Engine Overheating?

I have replaced the thermostat and also the radiator and the return where it goes into the overflow. It would not return to the radiator. I have to keep bleeding it in order to get heat and I have to drive at slow speeds in order for it not to overheat. I replaced the water pump last year. I do not know what is going on and why it will not do the return from the overflow bottle. Do you have any suggestions as to what could possibly be wrong?

This is my late father’s van that he kept garaged and maintained meticulously. I let a friend borrow it for two weeks in January in CT. He doesn’t have a garage. After about a week and 500 miles, the temperature gauge started shooting up within a couple minutes after startup. Took it to a mechanic who changed the thermostat, then the sensor, then looked at the water pump. All fine. Said he did a cylinder head check but it came out fine. Now says it has to be a cracked or warped head.

No coolant in the oil, no blue smoke out the tailpipe. Could exhaust be leaking into the coolant, creating an air pocket? Replacing the head is more than the vehicle is worth. Thoughts?

I have a 2000 chevy venture and it keeps over heating, when the light comes on, I pull over and turn it off, wait 20 mins and its cool enough for me to open the cap, when I do the water starts flowing from the over fill into the radiator, and this happens?

It doesn't make sense for the car to be over heating and for it only to take 20 minutes for it to cool down, and it worked perfectly fine all summer running the air conditioner so any help is really appreciated

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Yes I smell the anti freeze, and the person I bought the car from almost a year ago took it to mechanics all the time and they unhooked the fan, they bipassed it somehow, but it ran perfect for months and months like that

I had changed the antifreeze, radiator cap, and thermostat. The van has rear heat, I keep bleeding the air out of the system and i'm getting nowhere fast, i've noticed that there is a motor type thing or a pump to the left side of the overflow tank, I can only get it to run if I run jumper wires to it. Is this thing causing any of my problems?

Well do you know if that pump is suppose to run all the time then? Because I have noticed that there is no power to the plug on it, I tested it with a test light. Also does it run off of a relay or fuse if so where is it?

Why does the antifreeze bubble like its overheating in just the overflow container but the rest of the system is perfectly fine?

2000 Chevy venture van 3.4l still over heating, after replacing thermostat, radiator cap, fans work properly. Checked relays and all seem to work properly. Van Idles fine, then will get to normaol temp. And all coolant will go into overflow tank. Using temp gun on thermostat housing, block, water pump all temperatures seem normal (ie thermostat 180-220, water pump 150-160) not sure what to check next.

Hey Raz, sounds like he is pumping combustion gases into the cooling system from a cracked aluminum cylinder head or bad head gasket, most likely cracked head, call around and find a shop that does chemical head gasket tests, simple test to tell if there are combustion gases in coolant, it will save alot of time and money(unecesary parts) trying to figure it out.

I was driving and my serpentine belt just came off, it didnt brake or nothing it just came off. The pulleys are no longer turning and the van over heats now if I drive it. Can you tell me what cause this and how I would be able to fix it and will it cost a lot to get it fix? Thanks