my 1989 iroc 5.0 runs cool(180) on highways. in stop and go traffic it runs between 220-240. never under 220. goes up to 240 and then (I THINK) the second fans kick in.

IF I RUN WITH THE HEATER on HIGH(only high) it runs 180-190 at ANY SPEED!

WTF?

 

The heater core is nothing more than a small radiator. Running the heater is a way to compensate for an inadequate cooling system--fix your cooling system. It looks as though a manual fan switch would help.

 

I forgot to add:

New hoses aready..1 month ago..
New coolant same time..

thermo.. never changed.. but i seems to be kicking in at 240..
when is it supose to kick in anyway?

i will change the cap tommorrow..

 

that is 100% true. its also a trick to use when n hot days and it wants to keep over heating. also it has saved me a tow when my radiator had a leck in it. just ran it on high and got home suck that it was 100º out that day

 

well at least your highway temps are where they are suppose to be at.

sounds like you are having fan problems, the drivers side should come on first alittle over the 225 mark. and then the aux. should come alittle ways later past the 235 mark.

sounds like the passengers fan works right, but the driver side doesnt seem to be working from what you wrote down.

the drivers side fan uses the coolant temp sensor in the front of the block/manifold area.

 

i better check my connections! I think i saw the DRIVERS side on first and the PASSENGER side go off and on at times.. ARE MY WIRING CROSSED?

PRIMARY -should be on the passengerside?
SECONDARY- should be on the drivers side?

 

drivers side = primary, passengers side = aux.

 

well i let my car idol for awhile,i actually had to drive it to get the heat high enough so the FANS kicked in...


It runs cool when driving.. The primary fan kicks in at about 225-240, the secondary kicks in at 240 or when i turn tha A/C or heater on.

it runs between 225-240 and never stable. It goes up to 240 then the fans kick in, then cools down to about 225(fans shut down)- then goes up and the fans kick in , etc...

I WANT TO run UNDER that 220 line like it USED TOO! what is going on?

PS.. I LIVE IN HAWAII .. SO IT IS ALWAYS HOT OUTSIDE.

 

check the coolet/water mix with a tester. i bet its off. also try looking at the stuff that you can add like 40 below i think its called that makes it run cooler