P261B water pump or Thermostat?

Sounds like your head gasket has failed. I don't trust Bar Leaks. The Bar Leaks eventually clogged the water pump as you noted.

You need to replace the head gasket. Hope you have not bent a piston rod.

 

Your car is living on borrowed time. Bars Leaks is often used by unscrupulous individuals and dealers to hide defects to sell off a defective car. It never last long. If you really want to keep the car, fix it the right way.

 

White smoke is Head Gasket 101! Your on borrowed time with that motor. It's a 3rd Gen and most likely the EGR valve and an oil choked intake manifold and egr valved caused the issue.

It's a ticking time bomb. If you get the bad Head Gasket out of there, clean the EGR valve and intake manifold, you maybe able to still save the motor. If you don't and the head gasket fail's it will suck in water and bend a rod ... and that mean's new motor time.

 

At that mileage, the egr cooler would definitely be in bad shape. It needs to be cleaned probably more than the egr valve itself.

 

Hmm well you'd have to drop the oil pan to check the rod's? And that would tell you nothing, as no damage has occurred yet.

The White Smoke is the clue. The only way that can happen is if water get's into the combustion chamber full stop! Bar's leak or whatever may get you home and way work for awhile? But it is not a permanent solution.

If/when the Head gasket completely fails. If it happens at high speed, the engine will suck water into the combustion chamber and the next up stroke of the piston, the motor will try and compress water and it can't! The Rod will bend and your motor is toast.

That's a full rebuild or a new motor at the least? At this point, I would park the car and if your lucky a Head gasket is still all you need. But since you have been driving it, at the minimum you need to lay a straight across the head to make sure it is not wrapped? When you pull it off. And as long as the head is still flat and square you can still get away with a new head gasket.

And if you can't do that? A "Good Machine," can for a nominal charge if anything? But you can't keep driving it like that? The next time you start it could be the last!

This issue is that serious, your not gonna fix it with anything in a bottle, sorry.

 

Well sure the thermostat, could have failed but on a Toyota not likely? But if you saw white smoke? The Head Gasket has failed. Nothing else can do that. Blue Smoke is oil burning and white smoke is a failed Head Gasket. It's really that simple.

Heck even a compression test at this point (which could show where the head Gasket has failed) would be unwise.

 

Well if that happened last year and around June? That is freaking incredible! But that speaks more to Toyota Engineering in my view. And let more knowledgeable member's speak to codes and stuff I just know engine basics.

 

You can kill a thermostat by overheating it enough. The expanding wax blows out, and after that it won't open when it gets hot. (In fact, that's about the only way I know of to get a thermostat that won't open when hot.) So if there was ever severe overheating at some point, the thermostat should have been checked or changed at that point, lest it become the cause of repeat overheating in the future.

I guess gumming up with the bar's leak might also be a way of killing it.

Yeah, that's the water pump turning too slowly. The leak gunk could be a possible reason, I guess.

 

Most likely sure but swapping out the whole motor over a blown Head gasket is kind of overkill.

As long as the leak hasn't caused additional damage, the motor should be fine, a slow leak in a head gasket won't kill it. But a catastrophic failure of the head gasket could.

A new head gasket, new water pump, inverter pump and thermostat and now you know about maintaining the EGR system, so it doesn't happen again. And a good shop to do the work if you can't do it yourself?