Malibu overheating. Any other suggestions?

tatiana0825tatiana0825 Member Posts: 1
edited February 2016 in Chevrolet
I have a 1998 Chevy Malibu. My FIRST Car... The very first thing that happened is my heater stopped working then my car started overheating and leaking. I was advised that it was my radiator. I replaced that with a brand new one and it still overheated. The mechanic then told me it was a cracked head and told me the simply way to fix it was to put some radiator and gasket sealer so I did that. After this my husband noticed that the fans weren't working so the mechanic came by and quickly got them working again, but there was still no luck. I had another machanic work on it and he said it was the thermostate, we did not replace it with a new one because he said that if he cleaned it and made it come back open that it would be fine. He also just replaces the coolant temperature sensor. He then said it was the water pump that wasn't working so he went and got a used one cleaned it up and put it on. Still nothing!!! Some then he says that my radiator cap was not put back on when I got my radiator replaced. It does not leak as much but every so oftenit does. I also see a small puddle alot of times after im parked somewhere. So he said he fixed that. Now The engine itself does not get hot but the tank that I put water in does, it boils and I can only go so far until it really needs to be refilled it starts smoking on the right side where the water goes. Now the mechanic is saying that it is my heater core, and my fans still don't consistantly come on. Every now and then when i'm putting water in it one of them may be on very rare though. I want to know if there are any other suggestion before I get all that work done.


  • 93tracker5spd93tracker5spd Member Posts: 194
    Hello! I just found this post, I see it is five days old, but hope you are still checking it. I am sorry you are having such a nasty time with your first car. Now, let us take this one step at a time. First, the heat stopped coming out of the vents and you had cool air, is this correct? This means that for what-ever reason the coolant has stopped flowing through your heater core, this is due to one of five reasons: low or no coolant in the system, low or no pressure in the system, a thermostat that is stuck closed, a coolant pump that is not pumping coolant through the system, or cooling fans that are not working correctly. Of course I don't know how mechanically savoy you and your husband are, but these things can be diagnosed by the two of you without spending a lot of money for someone to try things until he or she finally hits the right cause. Now, if the coolant is boiling into the overflow bottle, this means your system is either badly overheating or not pressurizing. ( The purpose of the radiator pressure cap is to keep the hot coolant from boiling, when under pressure, liquid can be heated above the boiling point and still remain stable. ) Your system requires 15psi to operate correctly, that means that on your radiator cap it should read 15psi, if it does then move on. Next with the engine cold loosen the radiator cap to the first catch where it won't pull off but will wiggle, (not tight). Start the car and let it warm up, get an infrared laser thermometer and check the engine temp as it warms up, at 195 to 198 degrees Far. the thermostat should open and coolant should flow through the system, with an old towel folded double over the radiator cap, (don't get the towel into the fans) press down and turn the cap and remove it, (carefully and keep your face back from it in case coolant splashes out). With the cap removed, have your husband throttle the engine just slightly to increase rpm. now carefully look into the radiator fill hole to see if coolant is flowing through there, if so, your thermostat is open and the coolant pump is pumping. At this point return the engine to normal idle and replace the cap tightly. In a few more minutes the cooling fans should come on, keep checking engine temp with your infrared thermometer; if the engine reaches 210 degrees Far. and the fans still have not come on, the electronic thermostat that controls them is most likely bad and would cause overheating. However this would not directly cause the lose of heat in the cabin, but if coolant is leaking or boiling out that would. If you have already replaced your radiator, that part should be good, pay close attention to the pressure marked on the cap; this is very important, and when parking at home for the night, put a large piece of cardboard under the engine and radiator area to see if you can determine where a leak is, a leaking coolant system can cause many problems including lose of pressure in the system. Make sure the coolant system is full to operating spec before doing any testing and be very careful, no kids in the area and focused attention, do it together, never work alone; two heads are better than one, etc. etc. (and safer). Good luck and post back with results, we will try to narrow this down.
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