i have had my 05 hse vehicle for about a month with no issues and literally today she wants to overheat. I get out and the top hose is loose like the pressure pushed it off some and enough to leak and spray. All of the serpentine belts are good and on all the pulleys. Does this mean to go ahead and change the water pump??? which therefore while changing it then a new thermostat as well? My fan is turning off and on when the ac is running as well. I am just stuck and have no idea and do not want to get her hot enough to where I am in a worst situation. Thanks for the help

 

Whatever the root cause, I’m guessing you now have air in the system. You don’t want that.

Thing that you will need in are:

• code reader, if nothing else you can read the coolant temperature and can speed (although you can “guess” the speed based on the amount of noise)
• more OAT coolant mixed with water 50/50
• patience

Search this forum how to air the system. From experience I can tell you it’s worth to have the front of the vehicle inclined upward on a ramp or something.

I would not throw the parts cannon at the problem without first diagnosing properly.

Failing that take it to the shop, preferably on a flatbed rather than driving it.

 

My 08 Range Rover did the same thing to me last summer (same motor as the LR3). Was a 115* day and one of the crossover hoses blew off its connection. Just replaced the hose and went through the add coolant and bleed the system process and had no issues since.

The fan turning on and off with the AC on sounds normal to me. Extra load means extra heat so the fan will run more

 

ended up being the theromstat...cheaper than a water pump and blown head gasket lol

 

so as much as i thought i corrected the problem, literally not even five minutes down the road it starts to get hot again. you turn the heater on and of course, she will level out and be at half on the temp gauge. I have not added any coolant to the reservoir yet but it dow show below the cool line. what else can I check or what are some other ideas ???

 

I doubt the heater is the problem, I mean it has constant flow. More likely is that the viscous fan cools down the engine to some degree with a delay.

My suggestions are the same as before.

 

Happened to me before after filling and bleeding. Had no air at either bleeder (t on top and reservoir) but still got hot like that.

Make sure you have some coolant on you. Next time it happens, pull over and take the cap off the reservoir to burp it then backfill any coolant drop. I had to do that a couple times and it ran fine after.

 

If the thermostat really was the only cooling system problem, then you likely have air in the system still. This engine needs a really thorough bleeding process if you don't vacuum fill it. Any air pockets in it can lead to overheating. You can search to find the bleeding procedure in the forum.
How was the thermostat diagnosed?

 

themostat was diagnosed because when i took the old one out the spring had no compression , I literally had t drive about an hour out of town to pick up son and drive back home and she did fine. i just add to add som coolant and give it a good drive. so far so good