oil and filter change as they were due. He felt the noise was no big deal and could just be normal for my Disco as it is aging. He did say it was possible that my torque converter was making the noise but he said he felt my engine was in good shape. To be honest, he and another mechanic said most car owners wouldn't notice a noise such as this but since I've had to do a complete engine overhaul once, I'm cautious.

So I feel I'm in a dilemma. The noise was definitely not there before mid January and my gut feeling is that any kind of tapping means some kind of play in moving parts; I don't know enough about torque converters other then if they fail you have to do a tranny job (transmission has 109,000 on it). But as surprising as some of the common mechanical issues with Discos are, I find it unlikely that a few mornings of just below freezing weather would trash main bearings or something else!

Suggestions or insights are welcome

 

By valve job, do you mean new valves, or just re-ground.

Are you getting any stumbling or misfires?

Does it make the noise when warm, or just cold?

 

Memory is a little sketchy but as I recall, it was new valves and some of the valve guides and it was trued up.

No misfires or hiccups or loss of engine power or performance in any way. It accelerates smoothly and the gears switch up normally.

As mentioned I don't hear it at first start up but within a mile of my house at the first traffic light that I always seem to hit on red I can hear it. And at higher rpms while driving I don't notice it either with the windows up or down.

 

open your engine compartment and listen for it. Sounds like a lifter/rocker to me and it is just resonating under the truck. I had a tick for the first couple of years with mine. I switched to 10W30 and it has not come back. I run RP and change every 3K. Some people will suggest a heavier weight oil, but the synthetics have a lot stronget film strength amd you can still have good cushion on a lighter oil that will flow better.

 

I will do a thorough inspection in a few days after a business trip and report my findings. If it is a valve or lifter noise is there a remedy? Haven't looked at my RAVE CD yet but can adjustments be made in the tappets or rocker arms?

 

no adjustments. Need to pull the rocker arms and measure the pushrods. If one is worn or shoter, replace them all. If they are ok, need to pull each lifter and inspect it and the cam lobe for wear.

 

If it is lifter noise you could drive it like that for another 100k.
Or you could have your guy tighten up the rocker arms if there is to much slop.
Personally I would just fill it with gear lube and drive it. (thats a joke guys)

There are tin "caps" in the cups on the DII rocker arms, they come loose and rattle around and sound like bad lifters.
The only 100% cure is new rocker arms.

 

I would love to see the adjustment procedure. There is nothing to tighten...

The cups are on all of the rocker arms...

 

Your right, I was thinking of the old Chevy and Ford style rocker arms.
The ones where each and every rocker has its own bolt.
We always tightened them up when they got to loose.
Ran the engine up to temp, removed the valve cover and then snugged them up until the noise stopped.

 

Or Try