You could probably find some of my posts here and on the other LR site but I started out with overheating on mine and went through all the checks and finally after replacing sensors, coolant a couple of times, stats a couple of times, installing used a/c fans, checking the fan clutch, checking the water pump, and working overtime to get the air out of the system (not as much trouble if done by the book) I finally took advice from some of the others on these sites and took the radiator out to have it cleaned. Shop said it was stopped up. I was getting overheated after using the a/c and especially when pulling a load. No problems since radiator was cleaned out but I will not pull a load until end of the month and then will see. If the motor is good, gaskets good, cats good (since stopped up cats can force air back into motor), sensors good, hoses good, stat good, then try having radiator clean out. Well, that is my history so far with overheating. Now back to the latest cel and abs light after I packed rear hubs and cleaned out all the abs sensors. Life in the LR lane goes on.

 

I don't see how the radiator being clogged would cause an oil pressure light. Don't get offended but if it didn't have either of these problems before I would check whatever I did last on the vehicle. "Last thing messed with is the first thing thats bad". Could be they sold you the wrong head gaskets. It's happened before.

 

clogged radiator= engine too hot
engine too hot = thinner oil
thinner oil = lower oil pressure
lower oil pressure = oil light on

 

Engine would melt down before the oil was thin enough for the light ot come on. Remember its aluminum.

 

Are you absolutely sure about it actually melting down?

 

No, not absolutley. If I can borrow your Disco I'll test the theory! LOL! I have a friend that revently had an engine re-built and the head gasket was installed improperly it had the same exact symptoms. Just trying to give a couple of ideas to work with.