started car w/ radiator cap off, coolant gushing out

[armyguy22]

i have been having overheating problems. hg was replaced about 600-700 miles ago. the oil looks fine. i put a new thermostat in last night and i topped of the radiator. i left the cap off to see if any bubbles would come out of the radiator. well i started the car and the coolant started gushing out like a water hose. today i topped the radiator off again and started the car with the cap on.the car ran for about 5 seconds until i heard a hissing sound and cut it off. coolant was gushing out of the overflow tank.

basically running the car for 5 seconds completely pressurized the coolant system what could cause this?

 

[Angry7M]

Have you checked your water pump?

 

[armyguy22]

no i havent checked that yet i was having temperature spikes before all this happened and i thought it might be the water pump but i didnt think the cooling system could have become that pressurized if the water pump wasnt working

 

[TooGoode]

you most likley have a blow head gasket. the pressure is coming from the motors compression leaking into the water valley's in your block, thus making it a waterfall when you start your car.....how much did you torque your head bolts to and did you machine the head?

 

[armyguy22]

the head was machined and the head bolts were put to stock torque i think

 

[steven89]

head bolts were put to stock torque i think

Theres your problem.

do 75ft/lbs, but if its already blown I think its too late..

But it might not actually be a bhg [im not sure] so maybe get one of those yellow liquid tester kits that checks for combustion gases from the radiator.

 

[zachm611]

yeah if it was the HG i would blame the torque, i dont know if it would blow that quickly though? maybe you should have the radiator tested, i dont know if it would make it gush out but could make it over heat if its clogged or anything.

 

[armyguy22]

my dad wants to take it and get it pressure tested and flushed tomorrow. i was thinking it was clogged too because if part of the system was clogged the coolant wouldn't have anywhere to go. thats the only reason i could think of for the amount of force the water came out with. i bought the car with a bhg and i put in a bottle of head gasket repair. needless to say it didn't do shit. i followed the instructions exactly but i think doing that could have clogged something up

 

[Datsrboi]

Did you resurface the block too?

 

[TurboWarrior]

Its a blown head gasket for sure. You have to do it all over again. Compression from the cylinder(s) is blasting into the cooling system and blowing the coolant out. No point to run it anymore it will overheat probably every time you do.

Next time torque to 72-75ft/lbs. and since its been overheated you should get the head checked again. And possibly get the block checked as well.

Both times ive blown head gaskets it went this way.

Overheating kills the hg in these cars. If it overheats even once you risk the headgasket. So when you rebuild again make sure you burp the cooling system properly and check all the hoses etc. ESPECIALLY at the factory bolt torque.

 

[starscream5000]

As jetjock would say, "this thread slays me". :rofl:

The correct torque spec on stock head bolts has been estimated at 72 ft/lbs, not 75 ft/lbs.

Did you even think to check the thermostat and ensure that it was a properly working unit before you installed it?

Where exactly did you get the t-stat?

 

[jdub]

First, do a re-torque on your head bolts. If they are stock head bolts and are at the stock torque...take them up to 72-75 ft/lbs in two passes using the TRSM torque pattern.

Then, take your thermostat out, put it in a pan of boiling water and see if it opens. You need to use a Toyota or a Stant Superstat...make sure it's rated at the stock 190 deg F temperature.

Do what your Dad says
Get the coolant system pressure tested. That stuff you put in the radiator to fix a BHG could very easily clog up your radiator...especially if it was old. If you need to get a new rad, I suggest you upgrade to one of the thicker aluminum ones...I have the CSF radiator...works well.

 

[armyguy22]

i will follow the advice that you guys have given me but could there be any other reason besides a bhg that would cause this problem

 

[j3pz]

"ya its unicorn jumping around, poking holes everywhere and shitting in the filters"

id listen to these guys, most importantly jdub. he didnt get a light blue name for nothing

 

[flubyux2]

youre boned. you have combustion gasses leaking into the surrounding cooling jackets. a flush and pressure test wont fix anything. if your system is pressurized as soon as you start your engine, its 100% blown. hell, smell the bubbles coming out; they will smell like exhaust. thats confirmation enough.

even factory torque specs will hold a new HG on properly machined surfaces.

im willing to bet that your head wasnt machined right. they probably threw it on the production-level belt sander as opposed to the milling machine or CBN machine. you MUST specifiy that you want it Milled or put on a CBN machine if you want the best of the best.

 

[jdub]

It would have to be a pretty big HG breach to cause this in that short of time...kind like as if the head wasn't torqued down correctly

 

[armyguy22]

my dad took it for a coolant flush today and it was still overheating. its definately a bhg as you can feel the compression from the radiator. i guess i'll be pulling the engine pretty soon. i'm a mechanic so i shouldn't have too much trouble doing it. i have pulled an engine out of an 84 supra but is there anything in particular i should look out for in my 89. im gonna go mhg so how much does milling the block and head usually run for?

 

[flubyux2]

head milling, pressure check and hot tanking is $90 for me around here.

block milling, cleaning was $120.

pull the engine harness out of the fire wall instead of leaving it in the car. much less hassle. dont forget the ground cable on the side of the block. a load leveler works WONDERS. pull the tranny w/ the motor and separate it outside the car, MUCH easier. drop the driveshaft and find a 12pt, half-inch drive socket that will fit in the trans tailshaft, then cover the hole w/ electrical tape; its a make-shift plug so you dont have to drain the gear oil.

 

[isnms]

7M-GTE Engine removal in 49 easy steps - by GrimJack

 

[jetjock]

As jetjock would say, "this thread slays me"

The guy claims to be a mechanic too. That's slaying material right there