2001 Blazer 49k miles

So... last weekend I flushed my antifreeze with one of those flush kits that splice into a heater hose. I also replaced my radiator cap as the original was probably weak and problematic on hot hot days while running the ac.

I flushed the antifreeze because I thought it might be original and it looked like rusty mud.

My temp has risen to 240 on two different hot hot days with the ac running, and I think I have a clutch fan that is not locking up as it should.

Lets list the issues:
bad antifreeze
weak radiator cap
clutch fan not locking up

and.....

and.....

What happens to 10 year old hoses if you install a new radiator cap? they fail. prolly because the old cap was weak and allowed pressure to escape.

This morning on the way to work a heater hose split right wear it attaches to the nipple on the engine block, in part, I think, because I did not orient it back to the location it was before I spliced into it. I allowed it to stay out of its little plastic bracket and keep tension. And in part because the new radiator cap doesnt allow any pressure loss at normal operating temp.

I have put the old radiator cap back on. I have trimmed the bad spot off that heater hose and reattached it to the nipple. I refilled with water.

As soon as I can, Im gonna replace the thermostat, all the hoses, the clutch fan, have the radiator dipped and cleaned out, take the water hose squirter to the heater core and the engine block, refill with top quality antifreeze and then pressure test the system.

I wonder if there is a system cleaner worthy enuff to help clean this corroded cooling system... hmmm

am i missing anything?

 

Other than the hose letting loose what else is wrong? Did the 240 over temp occur before or after the flush? You basically explained why the hose failed. Im just a little confused why you reinstalled the old cap thats all.

Oh yea, I wouldnt replace the clutch fan unless its bad. Keep in mind, the clutch has to be in hot air from the condensor and radiator to lock up. If you have a plugged radiator it wont be heating the air like it should. Since the air isnt getting heated the fan wont lock up like you would think it should. It would be very easy to blame the clutch fan when in fact it may be good!

Good luck!

 

Im using the old cap because Im leary of subjecting the old hoses to the kind of pressure the new cap can hold, but this might be "all in my head"... idk.

Very good point on the plugged radiator idea, this might be the case.

 

Was the new cap rated for 16 PSI? The cap is supposed to let off excess pressure otherwise you can blow hoses or even worse your intake manifold gaskets. Most of the time a radiator will plug towards the bottom so after your car is warmed up turn off the engine and feel the radiator fins. If it's plugged it will be cool on the bottom and hot on the top.

I assume you are hitting the 240 mark while stopped at a light with the A/C on and it cools back down after you get going. If it's overheating while the car is moving you can pretty much eliminate the fan as the cause as it's purpose is to keep an air flow while the car is stationary or moving very slow.

 

make sure you dont leave that flush kit connection in the system...it will fail on you.
found out first hand.

all you other ideas sound like a good plan...did you have the passenger side higher then driver when you filled it up? this will help with the air in system.
i would agree that the core could be plugged up.