vintageman

So 2 days ago i noticed that when accelerating with the rpm between 1500 to maybe 2000 my engine is a little louder like i have an aftermarket exhaust. If i let off the gas and then back on it, it goes right away. No codes at all, no change in performance, just does it sometimes upon accelerating. Any ideas? It is raining here so i haven't had the chance to look yet. Thanks for any help in advance. 2004 f150 fx4 4wd. Btw, just did timing components, phasers, and lash adjusters with followers about 3 weeks ago.
Tom

lewissa81

The seal around the front of the air filter tray disintegrates, and can cause a moaning type sound. A lot of people replace it with weather stripping from home depot. Basically it's just engine noise that bypasses the baffle in the intake tube.

vintageman

Thanks for the response, I will definitely check that in the morning. Hopefully that is it, it just seems kind of strange that it only occurs around 1500 rpms and is not affecting performance or throwing codes. Intermittent problems suck. Thanks
Tom

vintageman

Well, I opened the hood and found that the air filter resonator thing that goes to the fender well, had popped loose from where the air cleaner goes, put it back together and tightened the bolt better. Probably where my intermittent noise came from. Also, the foam from around the air filter drawer is almost completely gone. Gonna test drive and go to home depot and pick up some weather stripping. I really appreciate the help, hopefully this is the fix when I get it installed.
Tom

lewissa81

Did you get it fixed?

vintageman

Yes, so far so good. Also found that the old weather stripping was almost completely gone, put in new and she sounds great. Kinda feels like more pep when accelerating as well. Thanks for ur advice an help on this.
Tom