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manderson2228 · 06-14-2018, 02:58 PM

Quote:

Originally Posted by TeJay

Mike,

It has been stated on these forums by several informed posters the V-10 is limited/governed to 75 MPH.

I did not read the entire first part of this thread but do recognize the CEL will only come on when a malfunction effects the emissions parameters. If you are setting a CEL and CODE then there has to be some data on the data stream that a qualified technician should be able to read to get a handle on what is setting the CODE.

Based on your comments and experience I'm sure you recognize what the system is supposed to do. I guess the kicker is "A qualified Technician."

I realize I've been out of the business for 12 years but it is my understanding once a CODE is set it remains unless the conditions which caused it don't again occur for "X" number of cool down and re-starts.

For the less informed readers. The CEL and subsequent CODE was never intended/meant to tell a technician exactly which part to replace. It only directed them down a path in a more probable fault direction. It is still a requirement to use their brain to make a diagnosis.

If one sees black soot in the tail pipe that usually means a RICH air fuel mixture. When running a proper stociometric (14.7 : 1) air fuel ratio the tail pipe will usually show a gray soot.

The code we are getting is P0300 random cylinder misfire. It has happened below 75 too so it can't be just that. They said they looked through the mode 6 data and could not find anything to point them in any direction. I've had it in 5 or 6 times now and nothing is getting solved at 2 different dealers.

TeJay · 06-14-2018, 07:04 PM

A P0300 random misfire code is pointing to something. I realize your unit is a 2018 with few miles. When confronted with these circumstances we don't want to go down that path. We don't want to condemn things like brand new Spark plugs, COP (Coil Over Plug) ignition coils. I'd guess the dealer does not want to go down that path either.

The code is telling something so it should be investigated. The absolute worst mistake any diagnostic technician can make is to assume a part is good because it's either a brand new replaced part or a brand new from the factory part.

What do they mean they can't duplicate it? The code was set. That means something happened for this wonderfully smart diagnostic system is telling them there's a random misfire.

We once parked out RV at home during Winter. Two months later we took it out and a misfire occurred going up the hill. A rodent chewed through a COP wiring harness.

Anything can be defective from the manufacturer or soon after it's put into service. To not say it can happen is not realistic. I'm sure glad Doctors who rely on symptoms and testing to point them in a direction don't make assumptions concerning my health.

Back in the mid 80's I began to loose my far vision so I went to see my family eye DR. After the exam he asked me if there was any diabetes in the family and I responded truthfully no. Following the blood test it was confirmed that I was at age 42 an insulin dependent diabetic. The first in our family on either side. That was 32 years ago and I'm still a diabetic.
Can you narrow down how or when the CEL comes on. Is it related to heat, cold, load or no load.

Since the parts are new it's not likely to be secondary insulation breakdown around the coils that is failing because of age. There may be an internal coil defect. If it's not the same coil then it may be something feeding a signal or voltage to the module that is controlling the delivery of the spark voltage. A technician is gong to have to think outside the box to solve this one and so far you have not found one.

THenne1713 · 06-14-2018, 11:38 PM

I am surprised that cracked COP connector gave a non-specific P0300 code versus identifying the cylinder; I think of a P0300 as probably more water in the fuel related for floating/ inconsistent miss; maybe even the floating miss that a radiator hose leak spraying on plugs might give as water pressure changed and leak spray moved around to different plugs?

TeJay · 06-15-2018, 09:30 AM

Most every poster is zeroing in on those items, coils, connectors, plugs, coolant spraying on high voltage items causing a short to ground, etc, etc. The dealers are not even wanting to investigate those items because they (again) are assuming if it's a new or new replacement part it CAN'T POSSIBLY BE DEFECTIVE.

I know what I'd do if it were my RV and nobody could figure out what to do. I already know where I'd take the RV. There are at least two techs in our area who will solve the problem because they can diagnose electrical issues and do think outside the box.

One tech does not work on RV's but he'll work on any vehicle. The other tech will work on RV's and knows how to follow, symptoms and diagnose. If Ford can't recommend a shop with qualified techs then I'd call Ford CS and tell them you found a shop that can maybe solve the problem. They can/should authorize you to take it there. That's what I did when we needed an alignment and no Ford garage within 100 miles had the equipment.

You've already taken it to two shops with no luck. Try a different approach.

The water spray idea is a good one. My thought is the anti-freeze should/might eventually leave a green or orange maybe white dry residue wherever it is spraying and then drying because of engine heat. Leaking coolant almost always did that for me.