cooling problems or gauge problems?

so yesterday my radiator blew in the jeep...so i replaced it. with a new one from kragen. turns out what was in the jeep wasnt the correct one. so i now have the right radiator.

well i figured while i was at it i would replace the thermostat and gasket.

so yesterday i did

-radiator
-160* t-stat
-fel pro gasket
-new fan shroud (broke other one)
-new coolant (obviously)

so today on my way to work...cruising on surface streets the temp stays (all these are according to gauge) around 190-200*. while at a light it jumps to about 220-225*. while on the freeway it went all the way down to about 150-160*. when the lights were close together and there wasnt a lot of drivetime between them it would jump to close to 235-240*.

wtf is the deal here. is this a gauge problem? what could be causing this?

there are no leaks.

swaping out a lot of the cooling may have shown some weakness in the fan clutch or water pump. one of those things that does not show it's self untill the rest of the cooling system is taken out of the question. replacing the temp sensor would probably be the easiest thing to do. I know in 99% cases the factory gauge is more for a last resort type gauge were the acuracy is usualy only there when it ealy starts to over heat. you may want to pick up a cheep water temp gauge and see what temps that gives you...

well the water pump was just recently replaced. i know the fan is kicking on with the AC. i dont know about otherwise...

is the spring in the lower radiator hose? without they can collapse and cause flow problems

the hardline hose? or the bigger soft hose?

besthaticouldo said:

the hardline hose? or the bigger soft hose?

Click to expand...

Lower radiator hose, black rubber going from the engine block to the radiator on the drivers side.

i didnt see a spring in there to start with???

well you also had the wrong radiator before, so I wouldnt be surprised if someone did not replace it. It comes from the factory with them in it.
The dealer is your best source or sometimes NAPA has the hose with the spring installed.

would that really cause the erratic gauge temps?

whith what you are describing it sound like a flow issue. I had the same problems and it turned out to be a clogged radiator resticting flow. Just throwen out idea's.

oh ok...thats why i asked. i have no idea. i was just wondering.

Isn't a 160* T-stat too low? Lowest I've run was 180*.