Well, the previous owner said it didn't have any current issues. We spent some time talking about the various things they had done to it, they gave me a packet of "maintenance records" which turned out to be a bunch of crap receipts from Meineke.
I drove it for about a month after I got it, when the weather was really hot (low 100's), and had no problems. Even with the A/C on. The overheating didn't start until the weather began cooling off. Strange.
I understand that it's an older used vehicle which makes it inherently risky, but it's pretty frustrating when you haven't gotten a chance to really enjoy it before it goes south on you. Not to mention the fact that I had to sell my reliable little Jeep to get the Disco. Grrr.
So put out the good vibes on the water pump. I'm going to chant myself to sleep tonight..."water pump, water pump, water pump, water pump..."

 

I think you may have gotten off to a bad start, did you not know about the Rover Gods and how you should observe certain rituals like chanting and offering sacrifices PRIOR to performing ANY work on the Discovery?

Build large fire, play loud music, have plenty of good meat and drinks. Scantily clad women dancing also helps for tthe major items. Stop theorizing so much.

SO build fire, cook aminals, offer cold beverages and arrange for hot women, the Gods will Smile Upon You. Skip these and rush into it, and you will suffer immensely. Try it.

 

....?

 

I was referring to your question to Spike about how could the water pump be the cause...........

So forget theory, build a fire, cook some animals and offer sacrifices to the Rover Gods if you want success..........

And don't forget the loud music, cold drinks and hot women dncing around the fire. Even if it does not fix the problem, it is much more fun that way.

 

If by theorizing you mean asking questions so I understand why I'm making the repairs I'm making, and spending the time and money that I don't have much of...
Guilty!

 

I think most of us are in that same boat.

It's too bad that the maint records you got were from Meinke, that would scared me off fast.

Hope you get it fixed, I hate to see anyone struggle with trying so many things and still have the problems recur.

Good Luck with it.

I am glad to learn from Spike about the water pump impeller being staked, that makes a lot more sense as to the surges you have seen. When the impeller is not constant, it would fluctuate quite a bit.

What about the radiator you removed, what kind of shape is it in?

I wonder if the LR radiator is very good design having tranny, oil, and coolant lines all in the same unit. I would prefer a separate unit for each for simplicity, just my thoughts.

 

Everything I've removed so far has had at least the appearance of needing to be removed. The radiator had a bunch of rusted out cooling fins. The bi-metallic part on the fan clutch was caked with crap, and the thermostat was looking a little old. So the bright side is, if I can knock this problem down with, say, the water pump, then I'll have a spiffy new cooling system, for the most part.
And I would tend to agree with you as far as trying to cool three different systems with one radiator. I understand the idea of less components usually being desirable, but it's also possible to overload one thing with too many jobs, and wind up with an insufficient system.

 

Oh, it sounds like you had multiple contributors that actually did need to be replaced, that is lots better than replacing good parts chasing a ghost. Keep up the good spirits and don't take my comments to harshly, they are meant in good jest. We all learn from sharing our experiences, both good and bad, humourous and down right embarrassing as well.

Best of luck, keep up the thorough work, you will eventually get there and have a great vehicle to enjoy.

 

So I just noticed a trace of fluid with a nice green sheen along the bottom of the RH valve cover, near the rear. Looking into it further.

 

Well, it looks like I somehow solved the problem, at least for the time being. I'm not exactly sure what the problem was, but one or all of the following actions caused a positive change:
1) New water pump (couldn't see anything wrong with the old one).
2) New temp sensor (didn't really seem like a sensor problem).
3) Tightened tensioner pulley lever bolt (got SEVERAL turns on it, was out about 1/8 inch).
4) New reservoir cap (probably should have done this before anything else)
5) Disconnected and cleaned every coolant connection forward of the firewall, except the throttle body hoses.
6) Another flush with 10 Minute Radiator Flush and distilled water.

Add to that the replacement radiator, new thermostat, new fan clutch and several fluid exchanges, and I really hope I can count on my cooling system being strong for a little while.

Drove it to school this evening, which is about a 20 min trip each way, mostly highway, and it did fine. Once the thermostat settled, it sat right at 191. So hopefully I can move past this gripe and get back to fixing up the odds and ends.