loss of power no one can tell me what's wrong

[bobross]

Hello!

I have a 2010 expedition EL.

About 2 years ago I was going up a steep hill and noticed a loss in power, then a flashing engine light and stuttering, so I pulled over, turned off ignition for a minute or two and restarted. No engine light and power seemed to be OK. I took it to an auto parts store to use their computer and it showed a misfire on one of the cylinders.

I continued to drive it but noticed it often would hesitate when accelerating sometimes and going up even small hills would often lose power like it's being choked of fuel/air. So I took it to my local shop and they said they couldn't replicate the issue. (of course there's no hills nearby and the stuttering was intermittent sometimes).

Searching youtube and google I found that the mass air flow sensor might be the culprit. So I took it out and cleaned it with MAF cleaner and BAM! it drove perfect again. Perfect idle, plenty of power, handled hills no problem. Then maybe 6 months later it started stuttering on hills again, slightly rough idle, etc. After cleaning the MAF sensor a few times I bought another MAF sensor (refurbished from NAPA), and still notice the problem. Now it struggles up almost all hills unless I slowly accelerate and don't give it too much. Steep hills I have to put it in 2nd gear, then 3rd, otherwise it will lose nearly all power going up.

I took it to another local auto shop and they couldn't replicate the problem (not driving it up any hills of course). And my two local ford dealerships are a huge pain in the *** to deal with, making you wait 2-3 weeks for an appointment and when I tried they couldn't even check it that day so I gave up. They'll probably not replicate it either as they won't drive it up a hill.

So what the heck could this be? I replaced the plugs 4 or 5 years ago for reference. Being that the first time I cleaned the MAF sensor it ran perfect suddenly for months, does that sound like it could be my problem and I just got a faulty replacement sensor maybe?

Any ideas?

(128k miles, meticulously maintained until 50k, then minimal maintenance since). Not sure what plugs I have in I just went with whatever the autoplace recommended. I know it doesn't throw any codes and everything runs fine until you give it acceleration on hills.

 

[stamp11127]

Welcome to the site.

Until you have active codes the list of "could be's" is a mile long. How many miles are on the clock? What maintenance and repair work has been done in the past? How many miles on the "new" plugs, which brand?
How hot are the cats (are they plugged)? And the list goes on.....

Invest in a decent scanner and you should be able to read the values from each sensor. That would tell you if the MAF is sending bad data.

We try to get members out of the parts tossing mode using diagnostic troubleshooting to verify a failed part before replacement.

 

[bobross]

thanks. unfortunately it doesn't show any codes. I updated the post with info, 128k miles, not much maintenance after 50k other than oil changes, transmission fluid leak repair, new plugs in 2014-not sure what brand. Probably 40k on the new plugs).

 

[JExpedition07]

Obvious but you aren’t running the original air filter are you?

 

[bobross]

I change it every year.

 

[Blksmk]

Check your starter. Ignition system coils ground etc

 

[Flexpedition]

Although the post implies a strong discord for dealers, I'm sure a Ford technician driving the truck uphill, you riding shotgun and his laptop capturing streaming live data, will be the quickest way to pinpoint whatever the trouble may be.

It'll be a pretty strait forward request - your guy drives with me to this steep hill nearby, or no appointment will be needed.

 

[stamp11127]

You can force codes by recreating the conditions necessary that produces the stumble or lack of power. Once it starts having issues just keep it occurring until it logs the codes. If it doesn't then the engine is operating with in parameters. In that case it would be something the pcm doesn't monitor.

 

[stamp11127]

Blksmk, I'm curious how the starter would produce a lack of power once the engine is running.

 

[bobross]

Although the post implies a strong discord for dealers, I'm sure a Ford technician driving the truck uphill, you riding shotgun and his laptop capturing streaming live data, will be the quickest way to pinpoint whatever the trouble may be.

It'll be a pretty strait forward request - your guy drives with me to this steep hill nearby, or no appointment will be needed.

I would prefer taking it to a dealer since they (should) be the most experienced, but the problem is my local dealer schedules service 2-3 weeks out and when I did that recently I waited all day only to be told they couldn't take a look at it. So it's just really frustrating.

Knowing that they can drive and have a computer hooked up at the same time that will show what's going on would be incredibly helpful, is that normal for dealers to do?

 

[stamp11127]

Any competent repair shop will have an EST (electronic service tool) that will capture live data. If they don't then they are parts tossers at best.

Any OEM dealer that has to schedule repairs that far in advance indicates to me to find another one.

Do you have any performance shops near you that have a chassis dyno? If so, they can program the dyno as a heavy vehicle which will put a good load on the vehicle. Who needs hills?

 

[mrbadwrench]

If you accelerate hard on level ground, will it show the problem? Does it matter if the fuel tank is full or half or near empty? I remember a 40 year old story about a ping pong ball in a fuel tank.

 

[rwmorrisonjr]

Could be a symptom of the VCT solenoids going bad. Unplug them (they're located on the valve covers at the front of the engine). If the engine runs fine and produces adequate power, then they're the culprit and need to be replaced. The age and self-reported maintenance history points in their direction. Replace them with OEM solenoids only!

At that age, you're coming due for the dreaded timing chain rattle as well, so you might want to start saving for the timing chain/cam phaser/optional oil pump replacement if you want to keep your truck for the long term.

 

[bloodhound]

You're on original coils?

 

[bobmbx]

If you accelerate hard on level ground, will it show the problem? Does it matter if the fuel tank is full or half or near empty? I remember a 40 year old story about a ping pong ball in a fuel tank.

Unfortunately for us old school pranksters, they solved that issue decades ago.

 

[Muddy Bean]

Could be evap system. My truck is doing the same thing and it’s a one way check valve in the evap system that’s toast.


Sent from my iPhone using Tapatalk Pro

 

[coolzzy]

Original coil packs? I'd start there, it's a pretty common complaint in the F150 world. The coils can go bad and not show any outward physical signs of failure. A blinking engine light means cylinder misfire, if it were me I'd be changing out all the plugs and coil packs. Use oem Motorcraft spark plugs, but I've had good luck with some of the cheaper brand coils on Amazon or ebay. Usually 1 in 8 will be bad out of the box or close to it so don't toss the old ones as you might need a spare while you warranty one of the new ones. How often do you change your oil? Long OCIs mess with the VCT solenoids and clog their screens. When they go bad, all sorts of power related issues crop up as well as noises. Hopefully you're changing oil every 5k miles with either Motorcraft 5w30 blend or a quality synthetic....

 

[Powermax]

What about a fuel filter replacement?

 

[Scott Carden]

Sounds like the timing is going off and the ecm is causing it to go into limp mode. How many miles are on it? If it’s over 75,000 it’s likely to be the vct. As the engine struggles and gets hotter oil thins out and can cause excessive blow by a leaky cam timing advancer. The timing will go off, computer try’s to correct and can’t so it goes into limp. Shut it off turn it back on and the computer resets as it no longer detects the issue at idle or normal driving conditions.

 

[Trainmaster]

Anyone consider diagnosing the problem?

Or you can change the plugs, boots, coils, variable timing sprockets, timing solenoids, chains, chain guides, catalytic converters, oxygen sensors, cam sensor, air and fuel filters, pcv valve, purge solenoid and a whole bunch of vacuum hose and see if that helps.