Is there an easy way to check for vacuum leaks in a late model car?
February 8, 2012 by Admin
Filed under Discussions
In the past 10.000 miles, my gas mileage has gone down by about percent 10th I had to have the mass air sensor replaced, and at that time they found a vacuum hose that leaked, and fixed it. What else is there to check when the engine is computer controlled?
If you want to check for vacuum leaks, start your car and spray automotive starting fluid(ether) around the top of the engine and around the vacuum hoses and connections. If the sound of the motor changes, you have a leak.
DO NOT USE STARTING FLUID!!!!! Use carberator cleaner or wd40.Starting fluid is to stout if enough gets in it could cause damage.
You can attach a vacuum meter any of the manifold vacuum lines. It should operate smoothly as manfold pressures change. If you see the needle jumping all over the place that indicate a vacuum leak… if you can’t get good stable pressure at low RPM that may indicate vacuum leake as well. There are alot of things in a car that operate off vacuum… including power assist for your brakes (making your brake pressure harder to stop), the timing advance on your distributor (causing loss of power at high RPM), etc.
I have seen people use a carb cleaner or something of that nature sprayed around the engine componants that you feel there might be a leak. The engines idle will change if you get near a leak. I would say you would want the engine to be cold at the time.
Get a can of WD-40 and spray it all over the running engine (except the exhaust manifold).
If the idle speed goes up, you just hit a vacuum leak.
Don’t worry, WD-40 won’t hurt anything, in moderation.