[Waylor]

Howdy,

Long time reader, first time poster. I live up in Bozeman, MT and recently drove my 2000 F250 7.3 Super Duty down from here to Texas and back (1700 miles one way). It has 190,000 miles on it. We almost made it to Bozeman, when in Sheridan we suddenly noticed rapid oil loss and some rough idling. The truck was dumping about a gallon of oil over 30 miles, and the entire underside of the truck was coated in it. We refilled the oil and limped over to a buddies place in Sheridan, and that's where the truck stalled. It started back up, but shortly after that it stalled again and would not start. We dragged it over to a mechanic for some diag, and they came up with a bad IPR for the cause of the no start, and misfires on cylinders 5 and 8 causing the blowby that led to the oil loss. According to them, the fact that these happened simultaneously was a coincidence...but that doesn't sound right to me.

I'm backup in Bozeman now, and I need to trailer the truck back up here to fix it. Here's my question: could a faulty IPR lead to piston and ring damage? Or should I start by looking at injectors/cups?

Thanks.

 

[jleedog]

First we need to know where the oil was coming from?

 

[klhansen]

More likely you've lost an o-ring in the HP oil system. Clean it up and track down the leak point.
With some oil still up in the engine, they can restart when oil very low, as the oil drains back down, but will then stall again as the level in the pan drops and the oil pickup starts sucking air.

 

[Waylor]

First we need to know where the oil was coming from?

Oil looks like it's coming from turbo pedestal, but could be the HPOP o-ring. Personally, I'm more concerned by the misfires than the oil leaks.

 

[RT]

No, a bad IPR can't lead to piston or ring damage. Your misfire is likely from air introduced into the high pressure oil system. Injector cups have nothing to do with this at all. If you had fuel in your coolant, then you'd go down that path.

You need to identify your oil leak and fix that. For that rate of loss, you've blown an o-ring somewhere on the pressure side of the HPOP. Look for leaks on the STC fitting on both the HPOP side and cylinder head side of the high pressure oil lines.

Once you get the oil leak fixed and filled back up, run it for about 60 miles to get the air out of the rails and it should quit with any misfiring.

 

[klhansen]

The engine depends on oil to fire the injectors, and as soon as the level gets low enough that the oil pickup starts sucking air, you'll get misfires. So fixing the oil leak should fix any misfires.
Looks like RT beat me to it.

 

[jleedog]

Sorry, I should have went into more detail, but the loss of oil is why its running rough. I'm sure you lost way more than a gallon. Try to clean the engine valley enough to pinpoint the leak then the fix will reveal itself.

 

[30fathoms]

Definitely clean, fill, and recheck for the leak. If it ends up being the turbo pedestal, consider replacing all of the o-rings along the rails while you're in that far. Also, check the oil cooler and the two plugs at the back of the oil rails near the firewall...they don't fail often but while you're in there its worth a check...I find an extendable mirror is cheap and handy for checking hard to reach areas. Best of luck

 

[Waylor]

Thanks guys, I know I'm not out of the woods, but at least I can stop thinking the worst has happened. I thought it would be pretty remarkable to come across engine damage in a 7.3 with only 190k miles on it...here's my question though, did the blow-by push the seals out and cause the leak, or is the blow-by being caused by the misfire and something completely unrelated caused the leak?

 

[30fathoms]

Waylor, what are you referring to when you cite "blow-by?" I'm certainly not the resident expert on here but I have learned the following: the 7.3L can dump a tremendous amount of oil depending which o-ring/connection/system loses integrity. If air is introduced to the oil system during the failure, your motor will run rough and it will take some driving before that air is purged. My first step is always to clean everything really well and identify the oil leak; HPOP/IPR can leak into the valley and escape out the back of the motor by the firewall, turbo o-rings and rail plugs same same. I wouldn't suspect a serious internal problem unless it still runs rough after the leak is corrected AND the air is purged. 190K is not necessarily too early to have o-ring failures depending on how hard the truck has been worked and/or how well it was maintained. good luck

 

[klhansen]

We dragged it over to a mechanic for some diag, and they came up with a bad IPR for the cause of the no start, and misfires on cylinders 5 and 8 causing the blowby that led to the oil loss.

Your problem is listening to that mechanic who couldn't diagnose it correctly. Why would misfires cause blowby on an engine that was otherwise in good shape? Blowby is combustion gasses leaking past the rings into the crankcase, and that will not cause the kind of oil loss you're seeing.
I'll say it one more time: Track down the source of the oil leak and fix that.

 

[Waylor]

UPDATE

Wow this has been a long process. I tracked the leak down to either the turbo pedestal or the HPOP and replaced both. Took her for a test drive after replacing both of these components and drove around for about 10 minutes before the truck stalled coasting down a hill and wouldn't start back up. It didn't have much power when I was driving it around. Flat towed it back to my buddy's place, didn't lose any oil, but I did find some on the turbo that wasn't there before. Also, the green line that runs from the intake to the waste gate solenoid was broken. Any suggestions on where to start now? I'm thinking blown boot maybe...or maybe the turbo is bad...and I don't really know if breaking that green vacuum line would lead to a stall/no start scenario.

Also I should say it isn't throwing any codes.

In summary:

1. New HPOP and Turbo Pedestal
2. Leak is fixed (?)
3. Oil on turbo
4. broken green vac line
5. No power, ended up stalling and won't start

 

[jleedog]

Broken green line wouldn't cause a stall. Did you replace your IPR? That is what I think your problem is. Are you getting any codes? Are you able to read any running parameters?

 

[Greg687]

I agree that the green line, blown boot, and bad turbo scenarios would not cause a no start. Is it cranking when you try to start it?

 

[Waylor]

IPR was changed by the shop I took it to for initial diag, and then I reinstalled it on the new HPOP when I put that in. I could check the torque on it.

 

[klhansen]

You may have unnecessarily replaced the HPOP. They rarely fail, although at times the o-rings can fail, but those are easily replaced without replacing the whole pump. Seems like you could have differentiated the source of the leak to one end of the valley or the other. But that's water under the bridge.
Anyway, if you're still having start issues, you need to check for HP oil pressure. It needs at least 500 psi to start. You might try unplugging the ICP sensor which will override the signal that the PCM is getting and use a default value. If there's oil in the sensor, that indicates it's bad and should be replaced.
Are there any codes or check engine light on?

 

[jleedog]

A blown boot would definitely give you a loss of power, but I believe that would be easy to spot that problem and wouldn't cause a stall. Did the shop you used replace the IPR with a genuine Motorcraft part? You really need a way to look at some numbers, can you invest in Forscan?

 

[Waylor]

@klhansen Thanks for the insight on the HPOP. Realistically, this is something I realized, but wanted the piece of mind knowing it was replaced with a new unit. Either way, the reinstall fixed my initial leaking issue.

I did try starting the truck with the ICP sensor disconnected, and the sensor is relatively new as well. Didn't help with the no start issue.

No codes, but there is an intermittent "service engine soon" light.

@jleedog I could probably invest in Forscan. If I did, what numbers would I be looking for? The new IPR was indeed a motorcraft one.

Thanks guys.

 

[klhansen]

No codes, but there is an intermittent "service engine soon" light.

If your scan tool is a generic one, it won't pick up codes. Has to be Ford and PSD capable.

 

[DonWarkentin]

Since you are still leaking some oil, but not as much as before, is it possible that the HPOP was replaced, but not the o-rings where the oil lines from the HPOP attach to the oil rail. Those o-rings frequently leak also. You can get those o-rings from here. Ford 7.3 Diesel Engine O-rings and Plug Gaskets

Get the Forscan here. Download FORScan

You will need the OBD adapter also. The link for that is on the Forscan website link above.

See if you get any codes with that, and post them here so that we can help you with the diagnosis.