Hello, my 1999 Jeep Cherokee Sport 4.0L straight 6 is making a boiling coolant type noise I believe. My Jeep is not overheating! The noise is quit loud though. I need to know what is the noise so I can fix it. Don't know if it's water pump, or air in radiator (so bleed out radiator).? Please and thank you!

 

Expansion tank, maybe?

How long have you owned it? Maintenance kept up? How many miles? How's the rest of the cooling system? Anything replaced? If so, when? When do you hear it? While running? After shut off?

Please provide details, so we can help you out. Not trying to be a jerk, but we need to know a bit more to help you out...

 

Hear it while it's running? Or after you shut it off? (Kinda normal)

 

I owned it for 2 going on 3 years. Kept up maintenance in fact just put new front rotors and brakes a couple days ago. Miles 207,000+. A/C not working heater does though. Going to fix the A/C soon. I hear it while it's running (the vehicle). Replaced a few things (A/C compressor, heater core) I believe that's it in the engine area.

Oh yeah I replaced the compressor and heater core about a year ago

 

While running.

 

Have you verified temps? Don't rely on the dash gauge, it may be faulty. Any coolant loss at all?

Strange that you hear it while running...the expansion tank is just that, it's designed to hold the liquid from the cooling system, that when heated, expands, goes into the tank, then back into the system as it cools. You will hear it operate, but normally after shutdown...

If anything, do a coolant flush, and see where you stand. If you have done nothing more to the cooling system other than a heater core, I highly suggest doing a cooling system overhaul. New rad, water pump, hoses, thermostat, cap, fan clutch...it's fairly inexpensive to do, around $200-250 for everything...these rigs need a properly functioning cooling system.

 

There is a small coolant leak not sure where exactly it's at but I've been told it's very small leak. Sorry I forgot to mention that part and no I haven't verified temps I do usually look at the gauge

 

This is why you need to be as detailed as possible. I'm guessing you don't do the work yourself. Address the leak. Again, I suggest doing a complete overhaul of the cooling system. Small leaks turn into big leaks. Big leaks = big problems

 

Nope I do it myself with help of course but had the leak since I bought the Jeep and hasn't got big nor small

 

Time for some noggin' pokin' then. Find the leak. Fix it. Verify temps with the proper tools. Time to do some diagnostics. Is the noise constant while it runs? Pop the hood and see where the noise is coming from. Verify it is coming from the cooling system. Not much more I can give you until you have some solid data.

 

Okay. The noise is constant when running. The noise is located right where the radiator is. I can hear it when the hood is open and I can hear it when close when listening in front of the grill. That's where it's making the boiling sound. It's coming from the radiator or something that's right by it, it sounds.

 

Radiator leaking?

Take it to a shop.

 

How do you know you have a leak? Do you see coolant on the ground or in the engine bay, or is it just disappearing?

Have you tried idling the Jeep with the radiator cap off to see whether it looks like exhaust gases are bubbling up through the radiator filler mouth?

 

When I get my oil changes they told me and also one time I was washing my Jeep at a self wash and I was washing the underneath and the coolant was dripping with the water underneath. It wss towards the middle though underneath. I haven't tried that idea.