So i get a call from my sister in law saying on her way to work the jeep started to overheat and the heat is blowing ICE cold. Also has no Check Engine light on. Need some help where to start looking.
Bad heater core
Anything but that 
not how i want to spend 8+ hours
Doubt it’s the heater core. Would have had coolant all over inside the cabin. Check if there is coolant in the system at all. Likely it all leaked out, fill it up with water, find the leak, repair what’s leeking, then put the proper coolant back in.
Going over now to take a look
Just got back. There was zero rad fluid in there. Filled up with proper coolant just bc its getting cold and didn’t want to use water. Filled it, left the cap off the get air out. Ran the car and drove it for 20 min. Needle never left 1/2 way and heat was hot. Looked for leaks multiple times. Oil looks good, nothing out the exhaust. No sweet smell in the cabin. Ill be checking the lvl for her every day all week. Where did all the coolant go?
Head gaskets
But oil is clean, and there is nothing blowing out of the exhaust.
Then magic
Thats what I’m thinking.
Maybe a real slow seap like the intake manifold gasket where it is a little hard to find and it just leaked out slowly over time.
Coolent fairly leave any spare change in the ash tray?
EDIT: Center console… ** What cars today are made with ash trays???
What’s a coolant fairly?
Yea I’m thinking a real slow leak. Ill be checking it every day for her see how much it loses. She said its never been checked, so thats 4 or so years.
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My bmw still came with one and its a 02. Was filled with coins and some candle wax when i bought the car 
These tend to crack the radiator at the top seam all the time. It had to go somewhere
I’ve had coolant leaks seem like phantom leaks on cars before. Usually around some rubber seal that only leaks at the right temps and pressures. A pressure tester helps a ton.
Leaking from the water pump. Cleaned the engine with some degreaser with other day when I was gone. Today I went over to look at on the right side of it there is a puddle in one of the screw grooves and the over flow is down about a inch. Ill be doing that next weekend. Anything else I should replace besides the belts also?
Might as well do a thermostat while you have the system empty
Its alrdy on the list. Esp at only $25.