Yup. So after about a week or so of running fine, it got really hot the other day. I'm talking about into the red zone on the temp guage and the coolant level guage comes on. Okay, fair enough. The coolant level is a tiny bit below the "full" when cold. I filled up the coolant, cranked it up, cracked the bleeder valves and sure enough it's bubbling. But I mean it there was a LOT of air in the system. I kept cracking the valve and filling coolant until the air stopped flowing from the valves. I went to school and it was still running hot. Later in the evening it actually was cooling way more than normal. I'd never seen it at the half way mark when idling. This morning it was running alright and even when i got home in the afternoon. But when I went to school again it was heating up a ton. Pulled over, the coolant level had dropped so i filled it up and cracked the valves. Again, tons of air. The night before I put a piece of cardboard under the car and there wasn't a drop on the cardboard. Air is getting into the system somehow. I"m also concerned the fans may not be kicking on. Any ideas?

EDIT: I did a test. Car was off for about 30 minutes. Checked coolant and bleed valves and no air. Took around the block until it heated up to the red zone. Popped the hood and first bled the upper radiator hose valve, clear liquid no bubbles. Cracked the valve on the water block and hissing (bubbling) hot coolant comes out. Besides checking the hoses, anything like the gasket on the waterblock?

Thanks

 

are u getting water inside the car on the passenger side floor? that coolant has got to be going somewhere. u are going to need to do a pressure test on the cooling system.

 

Well I saw it leak...kind of. I wanted to see at what point air gets in the system. So I did the same thing, made sure no air or anything when I first started it up. Occasionally I cracked the bleeder valves and they were still good. Then being a dumbass that I am, I put a little too much coolant in. When it got to 240* the system cycled coolant and it surged over. The level remained constant. When I cracked the bleeder valve on the water pump, lots of air bubbles came out like before. The passenger area is not wet or anything. I'll check again to see if I missed a leak spot.

 

well ull need to do a pressure test to see if u can find were the water is going. beginning to think its a head gasket or cracked head. have u check the plugs for water or dis coloring. compression test would be a good thing to do for info.

 

for sure do the pressure test. only other thing i can think of is its losing it when your crusin and its pressuring up. by the way before u get to down first make sure the fans are coming on. should come on at about 210 and go off about 190 and if u turn the air conditioning on one of them should come on.

 

Craby is right, a pressure test should be your first move. Also, you may be getting an air pocket stuck somewhere with all of the refilling that you have been doing. Try starting over by bleeding the cooling system with your car parked on an incline or on ramps so that the radiator is higher than everything else- have heat on high as well. This really helps bleed stubborn cars. Hopefully it isn't serious, good luck.

 

First off, I agree with everyone else about getting a pressure test done. Second, pray the problem is not a cracked head or head gasket, like craby said.

Before you do anything, ensure there is no coolant in your oil. If there is, your engine is headed for imminent death and you should not drive it again until it’s fixed. Craby said you can check the plugs for coolant. Another way to check according to 2CARPROS, is to look for coolant in your oil by opening the oil cap when the engine is cold and looking for a light gray or milky colored goo (see http://www.2carpros.com/first_things/why_is_there_coolant_in_my_oil.htm

Ensure the radiator cap and all connections are sound. Check all of the hose connections in your radiator, water pump, thermostat housing, etc. Don’t forget to check the low coolant level sensor. It’s secured by a wire wrapped around it and as pressure builds in the system, it can begin to push the sensor out (this happened to mine). Also, ensure you have a good 18 psi radiator cap. Last of all, check the outlet hose that runs from near the radiator cap to the overflow tank. This hose runs under the battery and according to the shoebox website, the battery acid can create a hole in the hose that will be hidden from view http://shbox.com/1/4th_gen_tech2.html#low_coolant_lamp. A pressure test will detect any of these issues.

As for your fans…Is the problem that your fans are operational, but the computer is not turning on the fans when it should? Or, are the fans simply broken and do not turn on even if you power them directly? Do you know how to test for these things?

 

Sounds like what happened to my 03 Impala. It had a bad intake manifold gasket issue. The coolant was leaking into the oil.

 

I haven't had the time yet to do a compression test. Can I pick the tool up from Autozone? Also this morning I found a large puddle on the passenger side. Thought maybe it had surged but I couldn't really tell. I looked at the engine oil and it appears to be fine, I didn't see any weird discoloration. I will try to get pressure test done today.

As for the fans, after what you said, they definately aren't coming on when they should. They come on (usually) at about 240 and it drops down to about the half way mark (200?). On one rare instance I saw it actually cool like you mentioned, but then it returned to how it normally had been cooling.

 

were was the puddle located?