1). my heater blows warm, cool, warm. Not hot and the vehicle doesnt get very warm while driving unless I am cruising at 75mph on the Interstate but slower highways are a problem. I have coolant. what should I look for?

2). my rear windows will not roll up or down. fronts work fine. checked fuse box, its ok. what should I look for?

3). what are typical quirks of these SUVs so I can prevent or fix in a timely manner?

thanks in advance

 

Rear windows; the cable accuators have plastic gears in them that sometimes get stripped or jammed up. I just fixed one of mine. If the window moves it all, even jerks, or if you can hear the motor engage, this is the problem.

One other thing is there is a switch on the driver's door that locks the windows from opening. It might be set to lock. I occasionally bump mine.

Heater; you may need to flush out the heater core. Also, when you reconnect the hoses, make sure the one from the thermostat housing goes into the lower pipe. That way the trapped air will purge itself. You may also have a blend door problem. That's the temperature control on the dash, unless you have the climate control with temp settings. Those heaters are a PITA to fix.

There is one major problem with the 99 to 01 4.0s. They have the 0331 cylinder head that has a problem with cracking. There are a lot of threads on the site that discuss this problem. If you start using a lot of coolant, check to see if there is any in the oil. If there is, fix it fast before it wipes out the bearings! Mine just cracked into an exhaust port and created a lot of steam in the exhaust. A new head cost me $455 and $800 labor to install.

 

NO motor engagement, they just don't move. They did when I bought it in july but now, no. I already checked the "lock" button.