Smitty67

Hi all,

I'm hoping you guys have some ideas because I'm all out.

My son has an 05 f150 4x4 with 5.4 engine. His truck started running poorly and had a check engine light. He had autozone check code and it had the well documented p0012 code. My mechanic checked oil pressure and it was 30 psi when warm. He suggested replacing the motor since it has 210,000 miles.

After reviewing information on the timing failures, I decided to replace the timing components. Upon removing the front cover, the passenger side chain guide had broken apart into many pieces. I dropped the oil pan, cleaned out the remains from the guide, cleaned the pickup screen, and replaced the oil pump since it was easy to do during the timing work. I replaced everything associated to timing, phasers, chains, guides, tensioner, gear, and both vct solenoids.

I got it all back together and left the crank sensor disconnected so I could prime the oil. I did work oil into the pump before installing btw. I cranked the motor for probably 30 seconds several times and it didn't register oil pressure via the pressure gauge/switch. I decided to quickly start to see if that primed and it did.

Now, the engine runs smooth and idles fine when cool. When it's warm, it looses power and seems to misfire. Really it's the original problem. No problem code at present but haven't driven more than 2 blocks since it presented the same problem.

Any thoughts? I'm concerned that an oil passage my be blocking since it didn't seem to prime like I thought it should.

Summers22

iTrader: (2)

Did you clean the oil passages when it was all apart? Also what brand of phasers did you use?

Smitty67

I used all motorcraft parts. What oil passages should have been cleaned? I followed the instructions from this youtube channel.

F150Torqued

^^ X2 on @Summers22 quesions. Additionally - what were the other prevailing conditions when that 30 psi oil pressure reading was obtained? (weight oil, engine temp or run time, RPM). Misunderstanding about oil pressure abounds, but I'm struck by the mechanic recommending a new engine if that was based on his verifying 30 psi oil pressure - unless that was with 20w50 oil and/or at 4000 RPM.


There aint many engines that will produce that at hot idle with 5w20.
As for your priming the oil pump with the starter for 30 seconds several times - that was FINE. Very few engines will build enough oil pressure at the RMP rate a starter can produce - perhaps 40 - 50 RPM. That will certainly circulate oil throughout the engine, but not generate enough pressure to overcome the oil pressure 'SWITCH' of 5-7 psi. 600 RPM idle speed is a completely different set of circumstances.


I do not think you have any oil pressure or passageway problems. I would be looking other directions for power, torque, or drivability issues. If there are no codes, drive the hell out of it and report the symptoms you detect then.

MaxLT

Wonder if you might have some weak coil packs or just some bad spark plug boots, they can act up when warm and not set any codes. Might be worth the $30 to replace them all with some cheap aftermarket ones and see if the problem gets any better.

Smitty67

Good suggestions. I think I will drive it more and see if it will throw a code or gives me a better clue. Thanks..

redfishtd

I held the pedal to the floor and it did the same thing . Holding pedal down will not let it start . I tried and tried to get pressure up . Its a myth, it won't get high enough to read . Mine started out real nice after that, and was smooth running .
I agree you may have some coil problems common to this engine . It doesn't want to set a code until it lasts 20 seconds .
Also the current advice is to run 5w30 in these engines . You should change the oil quickly to remove stuff that got in there when you had her open .
I use oem coils since I had bad luck with after market .

techrep

iTrader: (1)

Maybe check out the cats.. if it had been running like crap for awhile.

Smitty67

Now that would make sense.

Dirttracker18

Yup, a miss left untreated sends raw fuel into the cats where it burns and melts the cats internally causing them to plug.

Worth looking into.