2012 Epxy - Start Up

[UrbanCowboy]

Hey, everyone. Thanks for all the great advice lately. I bought a 2012 Epxy XLT with 176K miles on it about a month ago. Great truck, love it so far, got it for a great price and I'm fixing it up properly.

I have a question about when I fire it up when it's a cold start. When I start it from a cold start, it fires up great but is really loud for the first 30 to 45 seconds or so. Definitely hearing the exhaust manifold resonate, however it'll quiet down after about 45 seconds. Sometimes, I'll tap the accelerator and it'll quiet down right away (I don't do this all the time I'm just trying to figure out why its so loud).

I can't smell exhaust in the engine compartment and when I touch the coil packs, they feel solid. I first thought that maybe a spark plug was loose and causing the noise. The previous owner has replaced the plugs and coil pack fairly recently.

My phasers and roller followers seem to be operating just fine and it doesn't sound like valves "ticking", and I can't detect a crack in the exhaust manifold. It defiantly sounds like an exhaust noise, not a valve tick or something along those lines.

I used to have a 1999 Ford E350 van with the 5.4L, but I don't recall hearing it so loud when I started it up, but a van has the engine buried and is insulated for noise because it's basically in between the driver and passenger seats. On that vehicle, I had a plug blow right out of the cylinder, it didn't need a helicoil, but it was when the threading on the plugs was shorter than they are today causing this issue. I'm glad Ford changed the plug design.

So I'm somewhat familiar with the 5.4. I'm not too concerned about this, and it may just be that the noises are "new to me" and I'm not used to it yet.

Any thoughts on this or is this something others experience and is normal?

Thanks again.

Note: I have had a couple different mechanics look at the vehicle already. I had my suspension replaced and had it inspected by my local shop when I bought it. Neither said anything about the start up volume. So maybe I am not used to it, but I just want to be sure.

 

[S20Workstation4]

Even though the exhaust manifold may not be cracked, it can be a broken manifold stud. Broken studs are more common on the 5.4 than cracked manifolds.

Don't know if it's possible, but try and upload a video of a cold start to this post here. That'll give me and other members a better understanding of the noise.

-Joe

 

[UrbanCowboy]

Good idea. I will check the bolts on the manifold. My wife's vehicle had something similar happen. If that doesn't take care of it, I'll record a video and upload it. Thank you!

 

[Swede252]

I recently replaced my engine, having it rebuilt very good local shop. And reassembling everything we had some rust on the mating surface and thought it would be fine to quickly flat file. That is not actually a good flat surface. So we developed a small leak during start up. As the temperature in the head and the exhaust manifold increased the leak closed. It would never go away because the meeting services were not true, not enough for a gasket to hold a seal. The studs in the head can break and the nut can appear to still be in place. So buy some PB blaster, soak everything before you attempt to loosen any of the nuts. You will need an arsenal of different Wrenches, and sockets and adapters to get at each and every bolt differently, the starter will be in the way so watch some videos on the secret to getting the starter out of your way. It is not fun. We ended up buying two new doorman exhaust manifolds. The passenger side is installed with the starter wrestling complete. The driver side has been fine since the engine install, but I have the new manifold and the gaskets and studs and nuts in the box ready to go.

 

[max78]

Generally if you tap the throttle and it instantly gets quieter its not an exhaust leak, it generally takes time for things to swell and seal. Its really hard to tell what could be happening without hearing it, a video would help.

Only thing I can think of if its not an exhaust leak is the cold start strategy (like the 5.0 does). It can sometimes adjust cam and intake runner stuff as well as increase the rpm for better cold starting and that can cause it to be louder during initial start.