Coolant boils & steams out of overflow tube no leaks or overheating... Suggestions?
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Coolant boils & steams out of overflow tube no leaks or overheating... Suggestions?
So my car did it during the hot months of Summer and anytime I drive it for a few minutes. The coolant boils (you can hear it bubbling/boiling, etc. after driving it when parked and off) and steams a fine mist out of the overflow tube that contains the long dipstick or whatever. There are no leaks on the ground, no visible leaks on the heads, and the temp. gauge stays right below mid way like it always has. I pulled the fans and tested them, they work. I tested the relays and they work. The waterpump is semi-new, prob. only has a couple thousand miles on it if that. My guess is that it could be the thermostat sticking open and the water is not getting cool cuz it doesn't stay in the radiator to cool off. The Coolant-temp. sensor has never been replaced so it may need replacing, but it seems to work fine. Please enlighten me with suggestions. I need to know what to try first before I start spending $!
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Anybody else have something similar happen? Drives perfect no problems. The radiator cap is tight, I don't see it being the problem but I'll check again. I don't see anything around the head...The sound it makes is the main thing. I hear it when I pull it in the garage and turn it off. It sounds like I'm boiling a pot of tea under the hood. I just need to hook up HPtuners and see if the gauge is working properly and it is in fact running in normal operating temp. range. Then I'll prob. just go ahead and change the thermostat. Please chime in if you have any ideas. Thanks.
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I'd flush the radiator and change the cap and thermostat if you haven't already. A blown head gasket or cracked head/block can cause similar conditions.
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[QUOTE=jrpimp00;14225160]Had the same problem, couldnt figure it out. Tried 3 new caps, checked for leaks, thermostat, everything. Turned out when I flushed my system and the overflow tank., I hooked up the overflow tube and the head vents backwards. Problem solved.[/QUOTE
So you're saying that you hooked up a hose backwards?
I just inspected the cap again, and it does seem a little worn out and rickety, so I'm going to get one from GM. From what I read about the pressurization of the coolant, the cap increases the boiling point by using pressure, etc. etc.
So this may be the problem. Hopefully it is, cheap fix!
So you're saying that you hooked up a hose backwards?
I just inspected the cap again, and it does seem a little worn out and rickety, so I'm going to get one from GM. From what I read about the pressurization of the coolant, the cap increases the boiling point by using pressure, etc. etc.
So this may be the problem. Hopefully it is, cheap fix!
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I had that happen to my about a year ago. It turned out that the radiator fan was not coming on, and the coolant would slowly reach a boil until it overflowed. I replaced he thermostat initially, but eventually figured out that I just needed a fuse. I'd check and make sure that your fan is kicking in just to be safe; it could be that simple.
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Thanks to all for your suggestions. Prior to writing this, I already checked the fans and relays and they're all good. Looks like it WAS the radiator cap. The new one fit MUCH better and compared to the old one, it is a night and day difference as far as the spring tension and putting it on. I took her out for a nice spirited drive after a good warmup and temp. was good and she drove like a beast. I pulled her back into the garage to see if I heard the boiling sound; I didn't hear so much as a slosh of anything going on. Granted it is pretty cold here, but still I did not hear the sound nor hear or see steam of any kind so hopefully this was it. The hot months will be the telling sign, but for now I will enjoy the cold weather and let her rip!