Hi,

I just bought an '89 Supra a couple months ago. The previous owner claimed to have flushed the cooling system. It runs completely fine around town and on the freeway UNTIL I reach stop and go traffic on the freeway. It then begins to overheat, and I have to blast the heater until I can get off (and in 90 degree California weather this is not pleasant!).

When I stop and open the hood after this, the coolant reservoir is jiggling like crazy and spews out coolant from a horizontal black tube that's on the top of it.

I am constantly checking to make sure the radiator and coolant reservoir are full, and I don't know what's causing this problem.

If anyone could suggest any and all possible causes, I would greatly appreciate it.

Thanks,

James

you are not going to like it
let me introduce you to the term "BHG"

it sure sounds like you have a blown head gasket "bhg"
welcome to the bhg club

rushing water sound in the dash when you first start up in morning ?

unfortunately ^ agreed

go to a mechanic you trust and get a block check done... this will tell you if you have exhaust gasses in your water... a compression check will also give you some tell tale signs...

or.. you could be really really lucky.. and have a blocked radiator or air in the system

well this might make you happy, you might want to try something as simple as changing your radiator cap. I had it this morning while delivering my newspapers same thing stop and go, and it started to overheat, i would quickly turn on the heater before it got to hot. So i figured the car runs same as always, its this humid weather that has changed, so maybe the cap is bad, and its not pressurizing the system to the point of get full cooling capability. So changed the cap, rode her up and down hills for awhile, then started to stop and go, stop and go through the neighborhoods by me, and then i just let her sit idling, cause once she started to heat up even after i turned the heat on, and she cooled down, once i turned the heater off and let it idle it would start to raise up, everything is great so far.

Yep, rushing water indeed in the morning, although I haven't had a clue where or why.

thanks guys for all the advice. I'll try the radiator cap first, then see if replaceing the whole thing helps.

What about the water pump? It's been suggested to me, so i'm just wondering if that's a potential cause too.

i wouldn't use after market stuff . costs a few extra bucks but atleast then you'll know if you used a toyota cap

is this a turbo or N/A ?
i've driven with a bhg for thousands of miles . just kept checking everything every morning an avoided heavy traffic .
even toyota told me i didn't have bhg at one point , i think they only really check compression and if that looks ok they write off the bhg idea. generally it's not like water comes gushing out
see here how thin the distance is from cylinder to water
http://www.ddmcse.com/turbo/images/bhg.JPG
you'll see the blown area this gasket had a special bite in the gasket to prevent gasket movement and it really did bite down and leave a pattern on the head and block

you also might want to look into your fan clutch too, if the clutch is not working when it is suppose to then this would also cause your car to over heat in stop and go traffic, my car is still overheating stop and go, i'm gonna change the clutch fan.

one reason i switched to electric fan . reason 2 : more hp cuz: the electric fan isn't driven by belts and the motor

N/A

How does it work? How does the bhg cause the overheating problem, and the water rushing? I never would have thought of it. Also, how much am I looking at to fix it?


I don't think it is the clutch fan since i'm having no problems with the clutch

once a leak starts hot exhaust starts heating up the coolant because it's passing the gasket and coming in contact with the coolant ..at the same time the coolant is burning off as it seeps into the cylinder once you take it apart you'll see signs of white on the exhaust .
the rushing water sound comes from the lack of coolant in the system cuz some it burned away

since you are'nt boosting this engine a stock gasket should be fine for you .


there are a few things you can do to prolong your agony but having been through it before i'd say "get her done"

check the block and head for signs of corrosion

http://www.ddmcse.com/turbo/images/process/0hrs.JPG

notice the corrosion here .. a stock gasket is somewhat forgiving and will form to the pits much more than a metal gasket . the metal just won't fill those pits and gaps . since i wanted more boost and knew i was going to put pressure on the system i went with metal and smooth the block to a nice fine finish
you will be pleased to find out the job is not as tough as you may imagine .. just alot bolts not much in the way of special tools

directions for BHG

http://www.geocities.com/MotorCity/Speedwa...y/1636/bhg.html

clutch fan is totally seperate from your clutch for your transmission. the clutch fan when it operates properly locks in place and brings the fan to the appropriate operating speed at which if its not working in stop and go traffic would cause you to overheat.

since you aren't boosting you might be able to get away with a new gasket and torquing the head bolts down to better than factory specs of 55 lb i've done 72 lbs and i think i did 80lbs this last head . but see how bad the block looks .. you really should check the head for flatness .

you want to go all out of just get the damn thing done ? you could do it for real cheap
how many miles on the engine ?
ever changed the timing belt ? if u r going to do the head now would be the time to change the Timing belt

i'm still saying he needs to either look for appropriate signs og bhg or have a shop look at it, cause my car is doing the same thing in stop and go situation, and i know i don't have a bhg, been checking coolant for past 3 days, has not moved an inch, no mixing of coolant and oil, no loss of power, no white smoke once she has warmed up. gonna have smoke at first start due to condensation build up in exhaust.

king is your fan working ?

i don't know where the oxygen sensor is on the N/A but i know it's right behind the turbo on a gte and it's easy to pull . one could easy see the condition of the exhaust

Go to a recommended repair shop and get a chemical test done to see if the gasket is blown. It is very cheap test. Watch them do it. I too drove mine for three months with bad gasket. It was putting gasses into the cooling system when the fuel was burning, (most pressure in the combustion chamber). It pressurized the system, and would push it into overflow bottle on LONG drives. I wasn't loosing coolant into the engine. I did get the heater core gurgles alot.

Head gasket solved all problems.

If your 7mg is over heating the firt thing I would do is go over your cooling system, Replace the thermostat anf flush the coolant and replace it. If the problem is still there compression the motor u might have a blown head gasket :(