I notice that one of the reponses to update of my engine light, stated possible : leaking intake manifold, or replace PVC value, well on 10/22/08 after hearing a noise coming from my truck, i had the dealership look at the truck, and was told it was my Intake Manifold, well I had 5 gaskets-intake manifold replaced and removed intake, and replace PVC value and tube, should I be having this problem if that is what it is now? The cost was 426.24. Thank You.
The Answer on 2005 Ford Escape
by poorwomen in Virginia Beach, VA on October 10, 2009
ANSWER by patrick mannion , October 11, 2009
Codes set indicating lean running conditions, lean misfire or vacuum leak problems are best identified by using a "smoke machine". Many automotive repair shops have a machine that generates an inert non flammable low pressure smoke that looks similar to cigar smoke. The intake manifold is sealed off, and smoke is put into the engines intake manifold. The smoke then fills the engines crankcase and if there are any vacuum leaks from gaskets, hoses, or housing smoke emits from the source of the leak. Some mechanics will use propane or aerosol carburetor cleaner, with the engine running they will spray the cleaner or propane around the intake manifold and vacuum hoses. A leak will cause a "lean mixture" condition, when the flammable fuel (carburetor cleaner or propane) comes in contact with the source of the vacuum leak the engine idle speed will raise as the engine has received "fuel". this method of finding a vacuum leak works but is not recommended as it can easily cause a fire.