here is the story. i am diving and i turn my ac on for a bit(i had been using the ac for the past couple weeks. i start noticing my car getting sluggish i get home and hear hissing. sure enough my over flow for my radiator is spitting out steam and boiling coolant. i cool it down and check my cap...its broken into pieces(i had this type of problem in my old honda, but i replaced the cap and it was fine)
so i got a new cap but upon removing the old one a small plastic piece went into the radiator and is still in the cooling system.
my radiator holds pressure but jumps to overheating in less than a mile.
here is what i am guessing.
A- the plastic piece is ubstructing the flow or stuck by the thermostat.
B- bad thermostat
C-blown gasket
d-bad radiator

what is the best way to go about narrowing it down cost wise???

and how can i get the piece out, will it come out if i drain it or should i flush the system??

 

for now i'd have to say either A or B, or possibly both.

Theres got to be a reason why the cap was broken, right?

 

I went through this with my 95 GSR beater. Last spring my car would run hot on uphills, or in traffic with the AC on. I had a coolant system pressure check done, which was fine-and leak down test which was also good. That left the radiator or the water pump(I already had replaced/removed the thermostat and replaced the cap). I wasn't looking forward to replacing the water pump and a few things indicated it might be working.

After one trip my car ran really hot the next morning. I added water and stopped at my friends house and noticed a stream of water was shooting 6 feet in front of the car through the cowling! So, I replaced the radiator and that was the problem for me-it was blocked somehow.

Other stuff you can look for are blocked/collapsed hoses. I had a 240sx with a blown gasket and it would overheat after about 10 miles, not 1 miles as you are describing. The coolant pressure check will tell you a lot-if its leaking in the head it can't hold pressure

 

another thing you can check out is if the car cools down when you turn the heater on full blast. If a lot of heat comes off the heater it means the water pump is pumping water through the system, and that your thermostat allows hot water to go through. You can test the thermostat function by just removing it and seeing if the car will run at normal temp.

Did you ever overheat the car, like super hot in the red for a long time before you had this problem?

 

never had a problem with it before, i am wondering if the piece that broke and went in the raiator is blocking it from flowing.
i guess i should just flush the radiator to get the piece out and just change the thermostat anyways.
and no it does not cool down if i turn the heater on, but the hot air coming out of the heater is ridiculously hot.

 

what about water coming out of the exhaust? does the oil look like a milkshake? Is there oil drops in the coolant? Does your car idle rough? These are all signs of a blown head gasket. The broken thing is still probably at the top of the radiator. For it to go past the radiator and into the engine it would have to pass through one of the little tubes which make up your radiator.

Your car could be running hot because its getting hot outside! Mine did the same thing this time last year. It would start running warm when it was above 70 outside.Something is compromising your cooling system, just when your car needs it more.

 

try changing the Fan switch sensor, the radiator cap, and the coolant!

 

oh yeah-both your fans should come on if you have the AC on. At least one of the fans will come on if the temp gets up to half on the guage without the AC on.

 

i noticed that the fans were not coming on when it heat ed up. i am going to try that.