Took the disco over a mountain pass and noticed the temp gage getting really high. I pulled over, let it cool and it seemed to be fine the remaining 40 mins of my trip. On the way back, going over the pass, same thing but this time coolant started shooting out the sides of reservoir. I had no choice but to let it cool and limp home. Tried diagnosing a bit myself, but the problem seemed to disappear for a few weeks. However, on an extremely hot day last week, it happened again. I was thinking probably a bad thermostat. Where would you guys start with this? Also, is the reservoir designed to release out of the seams like that?

 

is the reservoir designed to release out of the seams like that? No, not out of the seams. Only out of the cap.

The thermostat could be bad, but more likely your fan clutch is shot.

The main question are 'how hot' and 'for how long'? The heads are aluminum and subject to warping at high temps. This compromises the head gasket. When the head gasket goes, generally, coolant is allowed to enter the combustion chamber and is consumed with the normal combustion of the engine. Sooner or later all the coolant is gone (it can happen quickly) and the engine is running without coolant. That can be fatal if it goes on for any length of time.

Change the thermostat and the fan clutch. Get a OBD dongle and an app to monitor temps more precisely than the gauge. The gauge is pretty worthless. the joke goes something like..."there are three temps on the gauge, off, on, and screwed". By the time the gauge reacts it is usually already a problem.

notes on OBD implementation..... https://landroverforums.com/forum/di...02/#post581013

 

Thanks a ton Walt. Ill give it a shot

 

I should have mentioned....fan clutches are all kinda wonky. Some engage too aggressively and continually, some don't seem to engage at all. And all sorts of variations in between.

If you want the highest level of protection and are running a stock fan, the best clutch I have found is the Hayden 2991. It HOWLS like a garbage truck all the time. Here in NYC, when the traffic backs up, the heavy duty fan clutch is needed. You may have similar needs in the summer. I change mine when the weather cools off to a standard duty unit.

 

My fan clutch will come on and stay on when the a/c is running

 

disco96sd, I think you might be referring to the electric fans in front of the condensers and radiator. The fan clutch controls the engagement of the large fan behind the radiator.