Mechanic says it’s not the head gasket.
 

hey i knw this might sound crazy but cars are different like person to person. they act up and are finiky. some like to run hot and others run cool, some like to run with extra coolent and some like to run right on the low line, i don't knw why i just notice this with my cars and others that i help with there cars, i hope u find the real cause but sometimes a car will act up for no reason at all just remember that in the back of ur head

Well is there a big coolant puddle on the ground?
What color is the exhaust?

Do you hear any waterfall noises from behind the dash?
Have you burped the system?

I had the same problem as you for months and yes, it was driving me nuts as well.

Everything suggested that it wasn't the head gasket, exhaust looked fine, no water in the oil and vice verse.

The first thing I did was change the thermostat and this seemed to work for a while but sure enough, not long after my problems were back. Each time it overheated it would dump loads of coolant in the expansion tank and sure enough, the next morning it was back in the radiator.

Eventually I have come to the conclusion that it was a succession of dodgy hoses. Each time I had an overheating problem I would listen carefully under the bonnet, with the engine off of course, and more often than not I could hear a hissing sound.

I have now repaired or replaced at least 4 hoses and changed the clips on countless others and, touch wood, no more problems.

It just takes a small split in a hose or a badly fitted hose to stop the whole system becoming pressurised properly and so it boils and either pops a hose or dumps coolant into the tank.

I also did an oil change and added some oil additive to keep the engine as cool as possible.

by burping the system we mean raising the front end as far as it will go and run the engine for about 20 minutes and then fill the coolant as necessary that should help otherwise you might want to check the connectors onthe thermostat. check the dual vaulve on it too you know the blue one with two ports comming out of it...well thats all i can think of off the top of my head

and yes a bad bent old radiator can cause this also clogs in the places where the coolant goes

my girlfriends na did that for a while it lost coolant in teh system somewhere and then an hour or two later it threw it all up out the overflow tank so burping solved that well hope everything works out for ya

watch the over flow bottle and keep fluid in it

if you have to keep filling it on a regular basis ,,, guess what
you have a bhg and you can continue to drive for thousands of mile this way before you finally have to throw in the towel ...

its safe to drive with a bhg?

An overflowing coolant recovery bottle = a blown head gasket. Its a sign that excessive pressure is entering the cooling system, and can you guess where that excessive pressure is coming from? I don't care who says otherwise. Come down to my shop and I'll pull your head off in 3 hours and show you your mangled, disfigured head gasket.

safe ?

you might pop a hose here and there but you can nurse it along for a long time

You will also erode the coolant passages in the cylinder head from the corrosive exhaust gases entering the cooling system. And the water pump impeller will erode away as well. This is if you drive the car with a BHG for ANY length of time. If it gets really bad and coolant starts to enter the crankcase you will also ruin the rod bearings.

And even worse Hydraulic your motor. Thought I had a bad battery, but Water doesn't compress too well.

you might wana check or search on the frequently asked questions....good luck......you'll be amazed at how much information has allready been asked and answered many times..

She Blew!
 

Well it looks like I was nursing a bad head gasket the whole time. It finally blew two days ago. She started bellowing white smoke and started running a little rough. I parked her in the garage and haven’t started her since. I have a few questions for the HG pros out there who have done this job before. I have never worked on major engine components on this type of car before but I’m up for the challenge. That being said I have found a few sources for gaskets and was hoping some of you could point me down the right path. From what I have read most people go straight to there Toyota dealers but the one I usually deal with here is very pricey on parts. I found a few external web based companies that offer gasket kits made by Felpro and Ishino. I was contemplating the Felpro kit. Has anyone ever used this one before? Any advice on it or should I just buy it from the dealer? I want to make sure all the gaskets fit right and I have heard stories about the Valve cover gaskets on some sets not fitting properly.


http://www.toyotapartscheap.com/

http://www.tpartswarehouse.com/catalog/?N=11790+4294966978+1725+11921+5774

http://www.innerauto.com/store/?D=toyota+supra&Ntt=toyota+supra&Dx=mode+matchallp artial&Ntk=Main&Ntx=mode+matchallpartial&N=4294966 978+4294967259+2471&Nty=1

If your Supra is a turbo you are in for a LONG workout. I'd put the car on a trailer and get it to "IHateHacks;s" garage now. It took me a month to replace the HG on a 1990 turbo, and I'd never do it again. I somehow damaged a nerve in my leg and spent the next YEAR on painkillers.

I used a Felpro and it hasn't leaked again. My BHG was really very mild, no signs of heat and it was only slightly distorted. The head bolts had been retorqued ~50k miles, and it didn't leak until ~70k, so I am a believer that retorquing won't repair any early damage.

I confirmed my BHG by looking down the spark plug hole and finding a little water. Naturally it had to be #6 way in the back. I had the head resurfaced, and it was only out ~7 mils, IIRC. I just cleaned the block very well.

I think a NA engine would be a LOT easier to work on.

At least you know from this experience that mechanics are always right ;)

i guess sacarsam is hard to potray through text :dance:

lol! It can be sometimes.:)