Overheating problems

[snrusnak]

Hey all, I thought the water pump was leaking on our aveo so I got a new gasket and replaced it (had done the timing belt and water pump all 10k miles before). I am still getting leaking and I think it's the tstat housing actually, it is the upgraded 2 piece metal part, not the oem plastic part, and it looks like it's leaking there.

Well today my wife says the car keeps almost overheating, but the coolant is full. I have also replaced both radiator hoses during all this work. It has to be the tstat sticking or the water pump broken right? What else could it be? It's even pretty cold out here around 50s this morning, and she was cruising at 60mph on the highway. I'm pretty sure the coolant is not circulating. Any help please, I am nearly stuck. I'm pretty mechanically able too, so I'm getting frustrated that I can't figure this out.

[snrusnak]

And how does a water pump "go bad" or "break"? Isn't it a direct shaft that connects from one side to the other, so if the timing belt is turning the pump isn't the fins on the other side spinning, moving coolant?

[snrusnak]

I did some googling and found out there is a vent/weep hole in the pump that will vent coolant out (leaking) if the pump is going bad. I have a bearing noise in this area(belt area) that started when we noticed the leak, do you think the almost brand new pump could be bad and is venting/weeping? I just assumed the bearing noise was from the leak getting on either the tensioner or idler pulleys. Maybe not though? I feel like I should just put the oem stock pump back in, even though it has over 100,000 miles on it. I don't trust another "new" one, if this one failed within 10,000 miles and is causing me so much time/trouble.

Any help appreciated. I'd hate to do the whole job again and not solve the issue. I've even thought about buying an entirely new timing belt kit with new pump and redoing it, but I'd hate to spend $200-$300 and it not be fixed. I'd rather throw the old pump in and have it last 40,000 or 50,000 miles then buy a whole new kit and redo it then (at the 60,000 mile belt interval).

[charlieb]

i think you have answered all your own questions! seems like the waterpump is failing. noise(bearing)+ leaking = failure.change out the pump.i would purchase another brand after market 1.

[snrusnak]

Is it possible for the timing belt to turn the water pump gear, but the impeller on the other side of the pump is not spinning? As in, could the shaft break? Because even with a leaking/squeaking bearing, I'd expect coolant circulation from the pump...right?

[charlieb]

heres a pic not much help though

[snrusnak]

Thanks. I am pretty sure it's the water pump seeing as I'm getting grinding/bearing noise in that area and a coolant leak (which I now think is the vent/weep hole). I think I'm going to stick the original pump back in. I don't want to buy another aftermarket one and have it fail in 5k miles like this one. The original one has no play still and no noise when spinning it, it spins freely.

[snrusnak]

The only thing I don't understand is that I would still think the water pump would be moving the coolant even with a noisy/leaky bearing/seal. Unless the shaft broke. I don't think this happened though, but who knows...

[petrified.rabbit]

it could or it couldnt. the parts could have separated, the fins could have broken off, there are a few possibilities.

some failed water pumps:

[snrusnak]

Thanks. So if I pull the water pump and it is not separated like that, what else could it be? I'm going to buy a new pump and swap it out tonight (I'm getting good at doing this procedure lol....probably only about 2-3 hours this time).