Gen 4 into Gen 3 swap fail

That bleeder (on the cars that even have it) is at a height where you don't really get any coolant out while you're filling until the degas bottle is just about full to the B line (which is the line you only use when filling and preparing to burp).

In the prescribed procedure, all of this is done with the engine off. You close up the valve and cap the bottle before starting and warming up the engine. So ordinarily, steam is not a thing you get out there. Simply some air, until a bit of coolant comes out nearly the same time you hit the B bottle line, and then you button both things up and start the engine.

So it is rather different from the inverter coolant bleeder, where you do attach a hose back to its reservoir, and keep the valve open with the pump on, and watch some coolant go through.

And on the cars that didn't come with the bleed valve, you don't use the bleed valve, and the degas bottle still ends up doing what it's there for.

 

Yes that's the one I can't remember the fella's name they're all South American great people had no problems matter of fact the owner was out of town when I arrived His workers did a bang-up job that battery still running perfectly.

 

Was just up that way last weekend

 

it is my experience that the air gets stuck behind the thermostat not allowing the impeller to do its job like a dry pump it will never do its job if it can move water. with that jigle pin being the linch pin for whatever reason removing it allows water to get to the impeller and allowing the thermostat to open else you get to install a new pump due to melted impeller so for me I will cut it and move on.

you will not get coolant out of the valve unless there is pressure so ensure the cap is on the reservoir tank Furthermore you need a clear hose all the way because if you open the bleeder valve and there is negative pressure you will do the opposite and suck in air. having a clear hose will let you know if coolant is coming out if not you are FOR SURE SUCKING IN AIR. get a clear hose drive the car monitor the temp and come back temp around 185 should have built up enough pressure to push air out. Rinse repeat. never leting the coolant with air bubbles go back in. the key here is to get coolant to come out with no air. I did this about ten times now car gets to 197 to 199 and back down depending on load. should not go above 203 if it does turn on ac button it kicks in cooling fans get back home and bleed again till the car does not go above 203. At 203 it should sit there for 10 seconds and go back down if all is working as expected.

 

I'm guessing you've looked at the bottle again and noticed there's a B line that is a ways up above the FULL line, and yes, B is where you fill to when you're doing an initial fill. To see anything dribble out that white valve, it has to be filled about that high.

After then closing the white valve and the bottle cap and running the engine several minutes past warm-up, the extra coolant from FULL to B will have traded places with the remaining trapped air, and the fluid will end up down at FULL with the air above it in the headspace of the bottle. (It will seem above FULL at first because it all expanded when hot, but when you come back and look after everything is cool, FULL is where you should see it.)

I don't think you need to drain everything and start from scratch. You can top up to B and go from there. Worst case, because your efforts to this point may have removed some of the air already, you might find the level hasn't gone all the way down to FULL when you're all done, but as problems go, that one's survivable.

With the degas design, Toyota has added some hoses to do a lot of that for you. They're the blue ones here:



As you can see, they come from strategically-chosen high spots at the engine outlet and radiator, and run back to the top of the degas bottle, which is how whatever gas bubbles are in the system end up back there, and that's happening every second the cooling system operates. So that's why the whole gist of the burping process is just to start by filling a bit extra high, then warm up the engine and run it a few minutes past warmup and let it do what it does, and hey presto, the air's in the headspace of the bottle where it belongs.

There's one more little high spot in the system that hasn't got a blue hose from it, and it's that ∩ bend where you've got the white valve there. So by fussing with that valve you can get a bit of air out there.

But it's worth remembering that Toyota didn't even need a year to realize they could leave out that valve and have their degas system still do what it does. It's a high spot, but it's also in a narrowish hose. If you think about air in different-shaped passages, if it's in a broad one it can just kind of stay put at the top while liquid circulates beneath it (just like it does in the headspace of the bottle), but if it's in a narrow tube the liquid flow carries it along, which is how even that bit of air can still find its way to a blue hose eventually and back to the bottle.

 

Just like they knew what they were doin'!

 

Ah, so the mystery isn't just in how to fill it.

What kind of sound was the water pump making? Did you get a recording? Will it make it again?

The water pump is variable-speed, and if the engine's overheating it will be running flat out, definitely louder than normal. Could that have been the sound, or was there something more horrible about it?

 

I have serious doubts that filling is the explanation. Been happening too consistently to people doing this mod.

Based on the earlier experiences, I suppose the suggestion is going to be to get at the thermostat and cut out its jiggle pin, and maybe that will get you driving, but I'm already on record guessing that's no more than plastering over whatever is really going wrong with the mod.

 

No. It may be hard to see (or even reach) because of the way the thermostat is built into the elbow. There is normally a small hole in the rim / crown of the thermostat, with a little, bitty, jiggly, pin in it.



Its whole purpose is just to give air somewhere to go while you fill. It's definitely not there to solve overheating problems while the engine is running, but a practice of cutting it seems to have sprung up among people doing these swaps. It really sounds to me like the kind of thing a person does instead of finding a problem ... but then I've not done one of these swaps myself, and I've never seen an actual detailed diagram of the plumbing and hose routing that somebody used when they did.