Prob #1
I have a 2000 disco 2. It has 170k miles but here's the deal.
It has a single knocking on the rt hand side-(lifter right?) Well thats what I thought too! so I unpluged each wire seperately and then all 4 at the same time. knocking still there. So- I thought exaust leak maybe? I havent dug into that yet...oh the cat seems fine no noise...

prob #2
I have changed the plugs and wires "not the coils" but it runs better than it did, but now Its still sluggish when I gas it "O2's" maybe? but now it is cutting out almost like its loosing fire, or maybe a fuel relay, but wouldnt the relay just go bad and not work? Im just at a loss here, It is really sluggish getting up to speed when its cold, once it warms up its fine, until like I said I gas it it stalls out then takes off. "fuel screen is in the tank"

 

that knock doesn't sound good..could be a rod or main bearing..where is it coming from..top or bottom of engine?

 

lifters tap and I'm pretty sure pulling the spark plug wire off won't affect it.

 

Not sure what oil your using but I would give 10W 40 a try and see if the oil weight can help hold what might be a colapsing lifter stay pumped up.

 

If the knock your hearing turns out to be a lifter tick, you might try lucas oil stabilizer. I've had very good luck with it quieting down the lifters in my Jeeps.

I would also suggest a mechanics stethoscope to pinpoint were exactly the noise is coming from.

 

well my thinking was that if I pulled off the plugs it would shut down the cylinder that was causing the lifter to knock. I just put some lucas in it- so we'll see? It sounds like its coming from the top of the engine right by the valve cover not the bottom so I ruled out the caps. an its either a lifter or a small exaust leak at the manifold.

any ideas on the cutting out/loosing power it feels totally like a fuel filter, but it doesnt have one except the pump screen!!!

 

Killing that Cyl won't stop a lifter tapping. That only works for rod bearing issues.

 

is your CEL on? did you check fuel pressure? did you check for vacuum leaks at the intake?

 

First, changing oil to a heavier one or adding Lucas, is just putting a bandade on the problem, you still have the problem and until you tear the valve train down and measure each part, rocker arm, rocker shaft, push rod, lifter and cam lobe, you will not find/fix the problem.

 

lifters and exhaust leaks make a ticking noise not knocking...record the sound if you can and post on here.