WJ Cooling Issue

[shamus275]

Hey Gents-

I've recently purchased a 00' WJ w/ a 4.7 V8 and I have this weird coolant issue that is driving me nuts! I figure there must air in the system or something because when start it or drive it and specifically when I slow down or turn I can hear coolant being forced into reservoir. It sounds almost like a toilet flushing...I know strange but that's the best way I can describe it. I've drained the antifreeze and refilled as per the WJ Jeeps website to include cranking the heater up, getting to operating temp then letting it cool down. I did this three times like that website says and I still have the same water rushing sound? Any help or ideas is greatly appreciated!

And by the way, I'm a newbie here and I'm in complete awe of some of your rigs!

Thanks!

Shamus

 

[UK4X4]

turn off ac and repeat-----

if still there check your power steering

as the rad should not be effected by turning- but the power steering will

 

[shamus275]

How would the PS affect the radiator? I'm new to 4.7's and I've only owned 4.0L sixes.

 

[shamus275]

Also, could this be a case of the radiator cap not holding pressure?

 

[Nick02]

fellow 4.7L owner here
the sound you are hearing is the coolant boiling over (230-250ish deg) into the overflow tank if you hear that STOP THE TRUCK IMMEDIATELY.
The 4.7 has aluminum heads and can WARP and blow the head gasket if you drive the truck overheating.

Does your truck ding and throw "check gauges" before it overheats?? where's your temp gauge sit when it bubbles into overflow?? If it's in the normal (gauge Mid range or below) (less then 210) (no steam coming out of the overflow vent tube or overflow cap) then you have a bad rad cap releasing coolant too early, and that's a simple fix.

if not..

#1 check your fans make sure the mechanical fan engages and that the electric fan comes on as well (on my Dakota the E-fan comes on when the ac turns on or the coolant temp is above 210) (assuming you have both)
#2 Check the thermostat, located pass lower front of engine, the therm o is in a plastic housing held in by two under designed thin screws, makes sure to carefully untighten as they tend to break off and your in deep poo, when re installing ALWAYS use anti seize compound on the threads.

MY bad therm o hardly opened.

#3 check the waterpump, replacement is only $52 at autozone
Mine had a bad seal that evaporated coolant onto the block

to burp the 4.7 you add coolant to the rad cap, while you have the vent plug removed

when coolant comes out of the vent plug you close that then fill the cap till it's full, then start the engine and watch the bubbles bubble out, when the bubbles stop put the cap back on.

hope that info helps out

 

[shamus275]

Well its definitely is not running hot so I'll try the rad cap tomorrow and then continue with your suggestions from there.

Thanks for the info!

 

[UK4X4]

Your complaining of a liquid whooshing noise - not overheating

other systems on your truck that have fluids

are

power steering
AC system
transmission
engine oil
transfer oil
axle oil
and washer bottle.

I said check with AC off as the GC has issues with the automated flow control system, little vavles and vacume cylinders " blend doors"

It is a fluid gas based system with a rad under the dash

and you hear the issue hence its either very close to you- under the dash
AC system- under the floor transmission

or its very loud

Pop the hood and have some one start the truck- wheres the noise comming from ?

with hood popped have some one turn your wheels lock to lock

low power steering fluid- causes cavitation and whooshing noises

low transmission fluids in an auto do the same

and yes be very scared about over heating

 

[Martyn]

I had an issue with the radiator on my WJ. A little different to yours but it may be worth checking.

After stopping the vehicle I could hear a sound like a soda can being opened. No sign of leakage of coolant, temps running normal. Took a long time to find the cause.

I had a very small crack in the plastic top to the radiator. It remained sealed until the vehicle was turned off, about 15 seconds later the crack would open and coolant would bleed out making this hissing noise. It then, almost as quickly, stopped and closed.

I managed to narrow the possibilities down by looking for the dried marks left by the coolant.

The only issues I have had in the 165K life of this vehicle are the radiator crack and a water pump failure. No warning on the pump failure, the thing just fell apart and nearly put the fan through the radiator.