I have an 05 4x4 lariat 5.4 that has a pinging problem under load an falls on its face above 3,000 rpm. Bought it from car max and after I bought it it had this issue. They replaced the phasers and spark plugs. Ran great until 3 days ago (4months since the repairs). I've only put 3k miles on it since then and the problems are back. I pulled ALL the plugs to make sure they were actually changed by the dealer and not fouled out. They we're good. I searched all over for possible vacuum leaks. None noted. I even changed fuel filter in case it was clogged and starving the motor of fuel on the high end. No joy. It throws no trouble codes and no check engine light. Coincidentally, all this started the day after I changed my oil to royal purple 5w30 instead of 5w20.

Is there anything else that could be causing this issue? Lack of power above 3k and pining under load? Maybe

 

Take your fuel pump module off the frame and check the back for corrosion eating away at the case and internals. Guess the Navigater one is better, just remove the threads. It sets off the frame some.

 

I think I've read about that a long time ago... It's worth a look... Thanks

 

Just took a look at the fuel pump module and everything seems good to go there... Any other suggestions??

 

Loosing oil pressure at the Phaser, cause of this the cam journals are wearing out and dropping off oil pressure not allowing the phaser to do its job correctly and advance and retard the timing. Not sure this is the problem with out looking at it but the only confirmed fixes are replacing the heads r running a thicker oil 15-40, hope this helps

 

I hate these engines soo much. Slower than time, way under powered, and not even reliable.

Not quite sure if that's my issue just yet. It does make sense but I'm still kind of thinking its a fuel problem?

Also correct me if I'm wrong, but in higher rpms, don't the phasers advance timing? So if I'm pinging, they must be advancing just fine.

Also, the truck is bone stock. No mods.

 

yes you advance under load and retard under hw driving. i have actually seen a pinging caused by a clogged up cat on a 3v. try loosening your pipes up and driving it.. took the guy working on it replacing the fuel pump, and plugs b4 trying loosening the cats, also the phasers will make tons of noise when not operating properly which would also cause it to fall on its face, The 3v is a decent motor if maintained very well from the first day, 1 or 2 skipped oil changes and you can be looking into some very costly repairs, cant tll you how many heads i have seen put on or i have put on in the past year on these motors.. this is why i have a 5.4 2v.. have you checked you fuel pressure?

 

Well I would graph the pids in real driving time when it pings and when not. Look to timing much above 35/38 degrees a lot. Check the Maf for ranging from .4 to over 11. Then look to your fuel pids. Check the filter and PSI. Look long and hard for a vacuum leak or 2. Make sure all vacuum works. First of all after the PID's put in higher octane gas. Being lean on both banks points to a induction air leak, but the Maf should pick that up and the motor should not start if bad enough. Maybe clean the Maf to. A clogged Cat will show a much lower running PID temp than the other, much lower than 1100 degrees F.

 

Just for the hell of it take the positive cable off the battery for a few mins and then re attach. It will reset the pcm and vct. Give it a try. Doesn't cost anything to try. I think you may have sludge build up either on the vct sol, or in the head. When the vct system fails it will sometimes favor advance. What got my attention is when you went from 520 to 5w30 oil. Won't set a code if build up on the vct sol is there. Anyway also check your vacum pressure and see what you have. If the cats are plug then you should see it. Does it smoke ? Like a rich mixture when you are on the throttle?

 

Thanks for all the great tips guys. The VCT solenoids were changed when the phasers were done. I pulled them out last night and verified to make sure they were actually replaced. They look new. The clogged cat is something I haven't thought of yet. I have an edge evo cs and it's on stock setting and I have been using it to check timing numbers. So far I will have to re look at what they are under heavy acceleration. I have "reset" the computer about 3 times by un plugging battery. Drove it around until p1000 went away. Still no joy even when p1000 goes away. I always use 100% 91 octane. Always the off chance of some **** poor fuel, but I don't it.

I'm thinking I need to look more into spark advance and wether one cylinder is running lean. It doesn't smoke or produce eye burning rich exhaust. And I have scoured the engine compartment for any vacuum leaks with no success.

Car max is going to look at it again for me. But they can't get me in until the 18th so I was going to try and narrow it down before hand and if it was something easy, just fix it myself. Coincidentally the 18th is the day I go out for my next deployment so I'm not quite sure how I'm going to work that one anyway. Thanks for all the tips so far guys!

I'm getting the gut wrenching feeling it's going to be a cylinder head.