When it first got a higher temp than normal I had lost ALL heat...so I added antifreeze. Didnt need hardly ne so I had the thermostat changed, which required me adding antifreeze afterward...my heat began working again..BUT. It took a lil longer than before for the temp gauge to get to 210 but it did. It will go down dramatically if i press the gas or even if I let off the gas and hit my brake to stop. Then as soon as I take off again and get to a steady speed the temp will rise right back up. I wont let it get over 210 so I dont drive but maybe 3 miles from my house for fear of getn stranded. I hear a gurgling sound like my heater core needs flushed but that could be that its low on coolant still. But with the temp gauge jumpin up and down so wildly I am starting to think that it may be something wrong with my fan instead of my heater core as I first thought. I had a friend move it the other day and he said it sounded like something was squealing and it was under the hood not in my dash like the gurgling sound. Does this sound like a fan issue or a fan issue? I am female and my ol man wont help me when it comes to my vehicle so plz helppppppppppp

 

what year is it? Matters.. but it is not the fan. It's air in your system. You need to find out where the coolant is going if it disappears. Check your dipstick or drain oil and look for water/coolant

 

Its a 95 and I aint losing coolant or water ne where. I did read on here about trying to turn my fan by hand and c if it turns easily or not and WOW one lil flick and it starting turning with NO resistance. So I really think it is my fan clutch, especially cause of the way it acts when its overheating and then not overheating and then a lil hot and then not hot and then really hot. The only thing that would make sense is that the fan isnt running when it needs to hence the clutch and as for losing my heat and getn it back that was fixed with the thermostat and adding more antifreeze when it was changed (replaced what was lost when the thermostat was pulled off). And I did lose a bolt that holds my breather hose clamp but had to drive it to the shop without it clamped down but the way it is made it is still a tight fit but will get getn a new bolt when I go to the auto store. And by all means, PLEASE GIVE ME UR OPINIONS that helps me figure out how things work and I dont learn without asking questions.

 

You need to test the fan after the car is warmed up..do remember to turn off the engine first. The fan does not do anything when you're going down the road. The air is forced through the radiator by the movement of the vehicle. The fan only helps when you're going really really slow or stopped at a light. Try "Burping" your system..do a search here on the procedure....should be lots of examples. If everything is working correctly your temp should not go up to 210 at all....especially this time of year, unless of course you live in South America where it's summer now. If burping doesn't work you may want to think about replacing the radiator. Crap can clog the lower passages so that you only have 40-50% of your cooling capacity.

 

pettyfog&dobyken are on the right track! But I would do a full pressure test then flush the system and replace the t-stat as well before you replace the radiator,but that may be where you are headed anyway IMO. Original radiator? Mileage on the unit? step66

 

I know it may be a given, but be sure and belch the air out of your cooling system. A little bit of air will really cause some temp spikes.

 

Ok..since the last post I did replace the fan clutch anddddd it was pointless in helping my problem but I hear a really loud sound now from the air it pushes thru LOL and as for the radiator, I just replaced my radiator bak in July so I know that is still good...or it better be! I think im gonna look up the procedure for burping the system to get all the air out of it and Im prob gonna go ahead and have my system flushed soon to be on the safe side. My blazer has right around 197,000 miles on it so the parts I have replaced thus far I chalk up as a lil TLC given to it while trying to locate what the real problem is. Me and the blazer have a love hate relationship, it loves my money spent on it and I hate it cause Ive spent so much on it the last few mths lol

 

I burped it...had a lil bit of air in it but not enough to make it overheat so of course I still have an overheating issue. I am getn it flushed hopefully today and if that dont work the only thing I can think of thats left is that my water pump is going out. So I am still not in any better shape than when I first posted this in the beginning...UGGHH

 

Did you flush the system before you put in a new radiator? If there's crap in the engine it can come loose and replug some of the channels even in a new radiator. Since you can't see inside the radiator the only test I know of is to feel the radiator after you've been driving. If it's hot on top and cool on the bottom then it's most likely the bottom passages are blocked. Crud is heavier than water so it goes to the bottom clogging the bottom passage first and working it's way up. A chemical flush may or may not clear it. I have, with some success, removed the radiator, plugged the outlets except for the passenger side hose and forced water through a radiator cap drilled out for a garden hose fitting. This reverses the water flow which can't be done running the engine unless you have some really long hoses.

It's is possible that you have had multiple bad thermostats but highly unlikely. It's rare for a GM water pump to stop pumping..usually they just leak from the bearing shaft. I personally have never seen a worn out impeller but I guess it's possible. There's really not a lot of complexity in a cooling system...water goes around in a circle unless something is stopping it.

 

wellllll...I did get it flushed and also replaced the temp sending unit as well and all to no avail. My coolant had lost even more circulation and frankly didnt seem as though it was even moving ne more so the only thing I thought I had left was the water pump. I was tired of screwing with it so I took it to the shop which is my go to guy and once he got the pump off he called and told me it was fine and I didnt need a new one. But he had decided to check my radiator (which I didnt consider since I had just got that one used and put in only 7 mths ago) just to make good and sure it was ok. It didnt leak at any time that is until he pressurized it and as soon as it had pressure it began leaking like crazy out of a crack in the side. I dont no how long its been crackd and had he not tested it just to b sure its untelling what else i would of replaced until the crack became large enough to start losing coolant thru. The last radiator also had to have been cracked for a while before it started losing coolant and even after it began losing it I was still able to drive it for two wks before having to replace it. so i dont no if the radiators are magical or what but I got a feeling that crack has been my problem all along, I hope so anyways since Ive been dealing with this since right before xmas.

I had it flushed last week to see if it would help with circulation since I had lost circulation over time and by looking in the radiator u couldnt tell if it was moving at all. I also replaced the temp sending unit at the same time...BUT when those didnt help at all I assumed it must be my water pump (didnt consider the radiator since I had just put a used one from a junk yard in 7 mths ago LESSON LEARNED TOO) but the pump was fine. My go to mechanic pressurized my radiator just to make sure it was ok and well...as soon as it had pressure it began leaking thru a crack that no one had seen at all and several people had tried to help me figure out what was goin on. I started having the overheating problems right before xmas so this whole time that cracks probably been there and never leaked cause it was either not big enough yet or else cause the crack wouldnt let it build enough pressure to push it out of the crack. So now Im waiting for the shop to replace the radiator with a BRAND NEW one and then see if the overheating problem is fixed. When I get it back from the shop should I flush it again or would the last flush be enough considering it wasnt drove but 1.5 miles to the shop then the new radiator put in?