Spent the weekend working on the E-350. At least the Old Girl had the decency to act-up on a Saturday morning at home, and even tho it’s December, it was sunny skies and high 50° all weekend.
Symptoms: substantial loss of power, “Service Engine Soon” dash light, rough idle, throwing P1316 DTC (Injector Driver Module).
Since I don’t have a fancy scanner with the “buzz test”, first thing I did was put an IR temperature gun on the exhaust manifolds. Driver side was reading 215° down the line, while the passenger was 85°. So, right away I’m thinking harness problem, since the chances all four injectors failing at the same time is nearly impossible.
Also, some quick google-fu turned up this excellent video on the subject. This guy is a great resource. https://youtu.be/GHwjEfJtM_g
Looks like a textbook valve cover wiring harness failure.
Like just about everything on the E-350, getting at the problem is a big problem. The engine bay is so tightly packed, disassembling stuff that’s in the way is always required. Getting access to the passenger valve cover, I removed: interior engine cover, heat shield, resonator box supports, air intake assembly, serpentine belt, top alternator, passenger wheel, and oil dipstick tube.
So, with all that stuff out of the way, getting access to the ten valve cover bolts went from impossible to very difficult. Little did I know, the valve cover bolts were the easy part compared to the under cover wiring harness connections.
Anyway, spent a leisurely four hours disassembling on Saturday. I checked the glow plug relay since it was also accessible, and discovered it was bad, as well. Checking is as easy as turning the ignition forward for the “Wait to Start” light, then a voltmeter on the feed lug confirmed the plugs weren’t getting any power. This would also explain why starting the van under 50° was nearly impossible without having the engine block heater plugged in.
So, once I got the gasket out, it was obvious. The under valve wiring harness connector had slipped right off the gasket plug. What happens is the little plastic tab that keeps it positively locked fatigues and the vibration works it off. I decided not to do the “DieselTechRon” 25¢ fix (as seen in video link, above). The way the connector clips are designed, I wasn’t confident the quarter itself wouldn’t eventually work its way out, too. Went with an aftermarket from AutoZone that has the under valve cover wire harness integrated into the gasket- no connector to slip loose.
I’m sure I’ll be doing the driver side bank in the near future, and I’ll be getting a pair of these to get the glow plug clips connected. It’s nearly impossible to see the tops of the glow plugs since they’re sitting down in the head; and because you’re reaching into such a tight space, there’s no way to actually see what you’re doing. Had to make connections by feel.
$145 and about seven hours later, the Econosaurus™ is running like a top.
See You Down the Road!