So some of you may remember about 2 weeks ago my Disco overheated out of the blue with no prior problems with the cooling system. So I had to wait a while to get some parts but more importantly I had to wait for some time to work on it. As bad as I needed it (it is my DD) I was just to pressed. Anyway, so today got after it and replaced the hoses, the t-stat, flushed the rad, replaced the water pump, and replaced the fan clutch. Bled the radiator like the RAVE states, it ran for about 20 min in the parking lot, no problems, everything was great.

Decided to make a run to Wal-Mart with it just to test it out. No problems on the way to Wal-Mart, temp gauge stayed just below half (don't have scan gauge yet, but soon will). Got to wally world (1-2 miles from the house), parked, and noticed coolant running out on the ground. Popped the hood, boiling out of the reservoir. Let it cool off while I was in the store, come out and it won't start. So I got to do the negative lead to the frame fix in the parking lot in the 100+ heat. Woohoo!!! Got that fixed and drove it home with the A/C off. No problems and no fluid at home.

So do ya'll think it was just some more air in the radiator? What else could be causing me to boil over without an overheat? Besides getting the rad rodded out I don't know where else to go from here. The coolant that came out was not old and it came out clean. What do ya'll think?

 

Did you overfill the res? Coolant circulates through the res so I doubt it would be fresh unless a line is clogged to the res. Air in the system would cause expansion, especially exhaust gasses from a blown head gasket. Get a lisle coolant funnel and try a bleed that way while you manipulate the top rad hose. My 98 would overheat only at idle for 10 mins and was fine while driving. Coolant would come out of the res b/c it got so hot. Turns out after pressure testing I had a valley gasket leak and a clogged rad. Rodded radiator out (70 bucks) and replaced valley gasket(20 bucks) problem solved. Put a pressure tester on it and see if you see any leaks. Pump it up to 15psi. You can pick one up at harbor freight for about 50 bucks.

 

you are obviously getting pressure in there from somewhere......something is causing it to boil...i know it's a 96 but have you had the blocked pressure leak tested? after that i would move to the heads..and whens the last time you had the head gaskets done...what you described is what my 95 RR did with no fluid loss and no white smoke or rough idle...It was the heads.....

 

Napa has a block tester for 50 bucks. I used that and it did not change colors so I was lucky. I just had to figure out where air was coming in and that is where the pressure tester comes in handy. I would pressure test it and get the block tester.

 

I would scan the radiator with an IR thermometer for cold spots, I went through all the same headaches as you and that was the diagnosis for me, if I would have listened to everyone else up front and actually tested the radiator it would have saved me alot of time, headaches and money!

 

Yes, these radiators do clog easily and cause problems hard to diagnose. Removing the radiator is easy if it is clogged.

 

this is the block leak tester you would need..

http://www.youtube.com/watch?v=C2EyvgxdyRY

 

How much coolant came out? If it was only a little, and happened just that once, I would check the coolant level cold, making sure its not overfilled(or low), and drive/run it and see if it does it again.

If it was getting hot enough to boil coolant out the overflow, it should show on the temp gauge. When my fan clutch went bad, my temp gauge would rise into the 3/4 way area ideling with a/c on, and I would still not spew coolant(at full level).

Were you running the a/c when it did it? Are you're electric fans both running?

 

Thanks for all the replies guys. I will have to wait until I get back from vacation on the 23rd before i will have the money to do anything with it. I will pressure test it at that time. I was very careful on the bleed to do it just right and like I said it idled for 20 min. Yes I was running the A/C because I wanted to test it and see if it could handle having the A/C on and not overheat. Guess it failed that test. Kenk, yes both the e-fans are good. I just replaced them not long ago. (I am the one that provided the part number in the tech section.) No head gasket replace that I am aware of. I have only owned it since Feb. The PO was a mechanic who bought it used at auction, fixed a few little things, and sold it for some cash. So really no good history. No salvage title or anything like that. I believe it was a trade in somewhere, then the dealership sent it to auction. Anyway, I will post back once I get to work on it some more. Ahhh.....the joys of LR ownership. Come Feb 2011 I am going to get a Jeep to drive between LR breakdowns LOL (I know, I know, I said the J word LOL, shame on me!) but my previous Jeep was way more reliable. I love my Disco but trying to keep everything up is a pain sometimes.

 

If you're gonna be in a bi-vehicle household then at least get a Land Cruiser.

I know this may seem silly but have you checked the seal under the res. cap?