how do i know if i have a vacuum leak?

[Dennis]

there is a hissing sound coming from my engine, the tranny misses, it takes about 5 minutes to get it to 80mph, i get horrible gas mileage, etc. are these signs of vacuum leaks? :ugh: thanks :dunno:

[A20A1]

are you sure it's not a coolant leak, check your fluid levels... also are you automatic?

but yeah it might be a vacuum leak.

[Dennis]

yeah it's automatic.

[Dennis]

but what does a coolant leak cause? because i know that one of my coolant tanks is empty but i think it's the reserve tank, and my car does seem to get kinda warm under the hood but the temp guage has never went up past half way.

[k-roy]

The easy way is to get a can of carb cleaner. With the car running spray a small squirt directly into the carb, you will notice it raises the rpms for a couple of seconds. Next spray cleaner on the vacuum lines and around the connections slowly. If you idle raises again that means that there is a leak and the carb cleaner is being sucked through the hole or crack. If you do not have emissions testing I highly reccomend removing most of the vacuum lines, there is a thread concerning it posted in the HOWTO section of this board. Good luck.

[shepherd79]

ok, the hissing sound is your vacuum leak. it is kind of hard to find with all those lines, but if you listen closely you should be able to pin point the location.
the coolant problem, it is eather you have hair pin hole in the hose, which means when the car is cool the hole is shut, but when the car gets hot, coolant starts to expand and the hole opens up and starts to spray everywhere. i had this kind of problem a few times, nothing serious. the other thing that can cause leak is blown o-ring on carb base gasket. the coolant may be leaking down to intake manifold slowly. if that is what it is you should see some white smoke out of your exhaust when you car is fully warmed up.
check your coolant level, make sure you keep it up or your car will run like crap. our cars don't like low level coolant.

[A20A1]

I'm just trying to associate the tranny missing with the hissing... :D