Engine overheats, coolant level drops

I'd guess it was boiling over and shooting back in there. Anything hot enough to boil water that was heating the reservoir may melt the reservoir itself. It was probably just flowing over from the radiator.

 

is "impeller" the same as water pump ?

 

I was wondering how come the boiling water wasn't melting the resi tank. i guess it has to be made of some really temperature resistant plastic.

 

It's the thing in the water pump that is driven by the pulley and pushes the water along to create the flow.

 

The Resi tank is made to handle that super hot water/coolant. That's the only place it has to go, so it needs to be able to handle it. But, if that plastic was subjected to the temps that made the water that hot that fast, it'd melt itself most likely.

 

Lol... Mine was when I baked the tank and parts for my Harley in the self clean cycle in the oven and it locked for 6 hrs and interrupted dinner.

Then when I hooked up a 12 volt pump and used the tub a parts washer....

Too this day 20 years later I still hear about it.....

 

Once the water boils, putting more in the reservoir won't help. You have too much air in the radiator/block and it won't make enough vacuum to pull water in. When it boils, you have to let it cool and fill up the radiator AND the reservoir. And then fiddle with the upper hose to get the air out. I always run the thing, and wait until I can feel the upper hose getting hot which shows that the thermostat has opened up. A couple of squeezes and careful watching and adding fluid (rad cap open) and continue until bubbles go away. Some are VERY hard to expel trapped air (4.0 Jeep I-6 for one). The I4 I am not familiar with. The V6 is certainly easy enough.

 

One more question:

If it is either a stuck thermostat OR a broken water pump, how do we explain that I was losing water from the coolant system so I had to refill it every 30 mi ? The leak on the radiator I had (which could be not directly causing the overheating as it is a related but separate issue) would not leak out about 1.5 gal of water every 30 mi.

 

Normal once fluid expands, it will push more coolant to reservoir, which when overflows dumps fluid outside, once you cool down, more air gets trapped in engine and next time it over heats it will push more fluid out. You simply removing more and more fluid from engine and heater and replacing with air.
Normal process every car I had with stuck thermostat did this.

 

Is your leak on passenger side, back of radiator? (if thats it, its not a leak its overflow from reservoir)

 

I know I am behind the curve on this thread, but I have a question. Seems like I remember hearing that some water pumps were designed to start leaking from the shaft area as an early warning that the bearings were getting worn out. So you can replace it before it locks up completely which would shred the belt (at a minimum) and leave one stranded.

Is this the case with the Taco's? Wonder if this could be somehow related to these symptoms.

And you would be surprised how much water will leak in 30 minutes of running under pressure.

Edit, I just now saw the pics of the belt. How did that happen? Some pulley at least partially locked up for that to happen. So I am guessing you have a water pump that is now damaged internally and needs to be replaced immediately if so.

 

The loss of water is explainable- as it boils, it becomes vapor and you lose it through any leaks in the system, through the reservoir, or through the radiator cap. That would be why you have to keep refilling it- it's evaporating and you are losing it from the system.

 

The steam you see is you losing water vapor and losing water. Boil a pot of water long enough and it will be empty.

I agree that your water pump has to be toast.

A water pump does not have to be leaking out the weep hole to be bad. This only indicates a bearing failure or seal failure. Not sure what the material the impeller is made of but I had another car that the impeller was plastic. It would wear the impeller down and awhile the water pump wasn't leaking, or at a glance didn't appear to be bad. However when comparing it to a new water pump you could see the fins on the impeller were worn down considerably.

You can check your thermostat operation. Remove it, and put it in a pot of water as the temp climbs and reaches the right level it will move. Not sure what a Tacoma is, 160? 180? 200? I don't know for certain.

 

This was my first thought. The water pump, or something else which would be even more concerning since it would indicate more than one problem, locked up at that's what fried the belt. OP the water pump has moving parts. If you want to play with Wikipedia, look up centrifugal pump, and all will be clear with what an impeller is and why a pump can look fine but be toast inside.

Given the age of your truck, and your lack of experience, I would personally get professional help from a friend in person so you can learn. My second option would be to replace the radiator, coolant lines, water pump, and thermostat but I'm the sort of guy who replaces those sort of things often before they break on an older vehicle because replacing things after they break sucks..

No offense to the OP, but when you attitude is "I can do anything with the internet and time," you will end up getting hurt either financially or physically at some point. The people who are pointing that out aren't offending you. They are trying to give you solid advice.

 

And most importantly, since the OP did use the term "overheat", we want him to STOP trying to run the engine until he finds out the problem(s). And hope it is not too late.

 

Nope, but I'm more experienced than OP. If my Tacoma was nearly ten years old I would probably replace the radiator anyways while I had the coolant drained. Radiators get plugged with shit over time, especially if the pump went bad, so changing one out who the fluids out anyways seems logical enough to me.

That water pump is probably not a spring chicken either, so why not replace it when the lines are off anyways especially considering the shredded belt?

Coolant lines get crusty with age, just pulling them off a vehicle that age is usually grounds to replace them.

Personally testing everything and then replacing bit by bit over years is just asking for murphy's law to come into play.

 

I can agree with changes lines, water pump and thermostat awhile you are in there, but I don't see preemptively changing a radiator(unless it is leaking as the OP has stated) I would leave it along and just flush the system with new coolant. I only replaced one radiator ever and that was because it took a stick through it.

 

Maybe you should of read this part of my post:

Before taking offense. This website is helpful for many many things and I would never tell someone not to work on there own vehicle. That being said you are struggling with some simple concepts and everyone here trying to help you. When someone says, "maybe you should find a professional", we aren't trying to insult you. We are trying to help you. Do you have a friend or relative with some more automotive experience that can help you with the repair? You will still learn and greatly decrease your risk of injury or $$$ losses.

 

I did not say that, here's what I said.

Notice the word amount there BlueT .

Now let's see where things go with the OP. I'm still curious to see what OP's problem was and I want to see if he can solve it before he blows the head gasket trying to figure it out.

 

why dont you do a leak down test on each cylinder? also observe the spark plugs as them come out if they are wet or white build up. when pressure testing have the oil cap off radiator cap off etc probably number 6 cylinder blown headgasket. or take it to a mechanic to get it taken care of multiple overheats can cause serve engine damage. just saying