mwdaug

Hey all, really enjoying this site as a newb. My 05 fx4 crew has a misfire on number 5. I replaced coils with accel and plugs with motocraft. All old Ford coils tested fine as did new accel coils. Number 5 first noticeably failed under load of hill in OD and more pedal led to more knocking and pinging and less speed. Even with OD off I barely made it home and was down to 30mph on the grade for a period of time. All of this was preceded by what I saw as a lack of power in general. My truck had 100K on it when I bought it. Was not offroad or pulling anything. I know the PO. I put a Magnaflow on it, did the coils and plugs and installed a tuner in a weekend. It seemed much stronger and no hesitation that was I feeling before at OD shift points, low rpm. I pronounced it fixed. Two weeks later I have this failure on the way home and all signs point to low compression. Full test with leakdown scheduled for tomorrow. Dealer gave it a quick look, replaced number 5 injector, said it was stuck open (maybe) and said low compression, 1% leakage but couldnt say where. Said Phasers are knocking, replace long block, give us $8K. I said um no thanks, tell me the compression readings and then I can think about what to do and you are not getting the replacement work at those prices.

At 112K and only the number five misfire code showing, I am going to assume a valve problem on 5. Pulling the head, machine work, reinstall, plus chain, phasers and solenoids is maybe what 10 or 12 hours for a good mech? Dealer quotes 25 hours for engine change. It almost seems like a reman engine installed at a economical shop is maybe worth it compared to just doing the headwork and phasers on my engine? Now sure, if I have ring problems on 5 I dont see pulling my engine and tearing it apart for a rebuild to put it back in is going to save me anything.

All comments appreciated. Thanks.
Mike

mwdaug

I do have 35 inch tires and a 6 inch lift btw. That is important. Engine swap will be harder from what I see. Planning on gear change after I get through this engine mess.

mwdaug

Update - Local Indy shop found 160 psi on #5 which is pretty interesting considering major ford dealer says low compression, replace motor. Ford replaced injector 5 said it was stuck open and ext warranty covered it. I have 112K on it, thought that was out of warranty? Not sure if I believe them re the injector considering they obviously did not check compression. Indy shop says injector is not pulsing. Wouldnt this show another code besides P0305 misfire on 5? I did not hear back from the shop but guessing buying a new ECU or chasing through the harness seems like a wild goose chase. So now I have to wonder if my Cat is damaged? Timing chains are already slapping around and the shop has no interest in doing that work.

mwdaug

New PCM installed. Shop said it was "better". They also replaced #5 coil which was new with a Motorcraft. Waste of time. They said #4 cyl showed a little low on compression on the computer after they checked the balance. After all that, still P0305 code misfire after I try to climb a grade and it hits overdrive. Power falls off like crazy, valves are clacking like they are breaking to bits. I am afraid compression is really the issue and I need to see exactly how they are measuring compression. If you have fuel and spark to #5 and it holds 160psi then it has to fire! My dream of owning a bitching F150 sure has been tainted.