superhatchbackbros

i let my 90 civic hb si run for about 20 mins in my driveway and then all of a sudden ther was a hissing sound and it was starting to SMOKE! i opened the hood and the reserve tank -overflow- was full and it was BOILING so i looked at my temp gauge and the needle was lil over half so i shut the car down and let it cool. ........... does anyone know why it would do that, overflow and boil and what i can do to fix it and provent it from happening again

wpgcivic

sorry to tell you but your headgasket is done...

Rostr02

thats what i would say too

superhatchbackbros

i havnt started my car in like 2 weeks and this is the only time it happened i ran the car so far only like 5 times sittin in my driveway its gotta be the thermostat is stuck open the engine has been runnning fine otherwise its been smooth- just a lil water comin out my muffler . bc it was sittin i think and i just put on new intake wires- plugs thicker grounds battery this is the first time the over flow has ever filled up and was boiling like it was so im guessing it was the thermostat im gonna replace it asap and put fresh antifreez in when i shut the car off and it cooled the over flow was empty again i havnt started it since im gonna replace the thermostat then try it again like i said i asked a few people with crxs few said there car had same thing happen this week so i dont think it would be a head gasket

dr_latino999

If it were boiling or had the appearance of boiling you have two options -

1) Air was being introduced into the coolant system from an undisclosed point at a high rate
2) Super heated gases have been introduced into the coolant passages through a faulty headgasket.

Have a nice night

shocker

Freind had that problem to,it was a mix between a bad headgasket and a faulty radiator cap that didn't keep pressure so there was lots of overflow in the resivoir,and of coarse it was boiling because his car was running,and your car overheated because of lack of pressure in the cooling system prolly...

HatchBox

why just to the conclusion that its a bad head gasket?

the radiator cap controls the flow to the overflow tank.

Replace radiator cap first. Go from there.

wpgcivic

he also said that the car overheats, check to see if your heater is blowing hot air, if not then your headgasket is supremly shot, sometimes your headgasket can still be shot and you will get heat

superhatchbackbros

thanks for the help everyone i only had my car for a month havnt even drivin it yet i been just workin on gettin all new parts for the car everything and anything so i only had the car started and running sittin in my driveway for like last 5 times running it a lil each time during the like 3 weeks while i put new parts on it this is the first time something like this ever happened to me on any of my cars and when i got in the car my fan was on second notch over i didnt know that at the time it was blowing out cold are i dont think the heater was on but im might of been i just clicked it off when i felt the air was being blown out of the vent and i shut the car off the needle was only a lil notch over half so it wasnt that bad bc it was scary bc the overflow was hissing bc it was boiling lol and it was steaming that was the only thing that was hot or doing anything on the car at the time