Ford Truck Enthusiasts Forums - Modular V8 (4.6L, 5.4L)

F150 5.4L wiring

jt24152 — Thu, 14 May 2026 01:38:04 GMT

I have a 2008 F150 5.4 flex. I recently had cylinder 5 issues. Turned out there is a wiring issue. On cylinder 5 coil harness pins, when performing a continuity the ground and control wires so continuity (not good).
I have traced it out as far as I can find info for. I am looking for wiring pin out on c139. The 16 pin breakout connector off the, I believe is C175E....
I have traced the ground (green/red) from the coil to the harness. However the control wire on cylinder 5 (green/yellow) is also tracing back to, I believe pin 16. Which none of the other cylinders are doing. Any advice on tracing the short further would be appreciated.

4.6 Early and Later Model

fordtrucksforever — Wed, 13 May 2026 04:33:16 GMT

Bad motor in 2007 F150 with 4.6 two valve engine. I have a donor engine from 98 model E100. There are differences in the heads, but I think the 07 intake will still fit. Can someone verify if the swap will work? I am hoping the 98 long block will swap over with 07 bolt ons.

The intake runners are more round and smaller on early model. The 07 has larger squarish openings. If the injectors are in same location, it appears like the 07 intake and gaskets will work.

The 2007 engine had only water in block during a very hard freeze. Crankcase filled with water. So far I have not found where it is leaking from. The radiator completely emptied into oil. I drained 3 1/2 gallons of white sludge from oil pan. Engine only ran for a few minutes as water mixed. Spark plugs show no signs of water intrusion. I am down to either a cracked block or one of the cylinder heads as the problem. Maybe an outside chance of front freeze plug on head could have popped out.

I have both engines stripped down ready to pull out of each vehicle. Any suggestions would be greatly appreciated. Thanks

PCV / Heater Hose Installation

cstanley92 — Thu, 23 Apr 2026 14:19:26 GMT

I inherited my late brother's 2003 5.4L F-150 and doing some clean up on it. I replaced the PCV and the hose. I thought I had it all hooked up correctly but the truck seems to be misfiring. Can anyone point on the touch points for the two long hoses that come off the PCV itself? I have the main PCV in the valve cover and 90* to the back of the intake... The other two long ones are connected to the two nipples off the throttle body. One has about a 90* bend and the other doesn't but the hose seemed to fall exactly in place, however before I removed the old hoses, nothing was connected there before. Any help would be appreciated.

I stole this pic for reference, but it seems like there may be some variant of the TB