I have seen this discussion on a few different sites and have tried a few of the tips. However, with no success I'm hoping someone here may have an answer or something to try.

I'll begin with taking the truck(F150 V8 5.4L) in because it had been misfiring but not dropping a code. The mechanic that has done a fair share of work for me said he'd try replacing the plugs first, since they had never been done(105,000 miles). So I agreed. To my surprise NONE broke! Win.

However after getting it back there is the smell of either fuel or exhaust in the cab now when stopped. You can clearly smell it with the hood open when smelling around the motor, but I'll be dammed if I can find the source.

I had him re-torque the plugs as I've read this to be the cause. He did, but no fix. The fuel rails and injectors all look dry. He originally torqued them to 11ft/lbs. I'm assuming he did the same on the re-torque.

Yesterday it started skipping again. I was a bit annoyed so I gave it a touch of gas, enough that it tripped a code and engine light flashed briefly but went out. Code was a misfire on #4. I changed out the coil. Has acted fine. In fact just because I'm irritated, I changed all coils. So far so good. At the time of changing the coils I re-torqued the plugs as well to 300 in/lbs(25ft/lbs). At least I think. The scale was difficult to read. I set it about half way between the 240 and 360.

Still no success on getting rid of the smell. Replaced the exhaust manifold on the passenger side about a year ago. The driver side looks pretty ugly. However it is not making the typical "tick" sound like the other side did. Could it be leaking anyway??

I realize this is a fairly long read, but just trying to give all information.

Also should the coils smell of fuel? They all did when I changed them...

Thanks for any and all help!!!

 

Anyone have an idea about this?

 

This is the first time I saw your post.
It would be helpful if you could be a little more specific.
Exhaust smells different from Gasoline.
If possible to help locate a possible exhaust leak try a piece of hose and with one end at your ear try moving the other end of the hose all around the exhaust manifolds, both, and if there is an exhaust leak you will be able to hear it much better using the hose. What year is the vehicle?

 

It is an '05. Just replaced all injectors and fuel filter today because the misfire was back. Test drove for about a 20 min. Ok for now.

To tell you the truth it smells like gas to me. Not exhaust. But if it was the manifold would the smell be more like gas than the smell coming from the muffler? That has a distinct smell in and of itself.

A question I asked the mechanic was, "should the coil ends smell like fuel?" He couldn't answer that. When I replaced all the coils a majority of them smelled like fuel. I was thinking that they shouldn't smell at all. But maybe I'm wrong.

I am going to try and pull the plugs myself and see if notice anything around the seat.

For what its worth the smell is coming from the right(drivers) side. The left side smells like, well, what I would say normal.

 

Hey b sheen my neighbors 05 is doing basically the same thing along with an ABS light after a new battery. Anyway he's got 103K on his and I changed coil pk #5 but still misses especially on the highway. I noticed that you changed all plugs and coil pks and still a miss.if you find out what's causing it please let me know : thanks beaglerock

 

Btw I changed CP #5 because the code said 5 was bad.

 

Something you guys haven't looked into yet
When possible if you get a code for a bad coil , switch it with one on the other side of the engine. For some reason Fords don't always provide the correct cylinder with the misfire without a special scan tool to look deeper into counts etc. If the misfire moves to the new position that coil is defective.
Some of aftermarket stuff is OK, but an awful lot is not, right out of the box !
Your chances of getting a good coil are better if Motorcraft is used.
If you know the coil is good and the injector is working properly then you may need to remove the valve cover and look carefully for a broken valve spring for the cyl with the misfire. Not uncommon. There are some 5.4s out there that were butchered to run OK temporarily just so the owner could unload it because of the spark plug problems. If you had it since new that would not enter into the picture.