2011 Ford Expedition XLT 5.4 3v - Idle issues about 60% of the time - No codes - Engine runs great otherwise

[ejs_flys]

I have a 2011 Ford Expedition 5.4 3v with 260k miles. Owned since new.

Issue is rough idle about 60% of the time. Rough in the seat of your pants. It never stalls but at times it appears to be close to a stall and other times it runs as smooth as it should.

No codes.

I'm 61 and work in high tech but spent the first 26 years of my life working in my fathers Auto Parts store and Machine Shop in North Central PA (best job I ever had). I do most of my own maintenance on my vehicles.

I purchased a Topdon Phoenix light 2 scanner that reviewed on Scanner Danner's channel.

I have replaced all the timing components with OEM as well as the Melling Hi Volume oil pump. This included chains, guides, tensioners , phasers, roller followers with the smaller oil holes, lash adjusters and both solenoids. Again all OEM.

I even replaced the throttle body with an aftermarket one because I broke some plastic on the original but it I was having idle issues with the original one as well.

I have replaced the Mass Airflow sensor as well but no change.

Oil is changed every 7k and now using 5W30 Mobile One instead of 5W20 Mobile One due to mileage.

I also use the Purolator Boss oil filters and change them every oil change.

I run Seafoam through the gas and oil on occasion to ensure the inside is clean.

When I had the valve covers off the top of the head was clean as if new. No sludge or discoloring.

I have replaced all the plugs, checked gap, torqued them to spec and replaced all the fuel injectors and COPs as well and all with OEM parts.

It runs great while driving. Acceleration is perfect and from zero to 60+ it runs better now than it did when new.

Gas mileage on a trip is over 19 MPG with 87 octane and over 20 with 93.

There is no knocking or any noticeable noise from inside the engine.

Short and long term fuel trims are low where they should be and normally hover around the low +- single digits.

I have spent a lot of money on this and have had one shop try to diagnose the issue twice but they came back with nothing significant.

The shop I used said they can sense a vibration at low RPM using one of their tools but to me that is hard to tell if there is a mechanical issue or a fuel or air or spark issue or even torque converter issue.

As far as I can tell the VCT error value hovers around 0 as well using the Topdon.

Relative compression is perfect.

Power balance is fairly good with no detectable misfires and the little bit of imbalance could be caused by one of the items noted above.

I watch Scanner Danner's channel and Ford Tech Makuloco. I followed his suggestions on the timing component refresh.

What I am looking for is if anyone knows of a good mechanic in the Northern Virginia area who is a good diagnostic technician who may even have experience with Ford 5.4 3v engines.

I have had many theories but so far none have panned out. I wonder if at low RPM the PCM is not giving enough power to the COPs at times to keep the idle smooth but not low enough to cause a code.

I am lost and have exceeded my diagnostic skills and I am not ready to throw the towel in yet.

Any ideas? I would appreciate.

Thanks!

 

[00000]

In my experience => seen spark plug wires that look fine yet don't function well when old .

An easy check is to find a really dark place @ night etc. I've had great luck with Bosch !

 

[ejs_flys]

Thanks for the suggestion but this has Coil On Plugs so each cylinder has it's own coil connected to the top of the spark plug. There are no plug wires and thus no distributor or rotor.

 

[Dennis_H]

Quick thought... Does it do it in park, or in drive with brake pushed. Just trying to see if maybe something with tranny?

 

[ejs_flys]

Thanks for the post. It does it in park and drive when at a stop. If I raise the RPM with my foot on the bake I don't feel it. If I accelerate hard, sometimes you feel it and others you don't. That is why I am so perplexed.

I have replaced the transmission with a rebuilt one through AAMCO (what a horror story) and I asked them to also replace the torque converter and they said they did but I can't believe them. I should have marked it. I recently added Lubegard from Dr. Tranny for torque converter shudder to the transmission fluid with no change. But it was also having the same rough idle before the transmission swap.

I had the oil pressure checked and it was good and strong especially with the new Melling Hi Volume Oil Pump. With the engine hot it was at 32 PSI at idle (592 PRM) and 62 PSI at 2k RPM. I had the shop test it since you have to remove the pressure sensor for the idiot light and connect a pressure gauge (Really dumb design here Ford). It's in an awkward place and not easy to get to laying under the truck on a creeper.

Lately the idle is getting a bit rougher at times than it was before and other times it runs like a well-oiled machine.

Can't hear or find any vacuum leaks using the ether method but tempted to try a smoke machine but since it is intermittent I'm not sure that would result in anything either.

Thanks for the post.

 

[Ryan L]

Maybe test for a failing engine mount or transmission mount?

 

[Dustin Gebhardt]

Maybe test for a failing engine mount or transmission mount?

I was thinking the same thing. Engine harmonics are a funny thing and what you can feel at low RPMs seems to melt away with higher RPMs (plus road motion).

 

[gasman5045]

Idle air control motor?

 

[mbtech2003]

Idle air control motor?

No idle motor in theese. It uses the throttle body.

 

[ExpeditionAZ]

Mine was doing something similiar. Turned out the fuel pump pressure was too high and I had to replace the fuel pump.