Hi all,
I'm experiencing yet another problem with my Excursion that I need to fix. This is similar to but not identical to previous problems that I've spent a lot of time and money fixing so I'm hoping someone can see what's gone wrong. The problem started at Christmas (yeah, I know) with half the motor shutting down randomly when driving around town. We believe it's always the passenger side. Get on the highway and it purrs along with no problems. But around town, boom, it just loses half the motor, comes back to all 8 cylinders, then down to 4 throughout any trip. We took off the valve covers and examined the gasket wiring (we've replaced those a few times over the last 5 years) and found nothing.

At some point in January we started to notice some oil or diesel spewing out the passenger side of the engine when running on half. Shortly after that it stopped running at all. It starts on 4 cylinders, then after 5 seconds it stalls out. Again we looked at the passenger side to see if something was loose or disconnected but found nothing.

In the past few years I've taken it in to get a new IDM and a new hydroboost. That's on top of new valve cover gaskets and glow plugs. Currently has 279k miles on it.

Please give me some ideas on what to check. I'll be looking for the source of the leak on the pass side this morning since fresh stuff appeared after I started it a few times. I'll share that info in an hour or two.

 

I forgot to mention that I ran ForSkin and TorquePro this morning and got P1209, P1210, P1211, P1316, and P0603 faults. There was also a B2103 PATS fault that I don't recall seeing before.

 

Are there any CEL or codes showing up? Has the hutch mod been done on the truck yet? Are you sure the leak is in fact oil? Diesel fuel passing through some old engine grime on it's way to the ground can look a lot like oil. Have you inspected the steel lines that feed the cylinder heads from the fuel bowl? The passenger side line is a known leaker.

 

One more update - I traced the leak on the passenger side and, bizarrely, it's coming from the trans fluid tube. I'm completely baffled at this since I haven't messed with the trans fluid in years. Maybe all the shaking from running on half the engine shook the tube connection loose. But as far as I can tell, it's unrelated to the engine problem.

 

That sounds like your passenger under valve cover harness is coming loose . Did you say you had those replaced? If so do you know which brand?
On edit : just saw you replaced those a couple of times, did you use the dorman or motorcraft uvch?

 

Nothing was loose as I had thought (hoped) at the time. They were no name replacements from Amazon. So step one is to acquire some good Motorcraft replacements...

 

Anything electrical, sensors etc. It's best to use genuine motorcraft parts from a reputable distributor for these trucks. I'm not saying this is definitely your problem but I wouldn't rely on a no name Amazon part, especially for a uvch.

 

The P12xx codes are all hpo related. The 1209 is a high injection pressure code the other 2 are pretty generic. The P1316 means there are codes on the IDM that can be retrieved by running a buzz test. P0603 usually shows up after a power loss. Now the B2103 is for the PATS transceiver and I see several no start threads when searching it. I would run the buzz to get any codes there then clear them all. Try a few starts to trigger any current codes then scan again.

 

I wouldn’t trust a motorcraft Amazon part either, as you alluded to.

Maybe something shorting out in the wire harness causing the IDM to shut down a bank?

You could check the exhaust manifold temp to confirm which side is the culprit.

 

I just found that these were the Dorman UVCH gaskets, so not terrible, right? Only installed two years ago... I will check the connections on the harness.

I do have a new main harness to swap in to get rid of the short possibility. All of the other accessories/components have been updated in the last few years. Maybe try that swap tomorrow between storms.

 

Personally I've never been impressed with dorman nor had much luck w/any of their stuff. Actually swore a blood oath that they would never see a dime of my money ever again. Maybe a little extreme but ya leave a guy stranded because one of your parts breaks less than a month after the warranty is up he tends to get a little salty.

Have you run the buzz to get those IDM codes yet, or cleared all of them to see what comes back? Done any continuity testing between the 42 pin and valve covers or back to IDM yet also check continuity to ground for a short there. How's the 42 pin where it crossed the valve cover, no rubbing>

 

Dorman is better than just a random no name uvch on Amazon . These are all one piece so there's no plug underneath the valve cover like the motorcraft ones. Like udsuth said Hook up forscan and run a buzz test. Listen for a consistent buzz on each injector. You can also ohm out the wires from UVCH plug to the IDM. Being that I think you said this has been intermittent problem It may be a little tricky to track down. Best to diagnose when the problem is active.
On edit: just saw that udsuth already recommended this lol

 

Seems like folks have been seeing Dorman UVCHs fail quickly with the wire insulation becoming brittle.

 

Ford and Dorman have a contract.
Once the 10 years is up, Ford signs over the blueprints and patents to Dorman, this allows Dorman to create from Scratch, to the same precision as the OEM stuff.

the UVCH / gasket is one such improvement.
by molding the harness into the gasket itself, they took away the chance of the wires getting pinched under a bolt.

there is a lot of the old Dorman stuff on the shelves though, that was made prior to Dorman owning the patent rights.

the OEM steel wheels is one such item that Dorman now owns the rights to.
I have bought 8 steel rims for my Excursion,
4 with AT tires, black wheels
4 with Michelin street treads. gray wheels, why? dunno

they are identical in every regard to the original OEM wheels.
why did I buy new wheels? the ones on the truck were Bent @#$%



those ugly steps are gone now, I installed ARM Research hide away steps.


Hide away steps, no more broken hips

 

They may be “allowed” to build same as OEM, but I have yet to see a Dorman part that even comes close to OEM build quality.

Don’t get me wrong. I’m actually very thankful that Dorman fills a void in the parts market for our older vehicles. But I’d never expect it to last even half as long as the original.

I won’t be surprised if the “new” Dorman gaskets are the root cause of the OP’s issues.