harm63

I tried to search through the forum to find a similar thread, but no luck. If y'all can point me in the right direction, I'm more than happy to read an existing thread that covers the following:

2002 F150 5.4 4x4 screw
208000 miles

recently changed all spark plugs and boots (didn't change any COP's)...
was getting rough idle and vibration when in overdrive intermittently and figured it was time to replace the plugs... best way for me to describe it is that it acts like it cuts out like a misfire or "dead cylinder" if that makes sense. I can trigger the same issue when I try to accelerate as well... just acts like a spark plug or COP isn't functioning. When I get it to cruising speed, it acts normal for the most part (I only know this because the symptoms / issues occurred when driving back home from work). the CEL i have currently is only for Bank 1 and Bank 2 lean.... the CEL diagnostic machine didn't detect a misfire at all... literally said "Misfire = no." I've also recently replaced the battery on it (wouldn't figure that matters, but wanted to throw it out there).

I'm at a loss. I had an issue after replacing the plugs where two fuel injectors were leaking.. that's since been fixed. Thanks in advance for your help.

sistahazel

Are you loosing any water? You could have a cracked Intake manifold leaking water into the cylinder area. many of them models have plastic manifolds that are susceptible to fractures resulting in a leak which in-turn can cause misfires.

Carcrazygts2

Check the rubber elbow on the back of the intake that connects to the pcv hose.

harm63

ah, didn't think to check that. So if that particular piece had a hole / crack in it, it'd cause those "misfire" symptoms huh... if that's the case, couldn't I (in theory) wrap it in duct tape to test it out or...?

harm63

I did notice a water spot under the engine area.. but haven't been able to find the source of it yet. I chalked it up to condensation from the catalytic converter after cooling down outside.

JCR 56

Sounds like a weak COP to me . They usually don't trip a code when they first start going bad. They usually will miss when trying to accelerate after shifting into overdrive.

harm63

sorry for a long delay in following up on this. I have a "Bank 1 and Bank 2" lean code... and looks like I'm leaking radiator fluid into the "valley" of the upper part of the engine (under the intake).

At this point and based on research I've continued to do, I'm leaning towards this being a jacked up upper intake manifold that needs to be replaced along with possibly a hose leaking underneath the intake.

this will be my first time tearing off the intake... definitely not looking forward to it.

Tom56

I did the intake thing recently. It's not terrible, take your time. I took lots of pics when removed stuff so I could put it back together.

harm63

well.... got the intake manifold replaced finally. Now, I have a cylinder #4 misfire happening. Replaced the COP on it... getting the same shuttering of the engine, only no CEL at this point. I now smell either coolant or something...

Jbrew

Yea, you still have the same problem you had to begin with. It's a low grade misfire. They don't always show up in the KAM because your misfire monitor hasn't picked it up yet. The misfire count isn't high enough yet.

Your description of the miss is dead on for a bad coil with shorted winding turns.

At this point, it's just better (integrity wise) to change all the coils out at the same time with good ones.

There's only two manufacturers on the market who make Ford spec coils for your engine. - That's Motorcraft and Visteon which are identical builds and thermal protection. So either or and you get at least another 100,000 out of them.