Or pooped out old battery or loose connection that has a mind of it's own. You may also want to do a coolant pressure test (borrow/rent from parts store) to confirm any coolant leaks, and you can add dye, then after running engine pull spark plugs and look for flecks of green.

 

Okay, I just let it run for a few minutes and it sounded like a lifter was rattling.... It could have been knocking though bc it sounded pretty low in the engine. I gave it throttle and the noise didn't increase like a lifter chattering though.

 

in my humble opinion and having solved a long time overheating problem, having read a ton, having replaced everything in the cooling system...I am convinced radiators must be a huge percentage of the overheating problems.

the rod out Sava suggested changed everything for me. My temps are running in the high 170's usually, rarely going to 180. Yesterday after I ran it hard for an hour it climbed to 203 for a second after I turned it off. I can climb hills, sit in traffic and run my AC on high - things I haven't done in years. It's a new truck for me and there's no sign of head gasket problems for the moment.

I spent years cruising in a british racing green/white leather seats '66. Was my friends and I didn't know anything about engines so not sure how it was built but it was a great ride.

 

One thing at a time.
Correct the overheating issue first.
Motor oil that has been over heated will not protect like it should and can cause excessive engine noise.
Change the oil and filter, Shell Rotella 15w-40, 7 qts.

 

Rover quirk.
It could also be a bad multi function relay.

 

So I changed the oil with the rotella, Bosch filter, put new 8mm plug wires and normal spark plugs, put a new fuel filter on and started to take the clutch fan apart. While browsing the interwebs during class, I found this:

PartsTrain.com - Hard to Find Auto Parts and Truck Parts - Radiator - For 1998 Land Rover Discovery LE 8 Cyl 4.0L
Is this a good idea, rather than messing with fixing my old rad?

 

That depends, if you go with the cheap plastic radiator you are only asking for trouble.
Radiator Discovery 1 & 95 Classic (Genuine Part # ESR3687) - Land Rover cooling/heating from Atlantic British

Whatever you do make sure it is a 3 row radiator with brass end tanks and not plastic.

The radiator is easy to remove, takes about a half hour.

 

THe D1 rad is pretty stout, many can be rodded out and hot tanked for under $100 at an indy shop, the kind that does farm and construction gear. They don't care about the MSRP of your tiny vehicle, they make their boat payments off the big stuff. And there's always the salvage yard, but be sure to check the oil cooler side to be sure it is not blocked.

 

Pull your radiator completely out so you can take it in to get it rodded out. Like Spike said, that top one is cheap junk, aluminum and plastic, not the quality of the other ones listed or the one you have as stock.

The intermittent start on mine was the corroded ground connection from the starter to the chassis. AntiChrist makes and sells great replacement cables for Disco's.

When you drain coolant and oil, capture some to see what the old oil and coolant show you about the conditions that are present. Expect to replace all hoses, both coolant and vacumn.

Pull your plugs and see what they tell you.

 

I am taking it in the morning. 85 bucks is all! I will update how it goes.