1999 Discovery II, 105,000 miles

First, please let me say since I bought my first Disco II in January, I haven't had to actually ask any questions here because just searching the forum has helped me answer every question I needed answered...until now.

8/27/10 - heard loud pop on the interstate, got off interstate and started to overheat. Found hose going to thermostat had hole in it. Friend of mine replaced hose, he also added coolant (don't know if he "bled" it though. Drove it fine up and down interstate every day with no problems until 8/31.

8/31/10 - while driving, power steering went out, battery light came on and heard overheating hissing noises. Tow truck towed it home. Freind over the phone, without looking at it, thought it was the belt, tow truck guy looked real quick and said water pump.

9/16/10 - After searching on here, decided to replace drive belt. Replaced drive belt (thank you to those who suggested the 36 mm wrench in the Advance Auto fan kit!) and then noticed the small hose to the right off the "T" hose connector had suddenly spring a hole, it might have been resting on the new belt by mistake.

9/17/10 - Replaced small hose to the right of the "T". and noticed coolant leaking, which was not coming from any hoses. Checked hose connections and clamps again.

9/18/10 - Disco still leaking fluids, replaced water pump. Added coolant up to fill line in coolant resevoir, did not bleed (found out about that part later in the forum and the workshop manual, not sure how I missed that the first time). No more leaks while running idle in driveway.
Drove Disco approx 1 mile back and forth. It started to feel like the engine was going to shut off while idling and had to give it constant gas to get back to the house from down the street.
Shut Disco off in driveway, popped the hood and saw the upper hose (the one that attached to the fan cowl was so swelled next to the "T" connector that it looked like it was going to literally burst any second.

9/19/10 - Read throught he workshop manual again and did a lot of searching on here and found out that I should have "bled" the system for air. I followed the directions that I believe, forgive me if I'm wrong, Spike555 posted on how to bleed air out of cooling system. First time I bled it today witht he radiator cap off, then on, then started the car. This took about 10 minutes or so. Drove around block 3 x, parked and hose was really swelled up like before. Let car cool down about 2 hrs, tried bleeding again, same result. Tried a third time this afternoon, this time raising the coolant resevoir, and still same result.

I've checked th "T" and it's not clogged at all. I've attached a few pics of the hose swelling up, this is my first post though, so hopefully I'll get it right.

Please help! I've been borrowing vehicles the whole month and I'm dying to get back in my favorite vehicle ever ASAP!

 

The reason for the hose blowing up is the thermostat is building excess pressure. Whenever it blows off you always replace the thermostat. and replace the hose and thermostat. Or else.

 

If you have overheated that engine, even once, then I bet you have more problems then needing a thermostat. I'm thinking headgaskets along with that top radiator hose and new thermostat, have that radiator checked while you're at it. Flush that block out with fresh water when you put everything back together, and add a bottle of water wetter along with the new coolant. Also don't forget if it does turn out to be headgaskets (pressure test is a reliable method for troubleshooting) get those cylinder heads to a reliable machine shop to have them tested. And I would get the valves done while they were there. But thats just me.

 

You should not have a radiator cap. How did you bleed it? If you follow the "how to" method it does not always work. You need to unclip the expansion tank an raise it up on the battery box.

 

When I refilled with coolant today, after a flush and drain, I filled with the reservoir still in place until it was full. I then raised it on the battery box (cover removed), and got several air bubbles from the reservoir, filled it with perhaps another 1/2 gallon, lowered the reservoir back into position, and more air was released. I raised it again, filled it completely, removed the bleed screw on the upper hose, let coolant and air escape, replaced the bleed screw, filled the reservoir again, removed the bleed screw, and repeated this process until only coolant was flowing from the bleed screw (a steady stream). Then I refit the bleed screw, topped off the reservoir, and re-clipped it. I started the engine, let it reach normal operating temperature, and am going to recheck the level twice a day for the next several days.

 

I am having a similar problem with my 01' D2, I replaced the thermostat with a new one because the housing cracked and sprung a leak. Now it keeps building up pressure and overheating. Would this be caused from air in the system? I have never had a closed water system before, so this kind of problem is new to me.

 

Before you guess yourself into a dead engine, send me your tele number and I'll walk you thru what to do.
In the mean time, don't even start that engine.