Manager Forum

I have a loud humming noise comming from the air box. Somtimes it goes away.

Crownvic workin on a crownvic.... how funny is that????

Sounds to me like the PCM might be corrupting the EGR flow and causing backfourced resonance in the air box.... I would get a PCM from a reputable salvage yard and give that a try.

GRAND MARQUIS wrote:Sounds to me like the PCM might be corrupting the EGR flow and causing backfourced resonance in the air box.... I would get a PCM from a reputable salvage yard and give that a try.

I am trying to understand how that might be. I'd a thunk that the way those intake manifold runners are designed and then to resonate back past the throttle blade....... that it wouldn't happen. Is the EGR being commanded at the wrong time, do ya think?

i'm thinking that there was an issue with the air tubes that run down behind the engine. i remember replacing hoses on cruisers before.

The noise is actually coming from the big tube coming from the back of the isc valve.Im thinking the isc is not working correctly.have one on the way,will let uall know how it works out.

"will let uall know how it works out"


that'll be a first.

Rich wrote:"will let uall know how it works out"


that'll be a first.

My thoughts exactly
The PCM idea don't sound that off to me.

Ford had a TSB to address noise issues from the IAC. Not sure it applied to Crwon Vics but have fixed a bunch of rangers and Explorers.

Rich wrote:"will let uall know how it works out"


that'll be a first.

i had a 93 crownvic w motor. I know what noise you are hearing. I had that also. just bout the same time my abs thing went. everytime i hit the brakes going forward, the abs would activate. not oly would i get that vibration in the brake pedal, it would also sound like a huey taking off under the hood. going in reverse no abs issues or huey noise. so i removed the abs main fuse and no problems. also no abs.