coolant leaking just from overflow tube on expansion tank
 

Hi guys, pretty new here but Ive read a ton. So I have a 99 disco 2 117000 miles, everything seems solid, but I have a small coolant leak from the overflow tube on the top of the expansion tank. Doesnt happen all the time and I just have to top off the coolant a cup or 2 every week or so. Checked over the whole engine no signs of coolant anywhere else. Had it checked by an indy mechanic in town said he couldnt see what the problem was and to just keep an eye on it. Ive read around here and figure it could be air in the system or possibly a stripped expansion tank cap. Anybody have any experience wuth these symptoms?

EWATK, I'm experiencing the same thing on my 2002 II se w/ 75,ooo miles. I don't have an answer but I want to share that I see the temp guage go to the upper third of the indicator( not in the red) once in a while. I'm wondering if the head gasket is occasionally leaking? Thanks

you have a coolant leak and your coolant is boiling over, get a pressure test and see if they can find it. Also if your needle is in the upper third of the gauge your engine is already severely overheated and you are going to kill your engine soon.

I have just starting experiencing the same thing, when idle it is fine, as soon as I put the revs upto about 2-3k it starts to heat up and rise up the reservoir and start dripping from the overflow pipe, I have tried to bleed there seems to be no air. Would it be head gasket?

Hate to say it but if you have read a lot on the D2 then you know that at 117kmi if the head gaskets haven't been done yet then......
Like lipadj46 said, get it tested. Or you can go to NAPA and get a block tester kit (part# 1007006, about $45) and check it yourself.


Head gaskets don't occasionally leak. They just go bad. You may have an air pocket or sticking thermostat. Replace the thermostat and bleed the system properly (there's a "how to" on this forum).


Eric

I'm confused. Coolant is boiling because of overheating somewhere in the engine or because of trapped air, right ?

In the beginning, If you kept the system topped-off even with a small leak you should avoid the current problem ?

Francois

When ever you are blowing coolant from from the cap area, assuming the cap is good, then you are over heating, be it because of a bad t-stat, plugged radiator, failed fan or blown head gasket. This needs to be found and fixed ASAP or you can toast your engine.

Holy cow, welcome back mike. Just to expand on that. The pressure along with the solute dissolved in the water (ethylene glycol) is what raises the boiling point of water. If you have a leak your system is no longer pressurized and the coolant boils.

I've replaced all the hoses, throttle body heater plate, water pump in the last 8 months. Drove about an hour no more the 50 mph, thermostat stayed at 3/4 never getting into the red which is temp it normally runs at. I did not used the AC. I parked it about an hour, went back outside and there is a significant amount of coolant on the ground that appears to be coming from the overflow tank. any ideas?

Start a new thread in the D2 section.

If gauge reading that high too high. Either it's not reading correctly or your temp is too high. Do not continue driving D2 unless gauge shows normal.

Ensure cooling system is serviced and bled of air. If coolant coming out of overflow tube and reservoir/fitting for hose not leaking replace the cap and get a reliable way to monitor your temps such as a OBDII ScanGauge or UltraGauge. Those are at least some of the first steps.
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