I have a 2015 f-150 with the 3.5L ecoboost turbo 6 cylinder. I have about 150,000 miles on it.

I get cylinder misfires frequently and replacing the ignition coil pack fixes the problem for about a month. After about a month I get the misfires sporadically and over a few months if happens more and more often. Then I replace the coil pack and it stops, for about a month.

I can't understand why replacing the coil pack fixes it for a while. It seems if it was the coil pack the replacement would fix it permanently. If it was not the coil pack then it should never work.

This is usually cylinder 2, but have also seen it a few times on 6 and once on 3.

This seems to happen more when its raining or wet.

Any ideas?

 

Yeah, I have a good idea. Buy a new truck. Really. You're about to spend some money on the truck to fix the issue and if you don't, I'll give you a hint, you'll be replacing the engine. Your problem is not the coil packs. The clue is #2 cylinder which is the one to usually lock up and it does it when it's wet. The issue is the intercooler for the turbo. In late 2005 production Ford finally fixed the intercooler making water which then migrated to the engine, The engines usually hydrolocked on #2 cylinder. Many of those engines went to junk quick. If you're daring you can take a very small drill bit and punch a hole in the bottom of the intercooler to let the water out. While buying a new truck may seem off the wall, the current 3.5 EcoBoost is not the same EcoBoost you have. It's a completely different engine and it's a pretty good setup. The only downside is Ford having issues with the 10 speed auto. Some trucks they can't seem to fix and some never have an issue- go figure. But you're looking at putting a revised intercooler on your truck and I wouldn't wait too long either. Almost hard to believe you haven't had issues with the engine laying down on you under full throttle scenarios while it rains or is wet. That's when the issue normally comes up due to the humidity in the air being condensed in the intercooler.

 

Thanks for the quick reply. A guy at the dealership told me this when it first happened. Its been 2 years and 60,000 miles so I thought he was wrong.

 

How do I find an intercooler that does not have the same flaw?

 

How many miles are on the spark plugs? Should be changed every 40k, regardless what the book says.

 

All 150k. I bought new ones this afternoon but not coil packs.

I've been reading about drilling the intercooler. Does that fix the problem after is has happened? Or will I still need to replace the coil pack?

Should I still before anything else?

 

If you have 150k on the spark plugs I'd be willing to bet that this will fix it, and you also will stop burning out coils. Excessive spark plug gap from wear is really hard on coils, and the Ecoboost is quite gap sensitive.

 

And Don, you don't have coil packs. You have 6 each COPs which is individual coils that sits on each plug. If putting new ones on the engine, use Motorcraft ONLY or expect issues. Performance COPs are a bad joke and don't work near as well as OEM.
Drilling the intercooler allows the condensate to blow out of the small hole. That should eliminate your issue. Just make sure the hole is at the lowest point of the intercooler.

 

I thought the intercooler issue was fixed before 2015?

 

The Ford revised intercooler came out as a late 2015 change.

 

It's hard to believe that changing the COPS was tried repeatedly without new plugs with that kind of mileage!

 

I was not on top of it. I got busy and just took it to a shop when I saw the engine light. It has been to three places and all just replace the coil packs. I even took it to the dealership and they wanted to replace the engine.

I just changed the plugs. They were worn out and it was obvious. I've had no problem in the last 2 days.

Now I am not sure if I should try the weep hole. I guess I will see if it happens again.

 

Fantastic! It definitely needed new plugs. That was probably the fix!

 

Sounds like your town has a bunch of incompetent shops - replacing coils without even looking at the plugs, and a DEALER that wants to replace the engine?

I'll say it again - replace Ecoboost plugs every 40k!

 

Seems to me that any air that would be escaping from that weep hole would not be accounted for in the fuel managagement. I'm assuming the ecoboost engine has a mass air flow sensor. The maf measures the air that enters the engine and any that escapes through the weep hole is unaccounted for. Maybe I'm incorrect. But that would be my worry with drilling a hole in the cooler. Ford has not recommended the hole being drilled from what I understand.