Hello

My son was given a 03 Expedition that has a over heating issue. I checked the dipstick and didnt notice any water on the stick. But I am sure there are better ways to diagnose this. I also was told that intermittently a oil pressure message will pop on the little screen, but I have yet to see that. Can you guys share some methods I can take to diagnose this issue? So I can gather whether it is a head gasket or something smaller?

I appreciate all input.

 

Bad oil pressure can be a number of things, everything from worn out main bearings to bad oil pump, or simply just low on oil. The best way to diagnose that is to hook up an oil pressure gauge to take real measurements of the oil pressure. For the overheating, it could or could not be related. Unless you find oil in the coolant, or coolant in the oil, then there's less of a chance that the head gasket is bad.

 

The simplest solution is to replace the thermostat. Overheating can thin the oil and cause a drop in pressure, so the two problems might be related.

 

Does it overheat while driving or while idling?

If while driving then check the thermostat isn't stuck shut, or you water pump has frozen (unlikely).

If it overheats while idling then your fan clutch is going bad and it's not pulling enough air through the radiator.

Have you tried flushing the coolant? Looking for leaks? Start simple before jumping straight to head gaskets.