mother of all problem children

Brad Clayton · March 13, 2011

This is a tale of woe. The tale I speak of can be described as a nightmare, a tragedy, or even a dark comedy. I personally consider it a nightmare. This fiasco is truly one of the reasons a diesel tech should be paid hourly instead of flat rate.

Things begin with a 2007 F-550 that starts hard when hot. This truck is a work horse and rarely gets a break. It has a dump body on it and is outfitted with a sander and a 10 foot plow during the winter. Everything that moves is operated by hydraulics and is driven by a PTO that is bolted to the engine beside the alternator and driven off the FEAD. The truck registers 60k and some change on the odometer and the hour clock runs it right over 100k as far as mileage is concerned. The customer originally came in complaining of a noise that they think is the frame mounted fuel pump and oil in the “turbo lines”. Well this seems simple enough, we just put a fuel pump and pressure regulator in it last week. A quick check reveals that the aftermarket PTO hydraulic hoses are rubbing on the heater box and vibrating horrifically and the cac system has normal oil carry over. The owner just replaced the clutch and hub on the PTO and must have moved something in the process to create the vibration. They were ok with that and decided to pick it up, but wait, “hey while you have it there, it starts hard sometimes”. And so it begins…..my long dark journey to extreme hair loss, sleepless nights, and the road to going broke.

If there is anyone to blame, then it is me. I am my worst own enemy. I am hesitant to ask for help, I know what I am doing, right? I take short cuts, draw conclusions without enough information and on and on. Now that that is out of the way onward we go. The truck has a ton of history and has had multiple high dollar repairs. To say that there are quite a few clues and hints to something amiss with this truck would be an understatement. Clue #1: the truck sounded “funny” and started “funny” the first time I got in it. I was actually glad they weren’t complaining about it at first.

I clocked in on the 3rd line on the repair order (long crank when hot) and got the truck up to about 190 degrees F. I monitored all the prevalent pids and nothing looked out of the ordinary. My main focus was to see what the IPR percentage was at hot idle. I shut the truck off and let it sit for 5 minutes and bingo, it took about 15 seconds to get it going again. Now for some odd reason, I decided not to look at the history in OASIS. I just dove in with both feet and pulled the HPOP cover to have a look at the STC fitting. Guess what? It had a brand new update in its place. Well, given all the bolts that were in the wrong place and missing, I decide to pull both valve covers to have a look at the rail plugs and injectors. Again, all these parts are brand new, dummy plugs, stand pipes, and injectors. Huh, some serious head scratchin’ going on now. To keep this from becoming a total loss, I decide to pull the HPOP and have a better look underneath it. When I get the pump out, plenty of oil runs out of the supply gallery so no problem there. I place the pump on my work bench and just barely touch the gear and it spins with ease. Most of the pumps I see require a wrench on the gear bolt to get the thing to turn. I could spin this gear with my pinkie while covering the input hole. Whilst this thing is apart I run into clue #2: the cac system has a lot more oil in it than I would normally expect to see. This heavy amount of oil vapor supports what the customer was complaining about.

So now I am happy and I order up a pump. The next day the pump shows up and I install it and reassemble the engine. I bleed the system and get it started, warm it up and shut it down. The moment of truth is upon me, and it truly lets me down. Wicked hard start would be an understatement. Frustration sets in. Clue #3 pops up, the oil pressure gage on the dash never moves until the engine is running. Every healthy 6.0 I have ever worked on will show oil pressure on the gage way before it starts and runs. So what now? Take a look at the oil in the filter housing and hold the plunger down? Check! Now what? Take a master gage of the oil pressure? OK, I removed the oil sending unit and installed my gage. Start the truck and get 80 psi cold…..nothing out of the ordinary there. I warm the truck up and it holds at about 30 psi, not bad. After the truck is shut off and a restart is attempted I get absolutely no oil pressure and it won’t even start at all now. More head scratchin followed by low oil pump removal. I inspected the pump and could fit a .005” feeler gauge between the tips of the teeth on the inner and outer rotors. Well, back on track I go because this thing is whooped!

After the engine was reassembled, it started immediately and had great oil pressure. Another heat up cycle and couple of minutes off and no start or oil pressure. By this time I am talking to anybody who will listen, even bouncing ideas off the guy who sweeps the floors. I decided to pull the oil pan and have a look around. The pickup tube was clear and the pan was fine except for a few bits of injector parts that eventually found their way to the bottom of the engine. Uh, another let down in the quest for finding the light at the end of this dark tunnel. Once again the truck is back together and clue #4 crops up: lots of metal on the drain plug.

At this point, to say that I have a lot of time in this project would be an understatement. The boss wants to get the FSE out and I am ready to throw in the towel. It’s time to fill out a hotline report. I am so frustrated with the whole thing that I don’t want to bother with filling anything out for this truck. I put it out and call the customer to give him a heads up. A couple of days go by and I have some time to think about this thing. One thing is always a constant when working on vehicles, if 10 things can break and 9 have been replaced then it shouldn’t be too hard to figure out what’s left. From day one, I had in the back of my mind that the engine was junk in this thing. I have worked on many many many Powerstroke equipped Fords and I have a good idea of what they sound like. This engine just did not sound healthy the first time I jumped in it. The problem with my hunch was that the thing just runs too good. The vehicle makes rated boost and has plenty of power and throttle response. It defied the logic of how a bad engine should behave. So that idea got crammed into the back corners in the recess of my mind. Then the high volume of oil vapor in the cac tubes, the metal on the drain plug, it just screamed of dusted engine.

At this point there are grumblings in the shop because management wants to get a second set of “eyes” on this problem child. Nobody wants anything to do with it, especially if I can’t fix it. It is time to prove out my bad engine theory and hook up the magnahelic gage to the crankcase. I have never been a fan of using the gage because I have never seen an engine that would even attempt to move the needle. As a matter of fact I have blown into the gage multiple times just to make sure the thing even works. So I block off the crankcase depression regulator on the left valve cover. I install the adapter onto the fill tube, and plumb it to the center gauge on the five gauge bar labeled pressure. In the olden days, Ford’s spec. for this test was 2 inches of water. Now a days it has been bumped up to 8 inches of water. Like I said before I have never seen it leave 0. To say that I am skeptical would be an understatement. I start the engine and a rush of mixed feelings flood over me. I am relieved, excited, surprised, dumb founded, and sad and happy all at the same time. At idle (test is performed at WOT) so as I say at idle the gauge reads 21 inches of water. That’s a 2-1. At wide open throttle the gage almost pegs out and settles at 50 inches of water. The whole time I am running the test the tea kettle effect out of the top of the tool adapter is smoking up the whole shop.

Well, it’s motor time (sounds like Miller time). I tell management and recommend a tear down and piston to cylinder wall clearance check, and get a quote on a short block also. They don’t want to take the hit on the 126 thingy, as usual. So this thing is on permanent hold and I consider myself a free man. These things are gonna drive me right into an early retirement.

cbriggs · March 13, 2011

Wow, thats an unreal story Brad! You should get your magnehelic (manometer) guage calibration checked. I have used ours on a few "good" engines and get readings arouns 3 to 5". I have a 6.4 right now that reads in the mid 20s at idle and pegged the guage beyond 60 by the time it got to 2000rpm. (oddly enough it has a hole in #2 piston and 35ish litres of fuel/oil in the crank case).

Brad Clayton · March 13, 2011

The new recall should fix that piston right up Posted Image

cbriggs · March 14, 2011

OOPS, forgot to try that before I lifted the cab!!

Brad Clayton · March 16, 2011

Reading at idle!

JSHTech · March 19, 2011

Sounds to me like a wild goose chase through a minefield would be more pleasant.

I've seen similar readings on the crank case pressure test though. Lucky for me it was when I first started working, and in my naivety I believed that ALL the diagnostic tests in the PC/ED were meant to be followed and performed religiously, and regardless of the concern. I checked the pressure on a 6.4 that had a lacks power concern, even after I pretty much determined it was the LP turbo, and to my surprise I saw 40 inches of water at WOT. Upon disassembly I found 4 cylinders washed down. Had I not checked it could have turned ugly.

Brad Clayton · March 19, 2011

Oh I agree with you there. Unfortunately, I was chasing a hard start, no start and that test isn't part of the procedure. It's in the lack of power, performance procedure and it's still way down at step 14 of the ladder. That couple with the fact that most 6.0l's don't exhibit high crankcase pressures, this one had the stock air filter, and it runs "good".

JSHTech · March 19, 2011

Unfortunately, I was chasing a hard start, no start and that test isn't part of the procedure. It's in the lack of power, performance procedure and it's still way down at step 14 of the ladder.

And that's my point. It's an uncommon test at the end of the listed diagnostics that most technicians don't often perform. And those are always the ones that burn us aren't they?

They only reason I did it was becasue I was following the book to the letter on one of my first big ticket jobs. And to be honest I haven't done it since.

Where as you had a concern (hard start, no start) you've dealt with many times before, and had experience leading your diagostics, so it's understandable that you wouldn't be reaching for the gauge set first.

Brad Clayton · April 10, 2011

Well this one is all fixed up. I put a short block in it. I also cleaned the intake and cleaned all the valves and put new valve stem seals in. She still fought me all the way to the end. Some jobs are pleasant and some are....well, this one was at the very least consistent. Consistently a thorn in my side. On the initial post repair test drive, the EGR hung up and I had to limp back to the shop. So much for taking the time to clean it up and re "o"-ringing it. Next, the oil pump relief valve access plug "o"-ring sprung a leak. I just had replaced it earlier and we didn't have a new one, I thought it would survive one removal and reinstall but nope. And I lost the driver's side body plug that covers the body bolt access hole in the foot-well. I have been takin bodys off for 15 years and never lost anything that was still in the interior of the truck the whole time. Weird.