Both V6 and V8 ford engines from various years sometimes experience a very loud low pitched moan or howl that sounds as if it is coming from the air intake area..
The culprit is the Idle Air Control Valve. (I.A.C.).
It is possible to remove and clean the IAC with the proper care but it is not advised to do so...Although it may work for a short time, it will eventually fail again and possibly force you to call a towing service when you least expect it..
Price for the IAC varies from $70 to $120 for V8 and $30 to $80 for V6 models. This repair takes me less than ten minutes...
Hopes this helps...I have replaced the IAC for 6 friends and family members who have also had this problem over the years..
My 96 Explorer has has this "howling" issue during hot weather for the past 10 years. I have changed the IAC 7 times and it seems to help. Slight increase in idle speed makes the howl go away. Last weekend it was "howling" again so I popped the hood, listend/felt around for a vibe and determined it was coming from the housing of the air filter. I released the clamp that secures the air filter housing and the howl immediately went away. Reseated the air intake duct back onto the airfilter and closed the clamp and the howl came back instantly. I don't think the IAC is causing my howl, but maybe there is some kind of interaction that isn't readily apparent. Seems to be a vibration around the air intake/filter assembly. Cleaned the Mass Airflow sensor and it made no difference. I bought a new, different brand of air filter and will see if that fixes it. Wondering if the howl is the result of air leaking past the rubber gasket portion of the air filter and causing the vibration/howl. Will post result when confirmed one way or the other.
Intake Howling. Replaced IAC, TPS, MAF, and howling comes and goes. No engine light. Installed clamps on air intake hoses. Car also downshifts at higher speeds causing the engine to rev high and upshifts back to proper gear.
Loud howling noise but doesn't start til the vehicle has been warmed up and is almost instant during the summer. Nothing alleviates the noise and it is extremely annoying. But there has been no decrease in performance due to it.
I had ths howling/vacuum sound coming from me Explorer at high RPM, followed all required suggestions ie replacing ISC and MAS sensors,it did not work. It turned out to be the FAN CLUTCH, replaced it this weekend, problem solved. I dealt with issue for about 3 months until I finally figured it out. Good lock
dobynika, Schenectady, NY, April 20, 2014 05:31
hello from surrey b.c Canada. I have a 2003 explorer 119k that has been idling rough and making a howling sound about every 30 sec to a min.or when idles down. sound comes from the air filter intake.I read some reviews and took the advice of one owner. I removed the Iac valve at the throttle body and cleaned it with ford tune up spray. the inside was black with carbon. then removed the intake tube from the throttle body and opened the buttetfly manually and cleaned the inside of it . it wasy very black and full of carbon too. (soak the iac or use a tooth brush to scrub the inside) the truck runs 100% now.
Very easy to do on 4.6 I had this problem for about a year and slowly got worse . even took to a mechanic and charged me 100$ but did not know the problem. remember when we were young and we had carburators we would use carbout or something like that .. this is the same thing just carb build up in your engines throttle body unit