Hey all...I have a LOUD tick/diesel type noise (not Powerstroke loud though) from idle to around 2K rpm when ice cold. It goes away when warmed up, even slightly. Last weekend while descending down an enormous hill, I was in 2nd gear, foot on the brake, spun up to 2K+rpm and could hear it again...this was fully warmed up and off the gas. To add to the issue, our fuel economy (what?) has dropped from a usual 15.5 combined to 11.3.

I'm suspect that it may be an exhaust leak somewhere, sucking fresh air in to the exhaust, throwing off the O2s (reading lean) and thus forcing the computer to add fuel. I don't think that suspicion is too far fetched given the noise goes away with temperature.

I have narrowed the noise down to the passenger side of the engine. It is loud in the wheel well and resonant (like around the Y-pipe, and exhaust manifold), but also the ticking is present up top around the intake manifold and Throttle Body, only quieter.

My question before I start ripping and tearing. Has anyone here experienced a Y-pipe or exhaust manifold leak? How about intake manifolds? Lastly...do these rigs have an air injection system? I didn't see anything that would lead me to believe it would, but maybe I missed something! Thanks all...

Sam

1999 Expy 5.4L 4x4

 

Take a look at the studs holding the exhaust manifolds on. If any of them (8 total) are snapped off, then you're a victim of a very common problem with these trucks.

 

Victim! I like the sound of that! HEHE.

Hey...so what's the scoopage? Does this sound like a familiar noise/description of what you might be suggesting?

thanks for the quick reply!

Sam

 

oh yes, I have now searched and seen the horror that has been the passenger side exhaust manifold on the 5.4. OUCH! Headers here we come, if in fact that is what I find.

 

Here's a post of mine regarding the installation of shorty headers in my Expedition.
https://www.ford-trucks.com/forums/7...f-cover-2.html

 

Yeah, ok, confirmed...I have one that is loose and will not tighten...so stripped or whatever. That is the front lower passenger side. Then I have the upper rear passenger side nut missing, with a piece of stud sticking out. GREATEFFINFANTASTIC!

Another thing...I don't know why it sounds so different outside the rig...lukewarm it makes the noise only coming off throttle. It is more of a Jetson-Mobile (if anyone here can recall that one!) type noise. I fully intend on going out with the laptop and a microphone and recording the noise for you all. And yes, while it is loud up high in the engine bay, it is much worse down by the exhaust manifold.

Thanks guys...this is no longer a nickle and dime mobile.

 

OK, got a great audio clip, about a minute in length total...great sounding Ford I got here...problem is, I think I pissed off the bandwidth police with my host, so can't access to upload to my ftp site. WEIRD!

Anyway, as soon as I figure it out, I'll post up. It is about a 2.5 meg file.

Sam

 

alrighty then...click here for audio!

 

awesome man! Could you discribe the EGR and dipstick modifications necessary a bit better though? Anything I can't find at the local Kragen? Those are some seriously inexpensive replacement parts! Current price $134.95!

 

There isn't really any modifications to explain. I just replaced them with the OEM parts from the dealer. They go back in just like the stock manifolds were installed. You'll need the ERG tube, the EGR adapter at the manifold end of the tube, and the engine oil dipstick tube (not the dipstick itself). You have to remove the dipstick tube to get the driver's side header on because of the plate on the header that bolts to the block. There is no slot in it for the dipstick tube to pass through. Since it's pressed in (or hammered in if you will), you will destroy it when removing it. You tap the new one in after the header is installed.