Dielawn

Yeah you should start by "burping" your cooling system.

DMcGarigal

First of let me say thanks to everyone who has replied, its greatly appreciated in my time of need .

The head gasket has only failed once, sorry for the confusion, if its failed now this would be the second time, in about 4000 miles, the head bolts were retorqued once already to proper spec, cant remember off the top of my head what that is.

Trust me the last thing i want to do is have to replace the head but i'm running out of options. Duplicating bubbles i mean i cant reproduce the symptoms unless i've driven it for 30 minutes or so. I tested for gases with the color changing liquid but im wondering if the exhaust gases are only leaking through at high RPM under load (i.e the highway) hence why i cant get the bubbles or gases in the driveway with the tester on.

Anyone know if the prestone rad cleaner will dissolve solid debris or just helps clean out sludge? Last flush i used just water and didnt see any sludge or discoloration, just some solid white crumbs course sea salt looking things, and a few pieces about the size of a pencil eraser. And im wondering if i was able to find that how many other pieces are hiding in there? deffinitly big enough to clog the rad, and or water passages in the head. I burped the system a bunch of times after that as best i could with the front end uphill. I am noticing that the heater hoses heat up a lot faster than the rest of the hoses if thats a clue for anything?

wallytoo

iTrader: (1)

i'd do some of the free or easy things. like check the t-stat, burp/purge, drain and flush again if needed. take your time and confirm that the components work.

millball

The heater hoses heating up first is normal.

The coolant circulates thru the heater circuit any time the heater valve is open, even before the thermostat opens.

Melrose 4r

Was the head planed at the last head gasket replacement?

RAD4Runner

Will certainly dissolve SOME solids if driven for along time.
For your reference:
When we drained our Corolla'c coolant it looked new, fresh, clear and red. However, after the "heavy-duty" flush here's a sample of the liquid we drained out of it:



https://www.yotatech.com/forums/f199...l#post52338321

DMcGarigal

Situation update: spent most of the morning bleeding, burping purging and testing the coolant flow.
With an old rad cap I took the bottom rubber gasket off and slipped a tiny ziptie under the metal disc and tightened it down essentially making it permanently open to flow into the overflow, at first air came out (wahoo!) Eventually no more air came out, but as I would rev the engine the overflow would fill up, and upon releasing the throttle, suck back down that inch of coolant. Not sure what I proved there but it seemed to get the air out at least.

I went for a drive.....

after 15 minutes of moderate driving I stopped to check, no bubbles, normal temp, all good. I drove the same route home, this time a little more heavy footed to put some stress on the system, the needle went up a fraction of an inch but not even above half. To my dismay I pulled into the driveway turned her off, and it was bubbling, not bad, but it was.

the bubbling is coming up through the thermostat and can be felt through the upper rad hose and eventually the air is making its way out of the overflow, not sure if it's worth noting but the heater hoses don't feel like there are bubbles moving through them, only the thermostat side...

DMcGarigal

well, rad is out at the shop, large calcium chunks came out when i flushed it, both ways. we will see.

millball

The aluminum parts of the cooling system hate any alkali, and are very rapidly corroded, while the iron parts couldn't care less.

Always best to use anti-freeze and DISTILLED water mixture, not tap water, as most tap water is alkaline to some degree.

DMcGarigal

Yeah, I've always used distilled and toyota antifreeze, don't know about the previous owner but might have just caught up with me

DMcGarigal

with the rad out, checked on my belts some more and ended up replacing both waterpump belt and power steering belt, good amount of rubber goo from a slipping belt around the power steering pump, both were pretty old looking, some cracking and glazing on both. stay tuned for an update on the rad, probably wont hear from them until after the holiday.

p.s. anyone know of a good supplier of hoses? going to replace all the coolant hoses too while im in there, rad upper/lower and heater hoses... any benefit of going with silicone vs. oem?

DMcGarigal

Oh yeah! Anyone know what this vacuum operated sensor is? The one with two small hoses (in the picture the top one is missing)

DMcGarigal

another oh yeah moment i just had... The thermostat housing, should that have a paper gasket as well as the rubber seal around the actual thermostat itself? its not leaking but i wonder if there's air getting in through there...

RAD4Runner

Bi-metallic Vacuum Switching valve to control EGR. It is not vacuum-operated. IT operates (switches) the vacuum depending on coolant temp.
All those and ther thread they mount on in the block should be cleaned down to bare, shiny metal.


I would try NAPA for hoses.
IIRC 4crawler has write-up on using silicone hoses.

DMcGarigal

what exactly does that do? lol

RAD4Runner

EGR is Exhaust Gas Recirculation. Don't know the details how that works.
Nevertheless, those things need to be cleaned at least once every 25 years
and should look like this:

DMcGarigal

did some research, seems like the EGR lowers combustion chamber temperature, potential cause for bubbling coolant after passing through combustion chamber ports or no?

DMcGarigal

my top nipple on the BMVS is completely missing... so i dont think cleaning it will help haha. looks like those pictured above are all about 100 bucks a pop too

ksti

Mine is pierced.

DMcGarigal

i've got nipples can you milk me greg?