87 hatch

somebody told me my up and down idle could be from a blown head gasket . does this sound right ?

fats429

Yea it could be , or it could be 20 other reasons , is the car flashing a cheek engin light , that could be promsing , the olny way to know the head is blown for shure is a leak down compression test , dont drop that kind of coin a guess or from what some one told you , what els is the car doing , aney smoke , back fire , water in the oil , lose of pick up ,

luckythirteen13

if you have a blown head gasket more then likely you will be burning coolant. does any white smoke come out the exhaust? or are you low on coolant? i was told you can take the radiator cap off, run the engine and if bubble come out you have a blown head gaasket.

you could also have a vacuum leak, a bad maf sensor, tb sensor could be off, miss firing, bad o2.......lots of things

Tims 88GT

the best way to check if you have a blown head gasket is take the oil cap off the valve cover and if it is a light gray or white you have a blown head gasket if it is black you are ok. the idle thing could be a whole lot of diff things

87 hatch

i just worked on fixing a couple of known vacuum leaks and found a who lot more. One was a tube that is bigger than all the other small vacuum lines and it has two red marks on it. It connects to the middle of the underside of the upper intake plenum and then to something on the firewall. This vacuum line was so chewed up that i barely touched it and it came off. My only problem is to somehow get the clamp and broken end of the hose out of there and the new hose back on. It looks like im going to have to take off the entire upper intake plenum. So as soon as i start it again im sure it will run fine. Thanks for the help...

88GT40

pretty sure if it was a head gasket you would loose a lot of power and it would be noticeable, spray carb cleaner on upeer to lower intake seems and on all vacuum hose ends and listen for idle fluctuation from the spray this would indicate vacuum leak, try cleaning your throttle body and iac motor, and a compression test wouldn't hurt any either. keep us posted and we'll feed you more ideas if necessary

87 hatch

i still have a lot of power , and i will try the carb cleaner trick. Im pretty sure its just vacuum. Those vacuum lines suck!