The Mustang PCV Valve is a spring-loaded valve with a specific orifice size designed to restrict the amount of air that's siphoned from the crankcase into the Mustang Intake Manifold. This is necessary because air drawn through the PCV Valve from the crankcase has a leaning effect on the fuel mixture much the same as a vacuum leak. So air flow through the valve must be controlled within certain limits. At idle, air flow is reduced because little blowby is produced. When the engine is cruising and vacuum is high, airflow through the PCV valve is at a maximum to purge the blowby vapors from the crankcase.
It's important to note that Mustang PCV Valves are sized for specific engine applications. The wrong Mustang PCV Valve for an application can flow too much or too little air causing driveability problems. Varnish deposits can clog the valve, so replacement for preventative maintenance is recommended (every 50,000 miles usually). This also goes for the 86-93 Mustang PCV Valve Filter Screen. We carry the best PCV Valves for your Mustang from Ford Motorcraft.
Had a problem with an order/quality issue. I put up a review stating so, and was contacted by Mike Linley, who was soooo nice and sooo professional, I almost felt bad about my review !! I felt the review was necessary because of bad welds/paint. Mike explained that they had a particular issue with that supplier and they had changed suppliers because of it. I must have mistakenly got an old set. (upper/lower Control arms-Foxbody). Mike asked a few questions, and was Sending me an updated replacement set while we were on the phone.!!! This is what I wish all Vendors would do; no arguments, no blame, no B.S. !! This is why LateModel stands out as an upstanding company, and backs up their products with AWESOME Customer service. Very rare in this day and age, and because of this I will be a customer for life, and will spread the good word ! Great to know some honest and Classy companies still operate in the good ol' USA. Thanks LateModel, and Thanks Mike !!! I look forward to seeing the New LCA'S and will review them too...You guys did the right thing and should and I'm overly impressed!