A grand cherokee issue

[mopar0166]

My brother has a 2002 grand cherokee and it was been experiecing cooling issues.  I have already reaplced the rad, waterpump, thermo state, elec fan, hoses, belt and then flushed the engine. 

It seems to be leaking from somewhere, it can be the heatercore because there is no sweet smell what so ever in the car, cant be the head gasket or cracked block because the oil is clean/normal.

The only thing that i can think of is that its pushin the fluid back into the reservoir and coming out the by pass hose. 

Any ideas? 

[Cooter]

4.7? I assume the coolant looks/looked like river mud before the overheating issues?

Also, doesn't need to put water in oil to blow head gasket. Can be simply burning it. Swapped the cooling fan Clutch, or relay that you have to remove the entire front bumper to get too?
it is solid state, so no cleaning the contacts..

Need more input...

[mopar0166]

Its a 4.0 inline six, sorry,

Replaced the fan and relay

it seems to be losing a significant amount and once an while you see a puddle under the drivers side door

[daveco]

Fixed the overheating problem on our 2004 4.0 6cyl Jeep by adding the engine driven clutch fan. About $120 using all new parts (clutch/fan/four bolts), takes about 45 minutes. The fan assembly just screws onto the water pump shaft.

[Musicman]

You replaced the Rad but how about the cap? A old weak cap, or a new cap with the wrong pressure rating will have you boiling over early and dumping into the reservoir.

[mopar0166]

Its not over heating, but losing fluid.

now the temp guage could be shot but thats a strech

[Musicman]

You mentioned it loosing fluid out the reservoir, which usually means it has to get by the cap first

[mopar0166]

losing fluid out of the reservoir is just a guess

[b5blue]

Certain 4.0's heads were prone to cracking, check out NAXJA's forum for details. They are a great bunch of guys like here.   

[mopar0166]

thats a bummer    

if anyone thinks of anything please let me know

[Chryco Psycho]

head or head gasket , connect a pressure tester & see what shows up

[mopar0166]

We are going to do a few more tests this weekend, but it doesnt show any taletale signs thas its the head or head gasket.   

[71charger_fan]

Have you checked the heater control valve. Lots of those were plastic and got brittle with age. The crack would open when hot and close back up when it cooled down.

[covet66]

Would get fogging on inside windshield of my 2001 GC straight 6, was heater core- no coolant loss inside at all, a pinhole leak I guess. Man I love Jeeps and I guess they are no worse than others, but newer vehicles suck to work on or repair!