Heater hose fail, now misfiring like crazy

[Matthew Goulart]

Hi all,

Hoping someone can help.

07 5.4 Expy here. Wife had a hose fail on the freeway, the heater hose off the firewall that doesn't have a "Y" in it, (I think its the one on the right) deteriorated inside the metal jacket portion and blew coolant all over the engine / trans / exhaust. Those quick disconnects at the firewall are a ***** to get off, so I paid the shop 240.00 to replace a 6" portion and fill it back up with coolant.

But when we picked it up, it ran horrible. They fixed the hose, but the idle is rough, and it bucks on acceleration, its not safe to drive.. I've had misfires before, so I replaced all 8 plugs with motorcraft, checked the ohms resistance on the CP's, (all fine). Cleaned all electrical connections. Still ran like shit.
So I checked the MAF, fine.. Checked the throttle body, fine..

So now I'm scratching my head.. I have a scanner but it isn't throwing a CE yet because I unhooked the battery. Thinking of driving tomorrow as much as I hate beating the engine up.

Thanks in advance!
Matt

 

[Adieu]

That's a classic

Your leak or your mechanic got coolant into one or more spark plug wells.

That screws up the ignition coil on that cylinder, and for some reason may also screw up the corresponding injector (not sure if it's from coolant contact or running it with a damaged coil/plug set on that cylinder, somehow... just that it happens)

If it's ongoing, your jury-rigged replacement (motorcraft hose costs like 45 bucks fyi) may be leaking or one or more iniectors are done (not as scary as it sounds, injectors are $25-35ish ea, replaceable in 5 minutes, and it's probably only 1 or 2)... or 1 or 2 coils are done, despite testing OK for resistance. Generic coil sets are $30 - 60 on Amazon for all 8, just make sure you get the right ones.

Likely victim : cylinder #2, passenger side second closest to front of vehicle

 

[Adieu]

If I were you, I'd order Amazon's cheap Chinese coils and 1 injector (when I needed it, Walmart,com was cheapest/fastest for some reason)... swap in coils, if that doesn't help, swap the new injector through cylinders 2 3 1 and 4 in that order, probably

Cheaper and easier to do it in one go and be done in an hour or two, with the $60 - 95 in parts on hand.

Oh and not sure what kind of scanner you got, but if you don't have it yet, spend the $12 and get a decent ELM327 bluetooth dongle if you have an android phone or tablet. "Panlong" brand on Amazon is a keeper that lasts for years.

 

[Trainmaster]

Adieu's right as always. The coils are firing, but their spark is tracking to ground. But they'll check out fine. And you should change a couple of the rubber boots on the coils too. They may be leaking current also.

And what's with replacing a "6" portion of hose"? If six inches of it were bad, don't you think the rest is about to give way too?

How many miles on this truck?

 

[Adieu]

Adieu's right as always. The coils are firing, but their spark is tracking to ground. But they'll check out fine. And you should change a couple of the rubber boots on the coils too. They may be leaking current also.

And what's with replacing a "6" portion of hose"? If six inches of it were bad, don't you think the rest is about to give way too?

How many miles on this truck?

It's the disheartening 5-10 minutes of stretching and cursing and trying again and again that often accompanies disconnecting a Ford quickconnect

Well, they never said it was quickDISconnect...

 

[jeff kushner]

Sounds off the top, like you overheated and ruptured the headgasket. A compression test will confirm. The plugs can fire all day but if there is no compression....the result will be a misfire.

Just a guess though...

good luck,

jeff

 

[Adieu]

Sounds off the top, like you overheated and ruptured the headgasket. A compression test will confirm. The plugs can fire all day but if there is no compression....the result will be a misfire.

Just a guess though...

good luck,

jeff

I hear about head gaskets so often I'm starting to suspect it's the new and improved blinker fluid --- peddled by dishonest shops whenever a customer comes in with a badly running motor, and seems to have expectations of a large repair bill...

The maybe-15-minutes it takes to swap in 30 bucks of ignition coils just doesn't excite most businesses

 

[Matthew Goulart]

Adieu, Trainmaster, and Jeff, I really appreciate all of your guys' feedback. I also appreciate Jeff's avatar. The hose was a 57.00 part from the dealer now that I look at the invoice.. (When I spoke to the service writer he showed me a portion of hose that appeared to only go from the firewall to a mid section of the hose, so I think I was wrong on my OP.

This morning, I put the last CP back on and rechecked all connections. Low and behold it fired up and idled fine. Took it for a test drive til it was to temp and it appears to now be running much, much better. I told the wife not to beat the crap out of it today and report back. I'm thinking (possibly) the second time I removed, cleaned and reinstalled and connected the CP's may have helped?

I think I'm going to go ahead and replace all the injectors for good measure on the right side, and then the other 4 next payday. The Expedition has about 130K on it and they're still stock injectors.

Would you guys recommend nothing but Motorcraft on the injectors? Sounds like you're saying I could go a different brand and be okay?

Thanks again, I didn't expect to get such a fast response here.

 

[Trainmaster]

No need to change the injectors. They last and last and last. But coils do fail and plug boots break down.

When the thing dries out check it for a miss and go after the cylinder's coil and boot that have the miss. Only if that doesn't work should you even think of injectors.

 

[Adieu]

Adieu, Trainmaster, and Jeff, I really appreciate all of your guys' feedback. I also appreciate Jeff's avatar. The hose was a 57.00 part from the dealer now that I look at the invoice.. (When I spoke to the service writer he showed me a portion of hose that appeared to only go from the firewall to a mid section of the hose, so I think I was wrong on my OP.

This morning, I put the last CP back on and rechecked all connections. Low and behold it fired up and idled fine. Took it for a test drive til it was to temp and it appears to now be running much, much better. I told the wife not to beat the crap out of it today and report back. I'm thinking (possibly) the second time I removed, cleaned and reinstalled and connected the CP's may have helped?

I think I'm going to go ahead and replace all the injectors for good measure on the right side, and then the other 4 next payday. The Expedition has about 130K on it and they're still stock injectors.

Would you guys recommend nothing but Motorcraft on the injectors? Sounds like you're saying I could go a different brand and be okay?

Thanks again, I didn't expect to get such a fast response here.

Ain't no such thing as a Motorcraft-made injector... they're rebranded from one of several suppliers, Bosch and some other companies iirc.

What you probably need is COPs (aka "coils" aka "ignition coils"), not a full set of injectors.