alright guys/gals here it goes,

I have a 1989 cherokee I6 that overheats when I am going over 60MPH.

I have replaced the thermostat, radiator, water pump, and hoses (installed new bottom hose with spring)

I burped the system last a week and it worked great until yesterday.

I drove from Richmond to Virginia beach (about 2.5 hours) and after going through the hampton roads bridge tunnel (2hours) the temp started to rise on me again...

on my way back to Richmond everything was going great until I hit 65MPH.

I can drive Patsy all day long below 60MPH and the needle doesn't go past 210.

after i burped the system I could go 75MPH and it was ok.

I got a good week out of the burp. could there be more air in the head...
WTF... I am about at witts end with this Jeep

Also as soon as I start to go around 45 to 50mph the system cools down. WTF..

when it starts to overheat I turn the heat on full balst and that doesn't do anything but make me hot and frustraited....

I have neer let it get to the RED as soon as the needle hits the last line before the RED I lower my speed and it cools to 210 and then I will drive faster and the temp will rise again and I will slow down.

I hope this is enough information for someone to help me out...

help save my Patsy she is pretty when she is muddy and doesn't stink. She also looks good sitting on the beach in the OBX.

thanks

 

U ever solve this???

 

is you aux cooling fan coming on when vechicle starts getting warm

 

Yes fans work fine. Noticed that upper radiator hose bulging next to tstat housing. Where is my restriction? In the block? Water pump? Radiator? All the above?

 

May not have a restriction.....how old is the hose?

 

I guess I can't say for sure with our I6s, but I know with my old Subaru H4, when it starts to overhead at highway speed, it's the indicator that a head gasket is blown.

 

It has something. Gettin hot at hwy speeds. Bad hose wuldnt cause this would it???

 

Overheat at speed could be bad rad, water pump, condenser fins plugged with mud/crud, crud between rad/condenser.

 

I have a new oem rad and duralast water pump. Gonna putem in monday. See what happens. Thx for all the help.

 

ive seen old hose suck shut causing a circulation prob

 

it is very possible theres still air in it being a closed system it wont push air in to the overflo bottle as normal systems will

 

The only areas that will cause this is waterpump, thermostat, fans, or head gasket. When minw over heated on highway it was my head gasket exhaust getting in the cooling system causing me to heat up but at idle it would run perfect. Hoses will not cause this issue. Hope this helps

 

if there is a blockage in the system, a weak hose can be sucked shut causing loss off circulation until the suction of the water pump is reduced by lower rpm then the hose will return to normal shape

 

The inlet hose to the water pump has a wire "spring" in it to keep it from collapsing. The hose is the least of your worries if a scenario develops where the water pump can pull enough vacuum to "suck" a hose closed. If there is a blockage is the system, the blockage is the problem, not the hose.

 

I have a 91 that had the same problem. It was the head gasket. Very minor leak, but was the problem.