Heating and cooling issues
 

Ok so to start out i'll tell you what is going on. WHen im driving most of the time my heater blows cold. When im sitting or turn the heater off for 3-4 min then back on it will go hot. The other day it was blowing hot then i stopped at a light and seen it blow some antifreeze out of the overfill. then became cold. So my first thought was termastate. Replaced that lastnight. Driving today same old story with the heat. And when turning on the heat my truck idles down. which im thinking is either the altenater which i just replaced the belt on. or the battery cause my volts gauge does up and down with the heater on and idleing . But im still way confused about the antifreeze and why its still blowing cold. My only thoughts are Water pump is bad or it needs flushed. Oh and today it seemed like it was really hot so i popped the hood and heard a noise which turned out to be the over fill box. the radiator was blowing air into it and making it bubble. No fluid just air. with the engine turned off.

Please any help will well help lol. Is there a Dr house of toyotas on here? lol please help

My truck is a 88 extended cab 22re 2.4 , 5 months ago i redid the plenum and intake gaskets cause i had a pretty bad vacum leak.

are you sure its got fluid in the radiator?????..you say it was blowin air into the overflow..not fluid..well then your radiator sounds empty to me???

nope just filled it... and made sure it was all the way full, i did see something on here askin a simalar question and someone asked if there is as gurgling sounds behind the dash with the heater on and engine revved? there is that on mine. the guy never said what this ment

Sounds like it may be a head gasket leak allowing exhaust gas into the cooling system. Those bubbles make the gurgling sound and can blow coolant out of the overflow. Plus the bubbles in the coolant transfer little heat and thus low heater output. Pressure test the cooling system or do a chemical test on the coolant (NAPA sells a test kit for that).

X2. You have an air pocket in your cooling system. Likely caused by the head gasket, as 4Crawler explained. A pressure test works great. Pull the plugs after when the cooling system is pressurized to see if any coolant is leaking into your cylinders. Best of luck.

no muddy looking oil. so i would think that takes out the headgasket

Headgaskets don't always blow between oil and coolant passages. The milky oil is not always the best indicator, although it can be a sign.

Yep, I have had several HG leaks on various vehicles and have never had oil/coolant mixing, always an exhaust to coolant leak resulting in gurgling sounds, low heater output (those are my first signs) followed by overflowing coolant and finally overheating once the coolant level drops enough. One of those times, those symptoms were caused by a cracked head on my '85, but the other times it was a head gasket and/or slightly warped head.

I agree with all of the above. I've also had low idle conditions caused by low coolant levels. I believe the OP stated there were idle issues as well.

Yeah I would go with a air pocket in the coolant system somewhere. But also it could be your caddi converter startng to clog up or is clogged and is making your engine run hotter and overheat when your sitting still, loosing coolant through that. Just happened to my Cavi that's a 02. Flushes are easy to do on these trucks and is cheap. You have the drain on the bottom of the rad, and one on the side of the block. Flush kits are cheap.

well talked to my brother, he is not ruling out the cracked head or HG. So i ran down to the LPS and got some HG and block sealer. Which you have to drain the rad as well. so kinda two birds one yota so to speak. Hopefully that will work. Fingers crossed.

my '83 has the same problem, but only when i switch it to vent. the defrost blows really hot air, but the vent is cold, both on fresh and recirc. the heat control works on the defrost too.