I have a 1997 Land Rover Discovery that has had issues with water boiling over reservoir cap and over heating. Replaced thermostat, reservoir cap and does not over heat now but, still boils in reservoir tank and gurgle sound coming from passenger dash area. It leaks from the front passenger area too. It then starts to knock and when I get it home I check and water is empty in reservoir tank even though I replace it whenever I have got to were I am going. It also has the ABS light on at all times. What is the problem? One day we had freezing temps and I drove to work with the heater on and I heard a loud rushing sound like something had gave and since then it's been getting worse with all the issues I've stated above. Help please...

 

blown head gasket?
cracked block?
is water leaking into the cabin? if si heater core
bad hose?
leaking radiator?
water pump?
thermostat?

the rushing water sound is because coolant is to low and there is air in the system.

check the oil see if theres water in it
if you keep running it till it knocks the oil is getting too thin and can/ will cause severe engine damage

 

If its not a head gasket:

Then you need to fix the leak. If the cooling system can't build up pressure then it won't be able to increase the boiling point of the coolant that is in the cooling system. The noise you heard was probably coolant/water running into the heater core cause it was empty. Fix the leak then, bleed the system well, should fix it.

 

You loss of coolant over a short period, and overheating, indicates a serious problem.

1. The noise under the dash is bubbles in the coolant. Could be air, could be exhaust gas from a leaky head gasket. There is a chemical test (around $60) that you can buy that will atach to the coolant container and change color if exhaust gas, which is almost always head gaskets.

2. The knocking can be your engine so hot that oil is thinned out and the engine is suffering. Can also be pockets of steam in the cooling system, perhaps from a cracked block. If steam pocket gets so large it traps the thermostat, the engine can really overheat.

3. Normally a leaky head gasket will go internal (into cylinders, makes white smoke out the exhaust); external (makes drips on the ground, can be found with a rented cooling system pressure tester from parts store); or into oil (makes dip stick read higher than normal and oil looks like a milk shake). Gasket can do all three.

4. If you put right front tire up on a curb, or ramp, or even a hill; the right corner of the evhicle is higher, and you can open the radiator vent plug, fill with coolant, idle, rev up slightly for spurts, until no more bubbles, then close up the radiator vent. The purpose is to get bubbles out of the system.

5. Temperature should remain constant. Problem with D1 gauge is that it shows "normal" over a very wide range, and actually does not show over heat until well baked. A scanner or Ultra Gauge can show the real digital temp. You would want to have a 180F thermostat installed, spring end goes inside the block. No point continuing testing if temp climbs past 217, no need to go to 240 and beyond. My 97 runs 180-187 with 180F stat. You are really overheating if gauge goes above 50%, no need to go all the way to the end.

6. Neve hurts to check fan belt route, in case some one has the water pump running backwards.

7. Don't drive truck except for testing in this condition, more damage can result.

 

Thank you all so much! I have someone coming to help me on Saturday and hopefully there is no damage to the block. I appreciate all of your help.

Tom, the thermostat had been replaced and no water is leaking into the cabin but, I will check everything else you guys/girl have told me. Thanks again!

 

Boiling, steam pressure, rock hard hoses - these make one think about head gasket or cracked block. But I had similar issues, not as much coolant loss. Turned out to be the following:

Serpantine belt routed wrong
AC condenser fans replaced and wired to run backwards by PO, subracting air flow at idle.
Bad thermostat.
Radiator sludged up.
Water pump wobbling and worn out.
Fan clutch freewheeling.

Just saying you can have multi-problems on a cooling system.

 

Mine ended up being a clog radiator and bad lower hose

 

wish I could find a place to rod my radiator would be nice to have it done while I have the heads off

 

Ask the construction equipment repair or rental place who does theirs.