I have a 97 cherokee auto 4.0. I'm sure my waterpump is bad. My question is if I get one of the hesco or flowkooler waterpumps would I have to change me radiator cap. I don't know if the extra flow of these pumps will increase the pressure in the cooling system. My other question is I have poor fuel milage and my idel varries between six hundred and eight hundred rpm. Its almost like I have a vaccuum leak but I can't find it. I have checked intake and tb for proper torque. Do I have a map sensor and if I do where I'd it at. Thanks for the help

 

Radiator cap should not make a difference! Check the idle air control valve on throttle body, may not be working. Also start checking for vaccuum leaks and good luck.

 

Idel air control valve is the one that has the pintle that pushes the controls the throtle plate right. I just did a serch in how to clean it I think I will try that first. Thanks for the help.

 

I see no need to spend big bucks on a hi-flow water pump.

I live in Phoenix AZ, daily drive my jeep, I run a Checker replacement pump, stock thermostat, stock fan clutch and stock elec. fan and a cheap 3 core radiator... even sitting in traffic on 118* days with the a/c running I have no issues with overheating.

 

The flowcooler pump is alot cheaper than the hesco. I saw a 10 degree drop in temp when i installed one on my 01 XJ.

 

thanks for the help. my stock waterpump went bad sa i put a new one on from autozone and i cant feel any water moving through my top hose. i think its just paddeling the coolant and not moving it. i have a mopar thermostat and factory fan clutch with a 3 row radiator but its still hotter than i would like. so i will look into flow cooler a little more. i dont know what else i should check maby heater core i have no clue. last question does my 97 have a map sensor and if so where is it at i think that might be causing my bad mpg. thanks again.

 

If you feel anything running through the hose, your cooling system has air in it. The top heater hose should be really hot to the touch once operating temp has been reached. If not, coolant flow to the heater core is restricted. I used a flex nozzle attached to the garden hose and flushed the heater core by squirting water into the top heater hose (removed from the t-stat housing) and out the water pump (bottom rad hose removed). Heater worked much better afterwards, even after replacing the 195F t-stat with a 180F t-stat.