bigjeff

hey i got a 1999 jeep cherokee 4.o will a cloged heater cause you to over heat thanks

junior3382

By itself, probably not, however, if it is clogged it could be trhowing gunk that has your thermostat clogged, and that definietley would. The coolant needs to flow through all freely, but there is a by-pass for the heatercore that should allow it to stay cool.... but again, depending on why it is clogged....LOL... its easy to flush though, may help to get some crap out of there

bigjeff

i have had some brown sluge in my system something about electro but we flushed everything and put new water pump and theomstat no no heat and car is over heating i check everything again today all i could find is blocked heatercore and more brown stuff i pretty sure the head gasket is still good i need help

freegdr

more info on when it over heats will be helpful

bigjeff

when it over heats gauge goes staight to hot and red light comes on and water bubbles out from overflow allover i fushed hole system today and still doing but i did find blocked heater core

bigjeff

there is no heat i did put the theromostat in boiling water and it open i put back in cold and it closed so i now that works the water pump is 2 months old i took off today still looks new the pellers where still there

gregxgriffin

Check to make sure it's all circulating, I just had a problem with my pump that I and a few others first diagnosed as a bad core

bigjeff

water pump is brand new so if i take the top raditaor hose off and let it run water should pump out steady or what how to check if pump is working

freegdr

when your sitting idleing, running down the road ,does it overheat fast or does it gradually overheat?

bigjeff

fast like 10 15 mins

bigjeff

how do you tell if the water pump is working

bigjeff

when i am driving it will over heat bubbling in like 10 to 15 give or take i took theromsta out and put it in boiling water and it open and the real quick in cold and it shut

djb383

Sounds like both radiator and heater core are plugged.

kjc

I think you might need to do another flush or two. You need to get all the sludge outta there. One thing i'm wondering about is since you said you replaced the water pump, are you sure it's the correct pump? I think 2000 up use a reverse flow pump on the 4.0L engine. They have an R stamped on the propeller. Maybe the parts guy grabbed the wrong one. Just tossin' it out there, probably just the sludge.

rrich

Take the upper radiator hose off. Start it.
If water flows out from the radiator - it's the wrong pump..

Get an infrared thermometer - measure the temps all over the radiator Cold spots indicate where it's plugged.