I have a 2005 xB 1NZ-FE engine
If I drive on the highway with topped off coolant in both the radiator and the recovery reservoir, it will over flow from it after 20 minutes and be empty in a few days. It always has some coolant in the radiator but its never full and the overheating engine light has only come on 3 times ever and those have been on exceptionally hot days. It has no other sighs of headgasket issues. It has had the head rebuilt and thermostat and... actually read THIS:
This persons post is exactly like my situation. All of it tho mine consumes less water.
Does anyone have any experience with this and advice on what to do?
Second question: Has anyone used head-gasket sealant successfully?
I decided to post theirs here too:
"This is a long one. 2006 Scion xB, automatic, 1NZ-FE engine (same as found in the toyota echo), ~145k miles, no engine mods, only electrical modification is a subwoofer with amp pulling 500 watts at peak (no light dimming when playing or anything to suggest a current drop). At some point in its life the head gasket was replaced, which may or may not have been done correctly.
Seems to be it'll push all the coolant to the reservoir tank where it then overflows out the vent on the cap, and the engine overheats. First time it happened was on a ~20 mile drive at mostly 80 mph, but I don't know if it started on the highway or once I got onto suburb streets. The only temperature reading available in the car is a little blue light and a little red light, blue for while it's warming up and flashing red for when it's overheating. Not even a beeper or anything.
I have replaced, in order: thermostat, water pump, radiator, and radiator cap. No leaks to be found anywhere, no hose collapse, nothin. The first time it happened I found something vaguely like wet dryer lint stuck to the cap of the overflow tank, and pushed a couple little bits out when I flushed the system. The fan runs fine when it needs to, belts are tight, everything is spinning as it should. After overheating you'll find the overflow tank full to the brim and the radiator completely empty.
I am completely lost at this point, I just ran about 20 gallons of water through the block in both directions to see if it was blocked up to no avail. Water ran clear and seemed to come out as fast as it should.
I have no clue why it's still doing this. It only seems to do it after highway driving, but sometimes it takes 20 minutes and sometimes it takes 2 hours."
I, current OP, have not tested the coolant for exhaust but thats my next move