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3-4 days ago I mixed EVAP hoses which i have already repaired,
today I got code P0446
TRAC OFF/VSC
And Overheating
Also I tested smoke machine and no EVAP leak
This is uncharted territory for me don't know how one would clean out coolant from an EVAP system and what the exact effects are of running coolant through a system that is designed for fuel vapour.
This is uncharted territory for me don't know how one would clean out coolant from an EVAP system and what the exact effects are of running coolant through a system that is designed for fuel vapour.
I'm on this way
All EVAP hoses is right connected
today I checked pressure and nothing leak, pressure is good,
I'm going to change Vacuum Switching Valve on the charcoal canister,
If nothing then I have to change charcoal canister (EVAP Box)
At this time I working on "where coolant going"? No leak, radiator getting empty and level of coolant in reservoir doesn't moving up or down
Coolant moves in and out of the reservoir strictly via the coolant cap (on water neck passenger side), as the engine warms it allows expanding coolant into the reservoir. The opposite happens when the engine cools. There is also a check valve on the reservoir cap but normally this is never a problem unless it gets reversed for some reason (hooked up to hoses backwards).
I think you should replace the entire canister it must have coolant in it. Isn't your loss of coolant simply because of the wrong hoses hooked up which sucked coolant out of the cooling system?
Getting to the charcoal canister is not easy. To take it out, you need to remove the gas tank (I used this method on my '02) . I have seen videos where they disassemble a portion of the rear suspension instead of gas tank removal.
Coolant Reserve tank cap assembly (16471) has a rubber hose attached that goes into tank. Make sure the hose is good, not cracked. If cracked or dislodged, it will not allow coolant to be drawn back into the system when cooling down - thus the tank will always remain at the same level. https://www.japan-parts.eu/lexus/us/...outlet/1#16471
Fill coolant directly into system show below. Engine off, remove cap, add coolant, squeeze hoses to get air out. Keep adding until full at this location
As LeX2k states above, these canisters are sensitive - coolant plus water pump pressure.... Testing pressure for cansiter diagnosis is only .028 to .058 psi.
Last edited by fortitude; May 28, 2025 at 06:46 PM.
Coolant moves in and out of the reservoir strictly via the coolant cap (on water neck passenger side), as the engine warms it allows expanding coolant into the reservoir. The opposite happens when the engine cools. There is also a check valve on the reservoir cap but normally this is never a problem unless it gets reversed for some reason (hooked up to hoses backwards).
I think you should replace the entire canister it must have coolant in it. Isn't your loss of coolant simply because of the wrong hoses hooked up which sucked coolant out of the cooling system?
I got cracked head of "engine coolant outlet flange" (very small 2-3 cracks ) and cap doesn't sitting properly, flange has not "sharp" head, I saw that when coolant getting warm leaking from that, I used "gasket maker-water pump coolant housing" I will see if it's works, if not I have to change "coolant outlet flange"
About EVAP Box first I have to change Vacuum Switching Valve on the EVAP Box, then I will see what will happen,
Getting to the charcoal canister is not easy. To take it out, you need to remove the gas tank (I used this method on my '02) . I have seen videos where they disassemble a portion of the rear suspension instead of gas tank removal.
Coolant Reserve tank cap assembly (16471) has a rubber hose attached that goes into tank. Make sure the hose is good, not cracked. If cracked or dislodged, it will not allow coolant to be drawn back into the system when cooling down - thus the tank will always remain at the same level. https://www.japan-parts.eu/lexus/us/...outlet/1#16471
Fill coolant directly into system show below. Engine off, remove cap, add coolant, squeeze hoses to get air out. Keep adding until full at this location
As LeX2k states above, these canisters are sensitive - coolant plus water pump pressure.... Testing pressure for cansiter diagnosis is only .028 to .058 psi.
Yes, I already checked how to change Charcoal Canister it's very difficult, I hope i don't have to change, because in few days I will change Vacuum Switching Valve on charcoal canister, then I will see,
About coolant I got cracked head of "Engine coolant outlet flange" 2-3 small cracks, and cap doesn't sitting properly and leaking, I used "gasket maker - water pump coolant housing" I will see if it works, if not I have to change that outlet
2002 ES300 Code P0446
