Power loss, 2005 5.4, any ideas?
08-07-2019, 12:21 PM
#31
Triton 5.4 3v powerloss when accelerating or under a load
After searching and reading a bunch of posts, I decided to ask your help in solving a difficult to diagnose power loss issue in my 5.4.
2005, 170k miles, bought new, maintained better than recommended. Not a mechanic by trade but I can do a lot. Rebuilt a dozen or so engines, half as many transmissions, restored many cars, do own maintenance on everything I own.
Problem;
I have a power loss that feels just like the cats are 80% plugged. Slow takeoff, takes off better if gradually giving the gas. Punch it at speed it will almost slow down, it seems that way but does gradually accelerate. Will run speeds up to 60. May go higher just haven't tried it.
No unusual engine noises
No codes
What's be done;
- New Fuel Filter
- New Air Filter
- Ran a couple of cans of Seafoam through it
- Cleaned mass airlow sensor (it was clean but cleaned it anyway)
- Cleaned throttlebody (not really related to problem but it needed cleaning)
- New Plugs, Autolite
- Checked coil packs via ohm'ed out, all have similar values. (.6M input to output. 5.5k across inputs- Boots are soft, look perfect, dielectric used
- Fuel pressure per FORD manual is 35 to 70 range. I had 68 at key on. leakdown was to 65 after one minute. Strapped gauge to wiper and road tested and constant 55psi observed.
- Flow tested cats by drilling 3/16 hole in front and behind cat, flow seemed the same to me. welded up holes.
- Spent a lot of time reading FORD manual, posts etc, to no avail
I do not have an expensive scanner so I did all I thought I could do. Put my tail between my legs and carried it to local and largest FORD dealer we have. I live in central NC.
They kept it 4 days doing the following:
- Reflashed the PCM
- Cleared all learned codes
- Checked many other things that they said were good.
- Said nothing shows up on scanner as a problem.
- Boroscoped the cats and said they were bad and needed replacing. I questioned this but the mechanic said they were melting and broken up (he lied by the way)
- Taken to great welder/exhaust specialist and had new cats installed, there was nothing wrong with the old ones once they were removed and inspected
- Had new muffler and duals ran (I had wanted to do this and thought now is the time and I can eliminate the old muffler collapsing as an issue)
Took it back to FORD and "#$&$%" (gripped)
- They kept it another 2 weeks checking everything (their words, not mine)
- Said it had bad carbon deposits in cylinders causing spark knock which was retarding the timing
- They did a “power flush” of all cylinders and installed new spark plugs
- Problem is NO different than before but they called and said to come get the truck because they did not know what else they could do to it. They hold to the carbon issue and said keep throwing fuel cleaner in it. They did not charge me anything, parts or labor, and cut me a check for the new cats since they so adamantly instructed replacement was necessary.) (That was great but I still have a truck that has a power loss problem)
Since I got it back I have done the following:
- Poured water down the throttlebody to breakup any carbon in the cylinders. May sound hokey to some but if you ever pulled a head that had a coolant to cylinder leak or had a water injection system on a drag car, you know it works.
- Ohm’ed out the knock sensors and they were 4.5M ohms which is FORD spec
- Bought new knock sensors and did not install but hooked them up, insulated them and taped them to the firewall. If spark knock exist I would hear it and the engine would be running better. Neither occurred which indicated carbon buildup is not the issue. (hope I can return them?)
- Decided after all my reading to replace the VCT solenoids. FORD had a follow-up part number so some changes were made and a lot of people had problems with these. Sounded like a good pre maintenance thing to do to me. This was the first time I have seen inside the engine, it was incredibly clean. Always used Motorcraft Syn and changed oil every 3k to 4k miles. VCT solenoids were intact, meaning screens were in place and all looked perfect. (NO difference in performance after installing new ones.)
I have 2 more things I plan to do but I am running out of ideas and thought I would start a post to see if there is some poor soul like me that has had this problem.
Thanks for any help.
2005, 170k miles, bought new, maintained better than recommended. Not a mechanic by trade but I can do a lot. Rebuilt a dozen or so engines, half as many transmissions, restored many cars, do own maintenance on everything I own.
Problem;
I have a power loss that feels just like the cats are 80% plugged. Slow takeoff, takes off better if gradually giving the gas. Punch it at speed it will almost slow down, it seems that way but does gradually accelerate. Will run speeds up to 60. May go higher just haven't tried it.
No unusual engine noises
No codes
What's be done;
- New Fuel Filter
- New Air Filter
- Ran a couple of cans of Seafoam through it
- Cleaned mass airlow sensor (it was clean but cleaned it anyway)
- Cleaned throttlebody (not really related to problem but it needed cleaning)
- New Plugs, Autolite
- Checked coil packs via ohm'ed out, all have similar values. (.6M input to output. 5.5k across inputs- Boots are soft, look perfect, dielectric used
- Fuel pressure per FORD manual is 35 to 70 range. I had 68 at key on. leakdown was to 65 after one minute. Strapped gauge to wiper and road tested and constant 55psi observed.
- Flow tested cats by drilling 3/16 hole in front and behind cat, flow seemed the same to me. welded up holes.
- Spent a lot of time reading FORD manual, posts etc, to no avail
I do not have an expensive scanner so I did all I thought I could do. Put my tail between my legs and carried it to local and largest FORD dealer we have. I live in central NC.
They kept it 4 days doing the following:
- Reflashed the PCM
- Cleared all learned codes
- Checked many other things that they said were good.
- Said nothing shows up on scanner as a problem.
- Boroscoped the cats and said they were bad and needed replacing. I questioned this but the mechanic said they were melting and broken up (he lied by the way)
- Taken to great welder/exhaust specialist and had new cats installed, there was nothing wrong with the old ones once they were removed and inspected
- Had new muffler and duals ran (I had wanted to do this and thought now is the time and I can eliminate the old muffler collapsing as an issue)
Took it back to FORD and "#$&$%" (gripped)
- They kept it another 2 weeks checking everything (their words, not mine)
- Said it had bad carbon deposits in cylinders causing spark knock which was retarding the timing
- They did a “power flush” of all cylinders and installed new spark plugs
- Problem is NO different than before but they called and said to come get the truck because they did not know what else they could do to it. They hold to the carbon issue and said keep throwing fuel cleaner in it. They did not charge me anything, parts or labor, and cut me a check for the new cats since they so adamantly instructed replacement was necessary.) (That was great but I still have a truck that has a power loss problem)
Since I got it back I have done the following:
- Poured water down the throttlebody to breakup any carbon in the cylinders. May sound hokey to some but if you ever pulled a head that had a coolant to cylinder leak or had a water injection system on a drag car, you know it works.
- Ohm’ed out the knock sensors and they were 4.5M ohms which is FORD spec
- Bought new knock sensors and did not install but hooked them up, insulated them and taped them to the firewall. If spark knock exist I would hear it and the engine would be running better. Neither occurred which indicated carbon buildup is not the issue. (hope I can return them?)
- Decided after all my reading to replace the VCT solenoids. FORD had a follow-up part number so some changes were made and a lot of people had problems with these. Sounded like a good pre maintenance thing to do to me. This was the first time I have seen inside the engine, it was incredibly clean. Always used Motorcraft Syn and changed oil every 3k to 4k miles. VCT solenoids were intact, meaning screens were in place and all looked perfect. (NO difference in performance after installing new ones.)
I have 2 more things I plan to do but I am running out of ideas and thought I would start a post to see if there is some poor soul like me that has had this problem.
Thanks for any help.
5tr
The following users liked this post:
o6S1D9e (12-07-2021)
08-07-2019, 03:46 PM
#32
Try the intake actuator... I had a huge power loss with no codes...i was looking at a Chilton manual on f150.. Saw the intake actuator and link setup ..i didnt even know it existed... I broke mine free and did a seafoam intake spray clean. And whal - La. All fixed
5tr
5tr
08-07-2019, 06:59 PM
#33
....i figured he wouldnt need my thread....i just wanted to post it to any thread with this issue.....i notice there were alot of comments with the same symptoms but no one never really gave a all good fix....the all stated.....plugs,cods,pcv,phasers,vct's,maf' o2's...but no one ever said what worked... So i figured i would just put the info out there
The following users liked this post:
o6S1D9e (12-07-2021)
The following users liked this post:
o6S1D9e (12-07-2021)