Ok, here we go, 2004 Ford Escape, 6 cyl, about 152000 miles. I have had a reoccurring issue with this car misfiring after or during wet weather. When misfiring, the check engine light is flashing. After a day or so of dry weather the problem goes away.

The first time this occurred was after my #3 cylinder blew out a spark plug and damaged the ignition coil pack at that cylinder. Initially I changed the coil pack and spark plug and moved on. The next time it rained I had the problem with the check engine light flashing. I checked all the plugs and coil pack connections, the car sat for a few days then seemed to run fine.

After I first read about these issues, I understand there could be a short in the ignition system that will eventually lead to PCU failure.

I changed all the coil packs (using motorcraft parts) and spark plugs (oem motorcraft), hoping to stop the issue. Everything seemed fine, but now it is happening again.

Any suggestions?

It does not look like Ford has a clear solution and I may be heading towards changing the PCU, wiring harness, coil packs (again), and spark plugs.

 

if your getting a check engine light now try just swapping the one in the cylinder that's misfiring with a good cylinder and see if the CEL will indicate the other cylinder. I assume when you replaced the coils you got new boots with them. did you clean off the hole the boot attaches to with a solvent? dirt and moisture are an enemy of high voltage. It's definitely a hi voltage misfire problem if it's only doing it in wet weather. something from the high voltage connection inside the spark plug hole is going to ground caused by damp weather. You can buy just the boots for the coils for a few dollars each, they come with a new spring too. Don't replace the PCU, it's not the problem and it would be a waste of money.

 

the new coils came with boots and springs. before I replaced all the coils, I had replaced only one previously. I did a few scans back then and the codes would be for either the 3 or 5 cyl. I tried swapping coil places and 3 and/or 5 kept coming up, neither at the same time though.

I use to be able to borrow a scan tool from autozone, but thanks to Lobbiests, Ca passed a law saying they cant lend these out anymore. Guess too many mechanics were complaining they were missing out on diagnos money. Im in search of someone local that will scan this time for free.

 

also, I tried to find the source of the short by misting the engine compartment looking for arcing. No luck. this is really perplexing to me.

Has anyone dealt with Ford regarding this. It seems to be wide spread, I read one account where it sounded like ford at a TSB regarding this and reportedly even covered repair costs. I called a dealership today and fords customer care 1800 number and neither could find any TSB's or reported issues similar to mine. Hard to believe with all Ive researched.

 

There's a TSB for maybe '05 or '06 on a certain OEM spark plug burning up coils and possible coil drivers in the PCM. Earlier Escape don't handle multiple misfires well as it doesn't shut the injectors off which will cause a destroyed CAT(s).

 

Heres a little update, cleaned the front most accessible connections, disconnected the battery for a few minutes. The check engine light is off and it is still misfiring at cruising speeds.

I am torn between getting rid of the car or going through with the repair. Within the last 5K miles I had replaced all the COPs (oem) and spark plugs with OEM motorcraft spark plugs. THerefore, I dont think replacing these parts again will be the quick fix, something more sinister seems to be happening.

I am wondering if I should have used an aftermarket Autolite spark plug since I hear the short could be attributed to the stock spark plugs? Thoughts.

I found a ford dealer on ebay selling the newer PCM 5L8Z-12A650-LH for around $700. I know I will need to have ford reprogram the PCM for the keys to work.

Does anyone think investing $700 in a PCM, $20 in new plugs, and new COP's set of 6 aftermarket for 80 or motorcraft 6 for $600. Figuring Fords time would be about $200 and about $225 for me to tow to nearest ford dealer, Id be looking at between 1225 to 1745 in cost for me to do the work.

The big questing is of course using the aftermarket COP? thoughts, when I replaced them previously the seller guaranteed I was getting motorcraft COP, these were bought 6 for $120, I can try to contact them again, but Im a little suspect by their motorcraft claim for so cheap.

Id hate to invest nearly $2K and still be sitting where I am today. Also, I have a little concern that maybe there is a short in the wiring harness, it does not seem easy to find a replacement harness so I try not to think about this.

 

Did you replace the lower and upper intake gaskets? You could have a vacuum leak.I had 2 coil packs fail the first one didn,t throw on the cel but there was a code pending.Scanners can be bought for $50 up its a handy thing to have.

 

How about just taking it to someone with the knowledge and tools to properly diagnose it? Why are you talking about replacing the PCM and wiring harness? Unless the harness is damaged by fire, it can easily be repaired. Why make this more difficult than it is? Mechanics repair tens of thousands of vehicles on a daily basis. Some just like yours.

You keep focusing in on the ignition system. Could very well be a valve sticking, clogged or sticking injector, or simple chafed wire, which isn't uncommon.

 

If you replaced the COPs with new, and they actually were OEM Motorcraft parts, it is unlikely that they have failed so soon. Possible, but not likely.
If it were mine, I would be checking the harness from the COP to the PCM. The computer provides a ground signal, and then removes it to cause the coil to fire. If the insulation is chafed, or the wires breaking internally from flexing too often, you can get misfire. If the water penetrates the connections or the insulation, and forms a path to ground, the coil(s) will never build a field, never produce voltage. It is NOT definitely a high voltage problem. {it may be a lack of high voltage problem}
A scan tool may be helpful, but the Mk I mod 0 eyeball is readily available, and can inspect the wiring for problems. It can also inspect the engine ground wire connections and the underhood connections at the power distribution box and the large squarish connector that is near the battery box. It could be corroded, leading to poor connections.
tom

 

Although this post comes over a year later, I wanted to share my experience with my 2004 Ford Escape. My Escape has been extremely reliable and dependable with 105K on it. About 6 months ago it sat outside in a heavy, rain, wind storm while I was at work. When I started the car after sitting for 9 hours, the car misfired miserably. After warming the car up and driving it home, it straightened itself out. There never was a problem until last week when I took the vehicle for a 200 mile trip to our vacation resort. The "check engine" light began to flicker and I could feel the car misfiring and skipping. I reluctantly made an appointment with the Ford Dealer that was out of state and I was unfamiliar with any of the staff. They took the vehicle in and diagnosed two codes that were causing the havoc. P0304 and P0316. They changed the plug and coil on the number four cylinder and assured me I was all set. After paying my $350.02 bill, I felt relieved that the problem was cured despite the non-budgeted expense while on vacation. I drove the vehicle back to our place and it sat for most of that day.

The following day we had plans and jumped in the Escape. Upon starting, the same, exact thing happened. The check engine light started flickering and the vehicle was misfiring. I was not happy. It was the fourth of July and no dealer in the USA is open on the fourth of July. I called the following day and the service writer was disappointed to hear I was inconvenienced and squeezed me back in, realizing I needed the car to get home. This time the codes P0305 and P0316 revealed the number five cylinder plug and coil needed replacing. I was completely at their mercy and had them complete this second job in less than two days. The dealership felt bad about the entire situation and discounted this job 100 dollars less than the last one. I was still not confident that the vehicle would make it home without more havoc.

The service department advised me that there is a TSB on PCM with Ford Escapes Ignition Coils and Plugs. So beware! Why Ford didn't recall the vehicle seeing this is a known issue is beyond me but I'm sure I'm not the only experiencing problems similar to this. I plan on writing a letter to Ford after buying Fords exclusively for 45 years. I'm sure they won't reimburse me for any costs but I am going to let them know my experience for whatever it's worth. The service writer advised me to keep my fingers crossed because once this cycle begins, usually the brain of the car will go and that's extremely expensive (not encouraging news)

Anyway, I wanted to share this with all the Ford Escape owners who have coil and plug problems. Again, this problem is a known issue with a TSB on PCM, Ignition coils and plugs.

By the way, the vehicle made the 200 mile ride home without incident. I am hoping that this is the last of it for a while but I don't think so. Although I don't plan on sinking $350.00 into a 10 year old car every time a coil blows, and they seem to be blowing regularly, I will give this car a lot of latitude. It owes me nothing and I hate to part with it.

Peace,

Glenn

 

Am wondering how your problem with the Escape worked out. What did you find?

 

Did they replace your upper and lower intake manifold gaskets?Did they replace all the spark plugs?

 

MrGC, had you changed the spark plugs before your #4 & #5 failures? Normal maintenance calls for their replacement at the 100k mile service.
Having read on the net of the COP and possible ECM failures, I changed my plugs a little early. The electrode gap was larger than specified. That would cause the plug to have to build to a higher voltage before the spark would jump the gap. Rounded electrodes due to wear also make the spark reluctant to jump, so the voltage again is higher. If it gets high enough, it can jump through the COP boot to the cylinder head. That causes the misfire code, and can allow unburned fuel into the catalytic converter, which will melt the gizzards. Not good, and expensive to repair.
If you haven't changed the remaining 4 plugs, do so at your earliest opportunity.

tom

 

BMuhl - I did not replace any manifold gaskets at this time.

 

Tom - thanks for your reply!
What you are saying makes sense. I need to change the other four plugs asap.
Funny thing was my hometown Ford Dealer recommended the plugs and boots being changed when I got back from vacation for approx $460.00. I told him I would make an appointment. Possibly, this would have not happened if I did it before I left. I guess at 105K I should also consider changing the timing belt?
I plan on keeping the car but at the same time, I don't want to go broke preserving it. When does it all end?
Thanks everyone for all the great advice.