I have a 2000 f-150 with 5.4..140,000 miles.. Can you have an exsaust leak only when cold or when cools down? I have a strange sound coming from the passenger side rear of engine when i first start up,(fluttering???) it goes away after a few minets(not piston slap) it really sounds like exsaust leak, and then also does it a little after sitting for 15-30 min or so but does not last as long or is not as loud. I replaced the belt and tensioner to rule out belt slip. (I guess could still be a bad pully on an accessory or somethig?) I covered the tail pipe with hand and only get alittle hiss from the muffler area(prob drain hole). Hmmm could it be a plug worked its way loose??? just thought of that. The guy who did my plugs 30,000 miles ago is a master ford tech and we discussed the proceedure to be sure plugs in correctly. Can anyone give me some more info on what this MIGHT be??? BTW truck runs and idles fantastic!!!! Thanks

 

I would definitely check the plugs. Several have heard a similar sound before they blew a plug out.

 

Thanks, after i thought of that i called my buddy, he has just opened his own shop after working for ford for 15 years at the dealership, so i will take it to him today to see whats up...whay ticks me off is it really has to be cold to do it.I just want him to check the plugs for a loose one.

 

A plug would get quieter as everything heats and expands, so would an exhuast leak, which is basically what a loose plug is. It is the exhaust escaping out the plug hole.

 

yea, im afraid thats what it prob is!! hope no real damage is done. been driving it for about 500 miles with noise, but have taken it easy on it not knowing what it was. It also does something really strange and thats the real reason i changed the belt tensioner and belt...it will squeel when you get on it at 30mph at the exsact second it make the 1-2 shift(sounds just like a belt squeel) you know....how you are cruising along at 30mph and floor it and it down shifts into 1st and winds out to 2nd, well at the up shift to second it makes the squeel!!! and it is reproduceable. what the heck can that be....better not be tranny!!!!!! I get that service reguarly!! thanks for all your comments.

 

If it is a loose plug, the damage occurs when it backs out enough to blow out, taking threads with it. Just leaking will not hurt anything. If it is loose, get it tightened immeddiately.

 

Thanks bro

 

The rearward exhaust manifold studs are known to break too. I noticed mine were after it got cold... could hear it in the exhaust. The squealing wouldn't be a part of that though...

 

The squeal really sounds like the drive belt slipping. Mine has done it occasionaly with a hrd shift at wide open throttle since I got a tuner. If it is not the belt slipping, I would guess it might be an altenator bearing.

 

wow u guys are great......The torque is fantastic on my truck still and when I drive it like that it shifts great and pulls hard into 2nd...gotta be a strain on all those old parts in there!! I guess she just gettin old like me but im keepin her as a daily driver. My 2008 f-250 is on order with that 6.4 desiel in it...im hopin its a good motor...yes ive done all the internet reading on the engine. thanks again ill let u all know what we find.

 

exsaust manifold leak!!! studs will prob break off when try to remove or tighten. buddy told me they rust out and get play in them...but u all prob know that allready.as soon as i get my new truck i will leave it with him and have him do whatever it takes to fix. hope not have to easy out the studs.

 

My 98 makes a ticking sound that goes faster with higher RPM's. It goes away when the truck warms up. I took it to my mechanic yesterday and he said he thought it was a leaking exhaust manifold. A few months ago when it was at the dealer, they said that the bolt on the passenger side manifold was broken off so this confirms this. The dealer wanted $1000 to fix this so I said I'll live with it.

 

It only does it when start up when cold and a little bit on a hard 1st to 2nd upshift when nailing it(he told me this due to eng movement and changing exsaust pressures. Since he is a friend im hoping he will not charge me to much, but i trust him and he has to make a living so i will pay him what he asks to fix it. I guess we will not know how much till we find out how many are loose and how many break off.

 

This sounds very similar to the problem that I am having. Mine was making this sound before I changed the plugs and is still making the noise, in pretty much the same manner as QUICK83. The exhaust leak sounds like that could be the target. Thanks to all for the info.

 

In reference to the WOT 1-2 shift. Yes, it is the belt. Mine used to do this, changed the belt twice no difference. Spent the extra dollars on a Gatorback, and the sound is gone. Spend the extra few dollars on the gatorback. Happy shifting, quietly....