My truck starts just fine, but lately, as I get up to speed (around 40 mph) the "Service Engine Soon" light comes on and the truck begins to shudder and shake like driving on a bumpy road. I can tell that the truck immediately loses power also. Sometimes the light will go off after 30 seconds and the truck drives fine and I won't see the problem again for the remainder of the driving cycle. Sometimes the light stays on and the truck runs rough the entire time. Other times, the light will come on, go off, come on, go off, etc. I bought a code scanner and it gave me a "No Codes" reading. I just changed the fuel filter and air filter last week thinking that may be the problem, but it still happens. Has anyone had a similar experience? Any help would be greatly appreciated. Thanks.
2001 F350, 7.3 L Turbo Diesel, Crew Cab
Welcome to FTE Darren. Most of the generic (read inexpensive) code readers will not work on our engines. I'd be willing to guess if you could read the code that is in there it would be a P1316 code. The common cause for what you're describing is a loose plug on the UVCH (under valve cover harness)
Here's what the problem looks like
Now the trick is to figure out which valve cover you need to remove to plug this thing back in. Since you don't have a good scanner that can run things like a buzz test, the next best option is to grab a multi-meter and set it to read ohms. Located on the inboard side of each valve cover you will see some wires leading to a plug connector. This is a flat 9 pin connector that you will need to unplug to expose the pins inside.
The 9-pin plug is wired as follows:
G G I I C I I G G
G=Glow Plug +
I = Injector +
C= Injector Common
The injectors fire with a 115VDC signal from the IDM. Do Not pierce the wires to test.
Test between "I" and "C" to test the injectors, should be less than 5.0 Ohms.
To check glow plugs Test between "G" and battery ground. Should be between 0.6 and 2.0 Ohms
If you find readings outside these numbers, pull that valve cover and check for the loose connector.
We also have a 7.3 diesel specific section located a little further down the main forum listing page. We'll see if we can't get your thread moved down there so you get more input on this from other folks that have the same motor.
I agree with Rick and Chris.. it is your under valve cover plastic piece of junk 9 pin connector is coming loose.. I made a shim to slip behind the the two plastic locking tabs of the connector to prevent it from happening again.. ... or you can buy a repair clip from Ford.. Let us know what you find.. (the covers gaskets are reusable)..
Passenger side test between "G" and battery ground: (also what the ??)
I double checked my multimeter settings and checked each connector twice. From these results, it appears that the passenger side UVCH may be totally loose and the driver's side UVCH is working it's way loose. I drove the truck today and the SES light came on immediately and stayed on the entire driving cycle. The truck had no power at all and shook like crazy. I'm looking to the experts for advice on what I should do next. Is it common for the UVCH on both sides of the engine to come loose?
Sounds like you're on the right track Darren. Remember the other possibility for some of your readings may be you have some bad glow plugs. This won't affect how the truck is running, but as long as your pulling valve covers, might as well replace any bad ones. Have you had any trouble or excessive smoking starting in cold weather?
To address the issue of the loose plugs, there is a retainer clip you can purchase from Ford or International to prevent this from happening again. The other option would be to make yourself a shim to prevent the plug from coming loose. A quarter just happens to be the right width and thickness if you grind one edge down. That's what I used on my truck.
The other thing I would suggest you do while you have the valve covers off is to re-torque the rocker arm pedestal bolts (circled in Red) to 20 ft-lbs, and the lower injector hold down bolts (circled in Blue) to 120 in-lbs. They've been known to work their way a little loose, and tightening 1/4 to 1/2 turn on any loose injectors really makes your engine sound better.
If you have any questions, don't be shy about asking.
Chris, I just started pulling the driver's side valve cover off about 30 minutes ago. There is alot of stuff in the way, i'm guessing it's the intercooler duct which i removed. However, there is a small black duct about a foot long that connects to where you see the turbine in the turbocharger and there is a small (1 inch diameter or so) hose in the bottom of that duct that runs to some small metal box on top of the valve cover. It seems like i need to get that duct out of the way to get to my valve cover, is that true? How do you get it off? It looks like some sort of clamp i've never seen before. The passenger side looks like its going to be even worse, but if i can get the driver's side off tonight, i will consider it a small victory. Thanks for your help.
What you're describing is the crank case vent (CCV). It's got a metal band that holds that little hose on to the doghouse (funny box on the valve cover) and the part of the intake tube. Take a pair of pliers and twist that band clamp to get that little 90 deg hose off. A regular hose clamp can go back in it's place when you put things back together.
Don't get discouraged. The hardest part of this whole job is just getting the stuff out of the way so you can remove the valve covers. Personally, I think the passenger side is the easier one, but I've only seen one other member here agree with me on that. The worst bolt on the drivers side will be the one in the back of the valve cover. You'll just need a 3" extension with a short socket and remove it by feel, since there's no way to see it.
On the passenger side, I use a swivel adapter to get the 2 bolts next to the AC. Others use a wrench and access the bolts from under the wheel well. The plastic clips that hold the heater hoses just slide off the bolts (sometimes it takes a little convincing). It's also easier if you unscrew the oil fill tube and take it off the valve cover before pulling it. Getting the passenger valve cover out of the engine bay on an auto tranny takes holding your tongue just right.
Don't worry too much. You'll get the drivers cover off tonight.
Ok, I got the CCV hose off and the black duct out of the way. After that, it was easy to get the valve cover off, and guess what?? The UVCH was extremely loose; i could easily push it further into the connector about 1/4 inch, so I think this is definitely the problem on the driver's side. I'm very happy!! I suspect that the passenger side will be the same story. What are the specific steps i should take to get the passenger side valve cover off? Anything I need to be aware of?
Also, in working around the turbocharger and intercooler ducts during this project, i noticed that they have sort of a film or grease/dirt on them. Is that normal? I spun the turbine in the turbocharger by hand and there didn't appear to be any binding, so I think it's ok. I'm just wondering how the grease got on the outside of the intercooler ducts.
So would you recommend the quarter trick or actually buying the shim from the dealer? How much does the dealer part cost? Have you had any problems with your quarter method?
Last thing, you mentioned bad glow plugs earlier. How do I tell if the glow plugs are bad? Should i just replace all of them while i'm in there? Any specific brand that you recommend?
Thanks again for providing such great advice. I will be leaving for College Station tomorrow, but will be back Sunday to attempt the passenger side. I hope you'll be around in case i have any questions.
Where are you leaving from to head to College Station. Sounds like you're another Texas boy. I live 15 miles North of Hillsboro. Don't suppose you're near me are you?
Now that you have the plug connected properly, go ahead and ohm the glow plugs again. If you still get bad readings, go ahead and change those plugs, just don't use autolites as replacements.
I don't know how much the Ford shims cost, but my shims cost 25 cents each. While the valve cover is off, go ahead and grab a quarter (no need to grind it down yet) and slide it in the connector. You'll see how snug it fits. If you grind the top down so it fits inside the valve cover, you'll see there's nowhere for the quarter to go once it's installed and the valve cover is put back on. I've done this to my truck, my wife's, a couple of work trucks, and a fellow member here at FTE (millerfeed) and haven't seen any problems.
If you want to check your turbo, grab the shaft in the middle of the wheel and wiggle it around. You should feel a slight up and down or side to side play as long as it doesn't touch the housing. You should not feel any in and out play on the shaft.
I should be around, but not to worry. You're in good hands here at FTE, and we're a lot less expensive than the dealer.
That CCV hose and clamp contribute to that oily film all over the place! Lots of us have done the CCV mod by plugging the outlet into the air intake, turning the "doghouse" around and routing tubing to the back of the truck. Do a search to get a better idea and pics, and once you do it you can keep the engine lookin cleaner.
I would go for the quarter trick. Its only a quarter and u dont have to leave the house! Never seen it before but if Chris did it, chances are its a good, easy fix.
You can ohm your GPs out to see if theyre good or not. More than 2 or so ohms and theyre most likely bad. DONT BUY AUTOLITES!!!