Is this a normal cooling problem?

Expensive story, and I’m wondering if this makes sense to everyone:

  1. Our 2006 X-type 3.0 spontaneously started to run the cooling fans continuously—even when the car was turned off. Since the fans normally run for 30 seconds or so after shut-off, no one noticed until the next morning when the battery was dead. Got the car to the local mechanic (not familiar with Jags) and he diagnosed the problem to be the fan module.
  2. He replaced the part with an aftermarket version; it worked for about two weeks until the car had serious overheating. The car was towed to another local shop on an emergency basis.
  3. Shop #2 said it was the fan module (again) and replaced it with an OEM part. (We also later found out that they replaced a whole bunch of other parts; hoses, sensors, virtually everything but the fan motor itself).
  4. This worked great for about a week when it suddenly had more serious overheating. We had the car towed to our trusted mechanic (shop #3; his mother owns an X-type). He claims:
    “The engine cooling system needs to be bled; if not, there is an air pocket, it will overheat and dump a bunch of coolant through a pressure valve. All of the parts are otherwise in good working order” (he’s the one who told us that the previous shop appeared to throw new parts at the problem; hoping to solve it).

My questions are:
• does this sound correct? My auto expertise is strictly with vintage cars; anything built in this century is a mystery to me.
• what constitutes 'bleeding the cooling system?" Is this an actual procedure or is it simply topping off the header tank?
• could it be that the aftermarket module was fine, and the system was too low on coolant? What would the diagnostic codes show (if anything)?
• and on a relate note, what is the proper coolant for the 3.0?

Did bleeding it cure the problem?

It means getting air out. It’s plausible. Many cars ie BMWs need to be bled; the XJS also has an issue with getting the air out.

Not sure if the problem is fixed. I haven’t gotten it back from shop #3 yet. I do trust these guys, so I am assuming that they know what they are talking about. I’ve just never heard of bleeding a cooling system and what ill effects it may have.

Just like bleeding brakes it can only help.

If the high point on the cooling system is above the points where the air con is topped up then an air pocket could develop.

Buy a manual. There should also be info in the owners handbook and service guide. My X-type is a 2.0L diesel estate but the principles are the same. Any professional should be able to identify the filling/bleed point(s), expansion vessel and atmospheric recovery tank. All these elements were common last century.

The type of coolant will be in the handbook documents and by now after probably two overheats/refills you may not be using original spec and should top up using the same as the last shop used and showed on their bill.

Did anyone check the actual thermostat? I hope you don’t get head gasket problems from the bad service you’ve received