Well not really a cat, but close to the sound a cat makes when they are about to fight, you know that evil sounding growl? I am hearing something behind the stereo glove box area, and it is most noticeable when parked because of lack of road noise to interfere with it. When I rev it up a bit, it takes a second to hear an increase in the speed of the noise, and same lag on the downside of RPM's. When you shut the engine off, it continues on for a second or two, then stops. Does it in any gear(Auto) , and doesn't matter about the A/C or heating selector position. I am thinking it is vibration from a bearing in an air pump, A/C compressor or power steering,transfering through it's lines. I can only think of one thing short of getting a stethascope to listen to each one. That would be to pull off the belt and see if it is infact an engine accessory. This problem is on a '98 F-150 5.4 Supercab 4x4.While I have your knowledgeful brain here, can you tell me if I have the notorious bad sparkplug heads, I am sure they are,and can anyone tell me if those power doorlock are programable to do different auto functions. They work on my remote , and lock automaticly, but wish they would unlock too!I will put the rest of my questions in thier proper places. Thanks for you time

 

from what i understand the spark plug problem is rare.alot of it was to due improper torquing of plugs. i have 2 4.6s f150 and a crown vic. no problems at all

 

Yes , I am not scared about the plugs comming out, but rather them not comming out. I had a Toyota that was always getting it's plugs loosened by someone in the night, just kept an eye on them. I was more wondering if they were the long platinum ones?

 

i heard the v 10 had it the worst for spitting plugs out.

 

Well, I have read almost all threads on the plugs, so I am not scared. More that I was curious to see if I had the long ones, as I don't have a owners manual, or a shop manual yet.I am sorry if I have dredged up the plug issue again.

 

Leave your truck running and open up the hood, I had a similar sound but could hear it most notably outside the truck, I found that on the passenger side valve cover, there is a PCV valve, the spring in the valve was bad and the valve was making a horrible noise, $6 and 15min later (including trip to store) and it was replaced, nice and quiet! Don't know if yours is the same problem, but I thought I'd throw it out there.

Josh

 

might be your power steering pump. my 96 crown vic makes that same noise. especially when its colder out. its not like a bearing noise.cant reall explain it. i guess they are notorious for that.pump works fine, steerings fine

 

Nailed it right off the bat Josh. Never had a pcv valve make a sound like that, but sure enough, thats was what it was. I feel sorry for someone who would take it to a bad shop and tell them they thought it was a steering pump or such. They might get a steering pump for no reason, " .. and you needed a new PCV valve, no charge on labour for the valve though Sir." I must admit I was not a believer about that recomendation, but you have my ear now,
THANKS!

 

LOL, I just speak up when I have an idea, sometimes it pays off, sometimes its not what I thought, its especially hard to diagnose "sounds" over the internet. Truthfully, I posted about this problem about 3 weeks ago and nobody really seemed to know what I was talking about! So I just replaced it on a whim. I read a lot on the forums and try to remember what I can to help those that I can, as well as myself!

Glad it worked out.

Josh