Cylinder 2 misfire cause found...what?

Joined
Jan 27, 2004
Messages
4,131
Location
Richmond, VA
The adventures of BIG FLEXY continue. Last week she got a new wheel bearing and i guess she wanted some more drama. Yesterday i was at work and wife called me saying her 2009 Ford Flex was bucking like a bronco. I have replaced the same ignition coil twice on this car, both times using a cheap coil from amazon. She is 60 miles from home when she makes this call and I am still at work and cannot leave for hours. Told my wife who doesnt know much about cars to roll up her sleves because she is gonna replace a coil. She goes to Advance Auto in a small town and they read the code. Uh oh, not the cheapchina coil that I have replaced before, the misfire is cylinder 2 on the backside of the engine and you have to remove the intake to get to those coils. My daughter and her fiance are nearby and i walk them how to pull the coil out and put in the new NGK coil she bought from advance. (Yes i assumed it was a coil). They button everything back up big Flexy still has a bad misfire. Told wife i will have to drive out there tomorrow and fix it. Fast forward to this morning and we drive out to Farmville (60 miles away) and I go to work, confident we will be on the road in under an hour. Move some plugs around expecting to see the code move, nope stays on cylinder 2 regardless of which coil i put there. Pull the spark plug, it looks fine. 2 hours later, i decide to drive it home and work on it after i google and youtube how to diagnose this. Decided it was probably the fuel injector based on a bunch of facts I am leaving out of this post. Saw a Chris Fix video showing the test of an injectors impedence would probably confirm my suspicion. I tested the impedence of 2 injectors up front and then go for the injector on cylinder #2. Nada, no reading...what? Try it again, the sun is going down so i get the wife to hold a flashlight there and pull out the prongs to my mulitmeter....there is oil all over the prongs....what? Yes oil, as in 5w30. Look down in the connector, oil is pooled in there. Use several paper towels to get the oil mopped up and clean off the connectors, still no reading on the multimeter. Tomorrow I guess Im going to replace a fuel injector, but HOW IN THE WORLD DID OIL GET IN THEM? I realize this a direct injection car...but oil forced its way back up into fuel injector? No oil dripped into the connector because the top of the connector was dry. Do i have bigger problems than a failed injector? Thanks for reading my story, not sure I want to know what Big Flexy has in store for me next weekend.
 
20210306_174640.jpg
 

Attachments

  • 20210306_174630.jpg
    20210306_174630.jpg
    59.5 KB · Views: 119
  • 20210306_175434.jpg
    20210306_175434.jpg
    78.2 KB · Views: 111
  • 20210306_175412.jpg
    20210306_175412.jpg
    91.4 KB · Views: 119
Wow that sucks. Sorry that happened to you. I’ve never dealt with oil coming back into the injectiors. Wonder if it could be seeping down from the valve cover? Or the o-ring around the injectors maybe?
 
The adventures of BIG FLEXY continue. Last week she got a new wheel bearing and i guess she wanted some more drama. Yesterday i was at work and wife called me saying her 2009 Ford Flex was bucking like a bronco. I have replaced the same ignition coil twice on this car, both times using a cheap coil from amazon. She is 60 miles from home when she makes this call and I am still at work and cannot leave for hours. Told my wife who doesnt know much about cars to roll up her sleves because she is gonna replace a coil. She goes to Advance Auto in a small town and they read the code. Uh oh, not the cheapchina coil that I have replaced before, the misfire is cylinder 2 on the backside of the engine and you have to remove the intake to get to those coils. My daughter and her fiance are nearby and i walk them how to pull the coil out and put in the new NGK coil she bought from advance. (Yes i assumed it was a coil). They button everything back up big Flexy still has a bad misfire. Told wife i will have to drive out there tomorrow and fix it. Fast forward to this morning and we drive out to Farmville (60 miles away) and I go to work, confident we will be on the road in under an hour. Move some plugs around expecting to see the code move, nope stays on cylinder 2 regardless of which coil i put there. Pull the spark plug, it looks fine. 2 hours later, i decide to drive it home and work on it after i google and youtube how to diagnose this. Decided it was probably the fuel injector based on a bunch of facts I am leaving out of this post. Saw a Chris Fix video showing the test of an injectors impedence would probably confirm my suspicion. I tested the impedence of 2 injectors up front and then go for the injector on cylinder #2. Nada, no reading...what? Try it again, the sun is going down so i get the wife to hold a flashlight there and pull out the prongs to my mulitmeter....there is oil all over the prongs....what? Yes oil, as in 5w30. Look down in the connector, oil is pooled in there. Use several paper towels to get the oil mopped up and clean off the connectors, still no reading on the multimeter. Tomorrow I guess Im going to replace a fuel injector, but HOW IN THE WORLD DID OIL GET IN THEM? I realize this a direct injection car...but oil forced its way back up into fuel injector? No oil dripped into the connector because the top of the connector was dry. Do i have bigger problems than a failed injector? Thanks for reading my story, not sure I want to know what Big Flexy has in store for me next weekend.
Direct injected? That looks like a Bosch PFI to me. There is no oil inside these injectors and no way for it to enter from the bottom so oil entered through the harness into the connector or some sort of dielectric grease or someone used Vaseline in place of it at some point for god knows what reason.
fortunately a new OE Bosch injector is cheap, under $50.
 
That is port injected, not direct. The EcoBoost 3.5 would be direct injection but was not offered in 2009 in a Flex.

Check the oil pressure sender connector. I have seen the senders fail and send oil through the harness. We literally just had a Super Duty that did it this week, the harness was obsolete and the truck was no longer able to be registered as a commercial vehicle in California.
 
That is port injected, not direct. The EcoBoost 3.5 would be direct injection but was not offered in 2009 in a Flex.

Check the oil pressure sender connector. I have seen the senders fail and send oil through the harness. We literally just had a Super Duty that did it this week, the harness was obsolete and the truck was no longer able to be registered as a commercial vehicle in California.
That has to be it....
granted I've only done plugs on 2 of these engines, but... there's no other way for oil to get there....

Wow that sucks. Sorry that happened to you. I’ve never dealt with oil coming back into the injectiors. Wonder if it could be seeping down from the valve cover? Or the o-ring around the injectors maybe?
nope.. the top of the valve cover is visible at the bottom of the big picture... the intake runners are top center of the valley, all 6 in a row, right between the Fuel rails...

 
I read that this engine was direct injection a long time ago and never really thought about it until now. After reading more about port injection vs direct injection, I think I know more about fuel delivery than I ever wanted to. It also made me realize how little i know about cars that i have owned for years and years🙈
 
Definitely not a direct injected engine. I had to look twice for the oil you were talking about in the harness. Any chance someone spilt a little oil while doing an oil change or repair? Doesn’t seem like a lot of oil.

And how many miles?
 
I read that this engine was direct injection a long time ago and never really thought about it until now. After reading more about port injection vs direct injection, I think I know more about fuel delivery than I ever wanted to. It also made me realize how little i know about cars that i have owned for years and years🙈
Be glad it’s not direct injected, if it were you’d be spending a lot more money on the injector and half the day trying to get it out. That’s if you could get it out.
 
Definitely not a direct injected engine. I had to look twice for the oil you were talking about in the harness. Any chance someone spilt a little oil while doing an oil change or repair? Doesn’t seem like a lot of oil.

And how many miles?
118k miles, and the connector pic was after i cleaned it out for 5 minutes, the paper towel pic is one of about 10 paper towels i jammed in there
 
118k miles, and the connector pic was after i cleaned it out for 5 minutes, the paper towel pic is one of about 10 paper towels i jammed in there
Well, I’m not sure where exactly the second cylinder is on that engine, but there’s no chance someone spilled oil? That would make the most sense.

When you pull out the injector take a look at it...is there al it if oil going through the inside of the intake? Did oil come out between the injector seal and perhaps cover the injector? Or the valve cover gasket leaked...or lower intake gasket?

Really strange situation you have yourself here. I have seen oil track up wires and inside a connector, but that shouldn’t happen on an injector (I’d think).
 
Put in a new injector today and the misfire is gone 😃...but there is a really low frequency hum coming from somewhere, im too worn out to look at it anymore.

Took a really good look at the injector and wires, connectors and im stumped. The oil that was in the connectors was like really used and smelly oil....maybe it was blowby from the pcv? No idea. It was not oil that was spilled since it is under an intake, and on the backside of the engine. In addition i dont think it tracked up the wires since they are clean as new and the outside of the connector was dry and clean also, zero hint of any type of oil.
 
I'm pretty certain that electrons flow better through the wire pipes with a good lubing of motor oil. Otherwise they slow down too much and get lazy before doing their job.

Source? I'm an electron lubing expert. :geek:
 
I’ve seen oil in connectors at engine control units before and when traced back it comes from a sensor say oil pressure switch that has failed allowing oil up the harness. Does this engine have a variable pressure oil pump with a control valve in the sump? Check the ecu for oil next
 
Back
Top