4.0 misfire and engine knock

[Frdtuff]

Code reader says misfire in cylinder 1 and 6 and has a new knocking sound.

I bought my son his first car about 5 months ago. The car has 196,000 miles but the previous owner said it had 40k miles on a rebuilt. The car is in great shape as far as interior and exterior goes... Looks like new. The previous owner also said he replaced the spark plugs, wires and I think he said he replaced the coil pack but I could be wrong about the coil pack.

Anyway the car gets very bad gas mileage. I'd guess 8-10 miles per gallon. Last weekend we replaced the coil pack and upper manifold gaskets after codes pulled were misfire in cylinder 1 and 6 and lean bank 1 and 2. After those repairs we are now only getting the misfire codes for cylinder 1 and 6. And knocking sound is still there. It's not very loud but you can hear it and it's not as noticeable when accelerating but that could be because of engine noise... Idk. My son says it's still not getting good gas mileage and there is a strong smell of gas that fills the garage when warming it up or working on it... Yes the garage door is open.

Any ideas on this? Could there still be an exhaust leak? Would that cause a knocking noise? It's not a ticking noise... Its dedinitely a knock although something tells me it's not a rod, but I could be wrong. Could it be spark plugs, catalytic converter, fuel pump? I don't want to spend a bunch of money at the mechanic and would prefer to tackle this on our own and teach my son a few things about mechanics but this one has me scratching my head. :-/

 

[Nolastcallss]

following, i am having similar issue with my truck

 

[Turdle]

1-what is the fuel pressure at idle with vacuum removed from FPR?

2-Have you checked compression on cylinder 1 and 6?

a very common error made is the firing order. Are you positive you have the spark plug wires in the correct positions on the coil pack?

I am assuming this is a 4.0 OHV engine?

 

[koda2000]

1-what is the fuel pressure at idle with vacuum removed from FPR?

2-Have you checked compression on cylinder 1 and 6?

a very common error made is the firing order. Are you positive you have the spark plug wires in the correct positions on the coil pack?

I am assuming this is a 4.0 OHV engine?

Quite possibly your problem. Diagram of cylinder/firing order below...

http://ricksfreeautorepairadvice.com/4-0l-v6-ford-firing-order/

Engine (from front)
3 6
2 5
1 4

Coil Pack/wires
1 2 3
5 6 4

 

[J_C]

Is the OHV a waste spark ignition system? If so I would have though that reversing two plug wires would result in 4 rather than two cylinder misfires. Regardless it's definitely something I'd check.

Given the upper manifold gasket repair I would double check everything related to that, whether it be vac lines still disconnected or cracked, fuel injector connectors not plugged in good, and things you know but I would wonder about is whether you reused injector o-rings or any gaskets like for the throttle body. I've not done the manifold gasket(s) on mine and different engine anyhow, so I'm merely speculating that the fuel rail is pulled to do that.