FLMustangMan

I put a new IAC on my 96 mustang back in September and havent had a chance to drive it much. I've only put 300+ miles on it since. So I've started driving it again and after about 5 mins of idleing it starts to make a humming from the intake filter. Then it slowly gets louder. I can hear it across a parking lot. I've researched and basically found that this is due to the IAC valve having a issue and causing the air to create a frequency that echoes back through the intake. My question is did i get a factory faulty IAC or can it be something else. Should I attempt to clean it even though the book says they can't be cleaned. I checked the gasket on the outside and it looks like it is good and set right. It was ordered through Summit and is a Motorcraft part. Return through warranty? Thoughts ??????

Next, after a week of driving I plugged my SCT tuner in and saw the P1100 code. I understand this is a MAF sensor or voltage issue but I have also read in the DTC codes that it can be caused by a dramatic fluctuation in air movement. Could this code be thrown by the IAC issue since it is obviously changing the air movement to make the humming/horn type noise???


I will also check tomorrow to see if Mabe I oiled the air filter to much and the sensor just needs cleaned.

brys00gt

Do you still have the silencer installed before the IAC?

FLMustangMan

What do u mean silencer? Are u talking about the stock intake housing? My car is supercharged so it goes filter to procharger to intercooler to blow-thru MAF to throttle body. I've never seen any type of silencer device in the plenum. So I don't think I have one. And it has always been fine until the update of a new IAC valve. That and the new coil packs and plug wires are the only that has changed recently. And I changed those in September, drove the car a couple times, and it has sat till the last week. Didn't hear the humming before.

FLMustangMan

After posting I realized what u meant. Duh me. Lol. The little black box on the air hose that comes out the front of the IAC valve. Yes I still have it. I only removed the hose end off the IAC unbolted it and installed the new IAC. Then pushed the hose back on the end of the IAC and clamped it down.

FLMustangMan

Do the silenced ever get bad??? I've never heard of this before but when I get home from work I will look to see if it is dirty, clogged, etc. Mabe this is why it take 5-10 minutes before the sound starts???

FLMustangMan

UPDATE: FIXED

First - The IAC was bad. Apperantly it was an actual factory defect. The first time I've ever had a factory defective part. And even though Summit only has a 90 day warranty on the IAC they replaced it anyway. I even got a three dollar check back from summit since the IAC has gone down in price since. Thats awsome. Thank you Summit Racing.

Second - it wasn't a Motorcraft (Summit doesn't sell Motorcaraft IAC), it was a Standard Motors IAC. And they sent it straight from the Factory instead of going to Summit and then to me.

Third - The P1100 was caused by the MAF sensor being coated in the air filter oil. I guess I over sprayed the filter this time. Never did that before. oops. Easy fix - Electrical cleaner and a soft rag.

Hope this helps any with this problem.