sportage overheating

i've all but replaced the radiator, and its still reading hot on the temp guage. i suspect the guage but need to buy a reliable thermometer to test coolant temp. at time when thermostat opens. i did notice some other postings have similar results or troubles; such as turning on the blower motor and the temp gauge needle jumps up proportionately to the speed of the blower. i suspect a ground problem but can't be sure. the engine usually runs about middle of the guage when at cruising speeds. but temp rises when i sit at stop lights. heat from new heater core seems adequate but not overly hot especially on highest setting. i will test drive it again tommorrow after replacing the thermostat for the second time. lead to suspect overheating may have damaged first one. if the guage reads lower at crusing speeds when air flow is greater against the radiator, then i would suspect that the guage is still accurate just poorly grounded when i turn on the heater blower. this leaves me to believe that the radiator is indeed not flowing as it should and i hear that the plastic caps on the top and bottom of the radiator never seal properly after they've been removed to better clean inside the radiator. it looks like i have a plastic top. i expect another 200 dollars will cover the cost of the radiator replacement. when the guage runs hot it sits at about three quarters. i can't think of anything else? :banghead: :screwy:

so....
you replaced
the radiator
heatercore
thermostat
did you ever get to the water pump
this is what controls the waterflow in a engine
and i would also check the fan and see if this comes on.

list of replacement parts so far; heater core, fan and clutch assembly, thermostat twice, water pump i believe-my brother may have replaced it, preformed fitted hoses to the heater core, garage flushed the coolant system with pressure treatment, new radiator cap, the temp sender unit-passenger side sensor, (leaves me with replacing the guage, and the radiator)

i've all but replaced the radiator, and its still reading hot on the temp guage. i suspect the guage but need to buy a reliable thermometer to test coolant temp. at time when thermostat opens. i did notice some other postings have similar results or troubles; such as turning on the blower motor and the temp gauge needle jumps up proportionately to the speed of the blower. i suspect a ground problem but can't be sure. the engine usually runs about middle of the guage when at cruising speeds. but temp rises when i sit at stop lights. heat from new heater core seems adequate but not overly hot especially on highest setting. i will test drive it again tommorrow after replacing the thermostat for the second time. lead to suspect overheating may have damaged first one. if the guage reads lower at crusing speeds when air flow is greater against the radiator, then i would suspect that the guage is still accurate just poorly grounded when i turn on the heater blower. this leaves me to believe that the radiator is indeed not flowing as it should and i hear that the plastic caps on the top and bottom of the radiator never seal properly after they've been removed to better clean inside the radiator. it looks like i have a plastic top. i expect another 200 dollars will cover the cost of the radiator replacement. when the guage runs hot it sits at about three quarters. i can't think of anything else? :banghead: :screwy:

:grinyes: i tested the radiator with a high temp thermometer, after waiting for it to boil over the temp peaked at 185 and began cooling back down. the guage however read two marks below the red. the heater blower switch still raises the needle by one mark. probably a bad ground. this problem doesn't affect the speedometer which is in the same housing assembly as the temp guage. replacement of the guage from the dealer is 120 dollars. the napa tstat i used to replace the existing tstat is rated to be more efficient and seems to put out more heat from the heater core than before. this was a concern. problem solved :rofl:chill, its a KIA, what did u expect!

chill, its a KIA, what did u expect!

my kia used to be owned by my mom and it dont overheat. she is the hardest person on cars.

mmm... a kitchen thermometer (candy thermometer) is handy to check the temperature.
DOes it actually boils its coolant out? If not, I would not be too alarmed by the condition. ANd yes these grounding problems will jump the needle when you turn on the heater blower, the wipers..etc
But why did you change the heater core? was it loosing fluid or was it simply not delivering heat.....in the latter case, combined with the rest, all of this mess would point to one classic case: blown head gasket.