pit

Last week my 2001 G/C 4.0L while driving the check gauges light came on, the temp. gauge went completely to far right and the low coolant light came on. I drove for a few miles before I came to stop after opening the hood I was surprised that no water or staem was visiable. After returning from shopping I cranked the jeep up and everything seemed normal, untill I got on the highway and it started doing the same thing. So far I have replaced the termostat, new hoses and coolant temp. sensor, the water pump was replaced 1 yr. ago. When I crank the jeep with radiator cap off the water is shooting out of the neck not burping it just shoots out and seems like there is no circulation. Once I but the cap back on the top hose seems like it fills up with air and almost impossible to squeeze. The top of radiator gets hot, the top hose gets hot both heater hoses get hot but no heat is comming out of vents only cold air. The bootom of radiator, and bottom hose feels luke warm. If I open the radiator cap when jeep is running you can hear the air gushing back into the reservoir. Total confused, Im not sure if its the radiator thats cloged or the water pump isnt ciculating. I dont see any leaks anywhere, not even the weep hole of pump. NEED HELP !!!!!!!!!

powellp

Maybe try flushing the system to see if you have some gunk built up in there. That would probably be the cheapest thing to do first. My experience has been that a water pump will start making a chirping sound when it is going bad (not always but most times).

Maybe this is a dumb question but is the system full? In the past I have been so involved in what component has gone bad that I overlook the obvious. ( I'll have to share the story sometime of how my international scout sat broke down for 2 months when it was just out of gas, DUH! LOL.)

pit

yea,i hear you Ive done that also. But I'm sure someone in this forum has experience the same issues that i have. Thanks for the info!

Mukyluk

my first step would be replace the thermostat. if that doesnt do it, do a full system flush including draining the block. if that doesnt fix it replace the water pump.
your lucky so far, when my jeep did that i immediately turned it off and pulled over but it had blown the head gasket already, ended up being a stuck damn $10 thermostat

RRAM

water pumps do not cause over heating unless they are jambed up and not turning. a bad pump will either make noise because the bearings are shot, or leak water out of drip hole because the seals go inside.
Some vehicles are really hard to get full of water because of air trapped inside the engine. I would bet its going to be your rad is either plugged on outside or the inside. Unless you have the trailer tow pack. the rads are very small. I have not worked on my 04 at all but I imagine that its not a fun time getting the rad out to check the fins for air flow problems.

pit

If I remove top and bottom hoses and run water through the top of rad water should gush out from the bottom , would this than tell me that the rad is plugged? And can I than eliminate the rad being the problem?
Thanks for all the response!

RRAM

I don't think that will tell you enough. if you have 1/2 the rad plugged it will let lots of water through, only it won't have the cooliing effectiveness that it is supposed to. the water is cooled by air moving across the . One or two viens will let a lot of water flow but will not cool it. There have times where a simple case of a new thermostat will fix the problem, but I have never been that lucky. I hope you find a quick and easy and inexpensive fix but in my experiences I have had to change or have rads flushed. Single core rads suck and Dodge has put them in way to many vehicles. But I will not start a rant on that.

pit

I guess I don't have much of a choice, right up to now its been pretty much process of elimination. So should I toss a coin heads rad, tails pump!

tsconver

pull the water pump and inspect it, sometimes the vanes will wear away and it will stop pumping. Worse you are out a gasket.

pit

ok, tails win, so pump will be first. Thanks

pit

OK, TSconver tails won it was the pump. Impeller was not turning along with pulley. Pump was less than a year old, what SH#% is out there. Water pump, serpentine belt, two gal of antifreeze & some anti seize compound $150.00, 12.99 one gal of antifreeze must be liquid GOLD. Anyway process of elimination is over.
Thanks everyone for you input
Pit