I've had a 2002 f150 5.4 Lariat Fx4 Screw for a little over a year. It currently has 200k miles and overall runs great, but lately it's developed what sounds like a belt squeal when in gear and under moderate to hard acceleration. The squeal will fade away as the truck gets up to speed even at the same RPM. It will also chirp if I rev it in park, but i can't really duplicate the sound while in park.

I've run it without the belt so it is not a belt or accessory issue. Listening on the engine bay it sounds like the chirp (in park) is coming from the front passenger valve cover. I took a stethoscope to it and it seems to be coming from the very front upright end of the valve cover....right at the sprocket.

It's not the exhaust and its not the PCV valve. No shavings in the oil either.
Religious oil changes with 5w-20 and motorcraft filter.

Not sure what this could possibly be. Any ideas or suggestions?

I was considering an engine flush and bumping a little on the oil to a 5w-30.

 

wondering if it isn't a vacuum leak? or maybe you recently had the intake plumbing apart from the air filter back and just didn't get things sealed back up as well ??

If the noise is really isolated to the front timing chain cover area....maybe it signs that your ready for new set of timing chains and tensioners. If that is the what is happening while it open from the tensioners and chains I'd put a new oil pump in too. I wonder if your tensioners are out to the max?

 

Thanks enriched...I tried to catch the sound on a phone so I could upload to youtube, but I can only hear it with my headphones. I'll try to upload it and I'll post it.

I think the timing chain replacement is way overdue, but I have to wait for summer vacation and knee surgery before I can break it down. Oil pump will definitely be on the shopping list.

 

https://www.youtube.com/watch?v=UsbN...ature=youtu.be

If you put on some earphpones, you can here a short chirp at :13 and a then at :16, you can hear it longer. It seems like it squeals at load at 1900 rpm.

 

Yea, sorry, but I can't really hear anything abnormal in the video.

 

yeah, I know. I had to put on my earphones to hear it. Thanks for trying though.

 

Wanted to update.

It's been awhile since posting, but I finally broke down the engine (due the infamous cracked plastic intake under the crossover pipe).

While I waited for the Dorman intake, I decided to further tear down the engine. I had already ordered all the timing components I needed. I used the 12:00 keyhole method and was able to swap out chains without a cam clamp or any problem. The passenger tensioner was fully extended and had almost no "give" in it. I was going to change the cam sprockets, but the sprockets I was sent were the bolt on, and my f150 has the pressed on sprockets.

Cleaned it all up, put it back together, and i can hear a slight sqeal on startup and only once in a while on acceleration. I'm wondering if i have an issue with oil flow.

Any suggestions would be greatly appreciated. I'll check in after i replace the o-rings on my eatc.

 

Are you SURE it's not the belt? Pull it and start it up. If it doesn't squeal, it's the belt or one of the driven pulleys.

 

I had checked before with belt off, but I'll try it again...after all the scrapes and scratches heal up a bit. Maybe that has developed since the last time I checked it.

 

Well, it's been a year since I posted. Trucks still running well. I still have the chirp, but I dropped by my friends shop and he quickly said it was the exhaust manifold. I have not gotten a chance to work on it, but I don't think its that bad to warrant the teardown involved.

Anyone ever have the problem with the exhaust manifold causing chirping?

 

My belt chirps on EVERY shift change that is half throttle or more. even with a new belt and new tensioner.....been down this road for about 5 yrs now.

Actually considered doing SOMETHING about 2 yrs ago..... Just not worth the hassle. Really got pronounced when I built the tranny with some very good help from Mr. Burch (on this forum )

 

To reduce the chirp or eliminate it, use a Gatorback...

 

I got the same problem in park and neutral it only chirps it squeals under load if you gun it hard it quiets down but it's still there usually start around 1200 rpm to 2000 and stops when you get up to speed and no longer excellerating changed the tensioner, idler pully, AC clutch, new timing chains was about to do the harmonic balancer but decided to run it without the belt the squeals still there sounds like it's @ the top right front corner of my engine thinking intake gaskets or manifold but not willing to do all that work and it still be there till I'm 100% sure this is the problem

 

Check your exhaust manifold. I have found a leak, but the previous owner has broken off the studs, so i haven't broken it down to repair yet.

 

Thanks I'll take a look at that. Also. had a notion to check my plug to make sure they hadn't worked loose or something