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As usual, I've searched but couldn't find anything that matched this scenario. I have an Excursion with 220k miles. I've owned the truck for 6+ years and had very few problems. I change my own oil and fuel filters, but beyond that I know next to nothing about the diesel motor. I do run a DP Tuner with the standard 80 hp program. And a 4" exhaust. Everything else is stock. I do keep it plugged it for the oil heater and the battery tender just about all the time now.
This latest issue started yesterday morning when my wife jumped in a cool truck to take the kids to the dentist (not warmed up but still 55 degrees ambient). A few miles down the road (35 mph max) the motor began stumbling and rocking and black smoke coming from the exhaust with reduced power. She pulled off and kept it running (very rough and rocking) and put it in park for a minute. When she put back in drive, it shifted heavily but the power was normal so she went on her way without any problems. The only report I got sounded like the motor was just cold and rough, so I thought nothing more of it.
Yesterday evening we drove it about 70 miles on the highway (72 mph max) with no issue at all, but when we continued on surface streets toward our destination (50 mph max) it did the same thing, but would not settle back down. I kid you not that it went through gallons of fuel the last 12 miles or so, just dumping black smoke out the exhaust. It felt to me like we were running 1/2 the motor, like the plugs weren't lit. Very rough and rocking and very little power (comparatively, at least). I had to switch to manually shifting the trans to get going and the shifts were much rougher than usual. Idle was low and rough but it never stalled. Felt sorry for the folks behind me since there was a huge smoke screen this entire time.
We made it to our destination and parked it. Did our thing and after 5 hours went out with finger crossed. Started right up and ran perfectly the entire 91 miles home. No motor or trans issues at all. Currently running 10/40 synthetic oil that I just changed about 2000 miles ago. Oil level is perfect. 3/4 tank of fuel with standard level of Diesel Kleen added. Fuel filter is less than 10k miles old. Temps yesterday were 65-70 on the drive down and 50-55 on the way back.
Any ideas? I jiggled all sorts of connectors this morning and didn't find anything loose.
It could be a UVHC issue, there are plenty of write ups on the correct procedure for checking these, you may want to search out the "50 cent mod" too while your at it. A loose connection can cause you to loose some or all of your cylinders on that bank, the connection could be intermittently dropping out, which would in part explain your symptoms. Just for a point of reference, your plugs do not stay active the whole time the engine is running. They are just used on cold starts and for a max duration of about 2 minutes.
Check fuel pressure, assuming you have the adapter.
I would also take the intake ducting off, and get a look ( and a hand) on the turbo wheel (engine off of course) to check for dusting and/or play.
You really need to get a scanner on it also, to check for codes, and do an injector buzz test and a cylinder contribution test.I would also suggest doing an ohm check on the injector wiring, from the IDM all the way through the 42-pin connector, and the UVCH to the injectors.
Keep in mind, you are also at the mileage when injectors commonly start failing.
I figured it had to do with the UVHC but couldn't figure out why it would be intermittent like that. I took it out again today for about 14 miles round-trip with 2 hours between and had no issues.
Looking at what's involved I think I need to take this to get it worked on so I want to get everything I should get done at once. Truck won't fit in my garage and this isn't the time of year to leave it open for days or weeks. What else should I get done since it's going to get opened? Injectors I guess (stock or otherwise?). Glow plugs?
Lots of soot? Can't rule out the Injector Control Pressure sensor (ICP sensor). After checking the UVCH and if it check out OK, pull the ICP sensor connector if you get a re-occurrence and see if that helps. You will get a warning light on the dash when you do this, but it is standard troubleshooting procedure by the book.
Thanks for that info. The smoke was absolutely black.
Closest person on your BEST list is 90 miles away. And the schematic would be great if I could work on it myself, but alas I cannot here. I'll ask around, but won't hold my breath finding someone local. Even the shops around here don't have diesel mechanics - except for the dealer, of course.
Forgot to mention that when it happened, both times, the CEL never lit up. Odd I think.
I thought blue smoke was oil on diesels and black smoke was incompletely burned fuel and white was raw fuel (unless it smells sweet or like coolant, if that's the case you have a coolant leak issue)
Yeah, it was definitely unburned fuel. The whole truck was rocking severely because only half of the motor was working. Have run the truck a few more times without any trouble, which is maddening. But in March I'll need it to be fully functioning so I've got to get it worked on.
Which brings up the question I asked earlier: what else should I get replaced while they have it open? Glow plugs even if it's early? The glow plug controller units? Injectors (stock or aftermarket)? I think I'll keep it for another 5 years/70-80k miles so I want it to be done right.
Glow plugs for sure, and make sure they/you use only the motorcraft brand of these, the aftermarket (autolite and such) can have major problems after a period of time. There is only a dollar or two difference between the two, so well worth the extra in this case.
As for the controller, I am presuming you mean the GPR? If so then they/you can check it to make sure it is working properly, but the GPR is readily accessible without removing any engine components of it were to fail later on.
As far as injectors, that is all going to depend on what you use the truck for and how much (if any) extra power you feel you may want. Once you decide on what type of injector (you will need to get a tuner/chip if you decide on the single shot variety as opposed to the split shots that come stock) then you have to decide if you want to spring for new ones or remans. There is a few threads on this subject if you use the search option.
I actually have the control module instead of the relays on mine. I'm guessing I don't need to replace that at this point.
So yours is a California model, or an Excursion? Even so you should still be able access the module easily. I believe if there were any issues with the module it should set a CEL. If it is working correctly at this point I believe I would leave it alone if it were me.
One other thing I would suggest is torquing the injectors to 120 INCH pounds, if you don't change them. They can work a little loose after a while. They should be torqued with the engine at operating temp.
Found a good place to get the truck worked on. They ran the buzz tests and all sorts of other diags and found no problems anywhere. Sad but true. But the good news is that all of the injectors test well and look good so didn't need to replace those. New harnesses installed and they're also replacing the ICP.
Continuing the long tradition of this truck eating batteries, they tested my 3-yr old battery after the truck had a hard start yesterday (it was 17 degrees and they didn't have it plugged in, so no surprise) and said it was not putting out any contributing amps. Note that I had tested this battery one week before and found 12.7v while the other battery was only at 12.0 so I replaced the dead battery at 4.5 years. Now I'll have two new batteries for the first time and hooked to the battery tender the whole time. I hope to keep these for several years.
12-30-2015, 10:42 AM
Intermittent rough motor, black smoke, low power
