Hey Guys,

I`m a newbie to this site but have read and researched alot about the issue I`m having and have hit a dead end and was wondering if anyone might have any ideas? I`ve got a 2005 f150 FX4 5.4 ltr with about 106,000 kms. I`ve only owned the truck for about 4 months, which really makes it frustrating.

I`ve done the 100,000 km maintenance schedule and am getting a constant PO303 warning. So far, I have replaced all the sparkplugs, put a new coil in cylinder 3, the fuel filter has 3000 km`s on it and just had the extended warranty work on the fuel injector in cylinder 3 done as well and am still getting the PO303 warning. The truck runs alright when it`s cold but when it warms up and I hit cruising speed, 80 - 110 km/h, the engine starts to shudder when the rpm`s are low (overdrive sets in). It also does this when cruising around town sometimes as well. When it starts doing this I let off the gas then step on it to kick down a gear to get over the shudder. Something else to note is that under hard acceleration (merging) the transmission will kick down but seems like it sticks in one of the gears a bit then almost seems to power through the issue, the truck seems to have lost alot of the power it has, I get little glimpses of the power every blue moon and miss it. I do have an aftermarket air intake and have checked the MAF, it`s still clean. This issue started before the intake was installed.

Any ideas guys would be greatly appreciated.

 

have you did an injector service at all?? perhaps #3 injector is sticking and causing grief?? i wonder about the throttle position sensor (TPS) but not sure if it would cause that code... i don't think so...

 

Have you had a compression check done? It should be done on all cylinders for comparison. You could have a weak or broken valve spring.

 

I haven`t had a compression check done yet, I`ll try that this week.

Any ideas if this sounds like the cam or cam phasers? I have read that there is a definite issue with the cam or cam phasers with the 5.4 ltr but not sure if these symptoms are right for that issue?

One thing I forgot to say also is that my idle RPM is about 550 or 600, a little low but not sure if that will spark any other ideas on the potential problem.

Thanks again.

 

If it was a cam phaser problem it would affect one whole bank not just one cylinder. From what I have read on FTE the main complaint is noise with phasers. I don't know about the 3v but the 2v had some cam followers jump out of place especially in cold weather.

 

You may have a plugged catalytic converter. The drivers side cat on mine was plugged and it was throwing misfire codes, shuddering under load, no power etc... Changed the cat and everything cleared right up. A mechanic buddy had my truck on the hoist and I guess there was a huge temp difference from the front to the back of the cat. When I changed it I looked inside and it was plugged SOLID.

 

Do you think if I went for a ride I`d be able to do a touch test on the catalytic converter afterwards to see if I could feel for a difference in temperature?

 

well to test the temp for that cats your gonna need somthing other than you hand there to hot to touch and you will burn your self

 

I talked to the Ford dealer today and they said the fuel injector recall/ extended warranty was only for cylinder 3 on the 5.4 ltr engine so it is a known problem with that cylinder. I told her I was still getting a PO303 misfire cylinder 3 warning, and asked if she knew what else I might need to do that would correct the problem? She said she was going to contact Ford directly and ask what the process would be if the recall on that cylinder didn`t fix the problem, so hopefully I`ll get an answer tommorrow from her.
Any other ideas in the mean time would be appreciated, thanks to all who have given their advice so far.

 

I"m 99 percent sure thats crap.....i'm pretty sure it was that the injectors stayed open flooding the cylinder.....and on any of them......anyone else confirm this???

 

I was wondering the same thing, if anyone could confirm this, that would be a good thing for sure. The girl I`ve been dealing with at the dealership seems genuinely concerned and interested in resolving or helping resolve this issue so if I could get any confirmation then I`ll approach her on it tommorrow.

 

Hey FreeJay,

Your codes that were coming up when your catalytic was plugged, were they consistent or did they change up? I`m only getting a PO303 missfire and was wondering if that rang a bell or not? It does sound like you had similar symptoms, shuddering and such.

 

Did the engine hydrolock when the injector failed? You may have a bent rod causing low compression on that cylinder. Seen it many times with bad injectors. The extended coverage covers all the injectors but they have to fail first. Kind of stupid if you ask me because the injectors don't cost that much.

 

It just showed a misfire on #5, not sure what code that is. I only had it checked once. But now that I've changed the cat there is no misfire. Just something to check. If you have a infrared thermometer I think it would be a pretty obvious temp difference from front to back of the cat.

 

I`m not sure if the engine hydrolocked, what would happen/ symptom if it did? I just told the dealer all the things I had read and all the things I had replaced and they figured the injector must be bad and they replaced it, they never told me if it was stuck open or closed or if it even looked bad, one of those last minute fit ins before closing on a friday. Still waiting for Ford Canada to get back to the service department about what they think is happening.
Thanks FreeJay, I`ll see what I can do about getting something to check the temp on the cat.