Vacuum problem
Asked by JACKSONS0822 Jan 07, 2016 at 08:53 PM about the 2003 Hyundai Tiburon FWD
Question type: Maintenance & Repair
Man guys I bought this Tiburon 2003 2.0 it
has really strong vacuum when I pull the oil
dip stick out when the car is idling when it is
in you can here a vacuum leak around the
plug wires where they go into the head I am
lost any help would be great I replaced the
pcv valve
13 Answers
A vacuum when you pull the dipstick is normal and expected when engine is running. The greatest vacuum is at idle, the PCV is sucking air out of crankcase. Now a a vacuum leak around spark plug wires is beyond me.
JACKSONS0822 answered 8 years ago
It goes away after I pull the dip stick so I have no clue thanks for your imput man
If you hear vacuum when the seal is broken around the plug wires where they go into the valve cover you probably need a new valve cover gasket and spark plug well seals.
JACKSONS0822 answered 8 years ago
I will go tomorrow and get the gasket then so you don't think it's anything major then?
The spark plugs are set deep in the valve cover on a hemispherical head meaning that the valve cover has a seal around the spark plug well. The seal that keep oil out of it is allowing air to get by and giving the suck sound. When you remove the dipstick you are giving the vacuum another easier path to flow thus the sound going away. The only thing I wonder about is how much vacuum its actually pulling and if there is a vent that is stopped up causing to much vacuum to be pulled on the crankcase. Ive seen crankcase breathers clog and cause the rear main seal to give off a sound like an oboe reed.
The pcv system pulls vapors and any pressure out of the crankcase but it isn't supposed to suck it down til any of the gaskets or seals fail.
JACKSONS0822 answered 8 years ago
Where are the crank case breathers located at?
JACKSONS0822 answered 8 years ago
I have checked and every vacuum hose pull good vacuum but the one coming from the breather tube has a box with a plug in on it on the other side is a hose coming off of it and just stops looks like it used to go somewhere but don't know where
The small tube that comes off of the inside radius of the intake elbow should lead to the crankcase breather.
none of the info that i have tells me exactly where the breather is but it should be somewhere on the valve cover. pcv system short answer. fresh filtered air from air cleaner to crankcase where it isn't submerged in oil (Usually the valve cover) back out of the crank case with a one way valve (pcv) to the engine side of the throttle body for the most vacuum available.