6.0L HP Oil leak when warm, already has replacment STC fitting

Mekanik · September 1, 2015

Hello everyone! I'm working on a 2005 F250 with a 6.0L. The customer's complaint is that it shuts off when towing and will restart after ten minutes. I did verify this yesterday when the vehicle stalled on a road test. I was able to confirm that I didn't have enough high pressure oil (about 200psi at the most). I let the vehicle sit for a couple hours and it started right up. I took it back to the shop and air tested the HP oil system. It sounded like it had a leak...This morning I removed the HP pump cover and can see that it doesn't have the latest STC fitting, but the quick disconnect with the bracket. I air tested it and it doesn't have any leaks. Just the small amount of air bleeding out the hole on the back of the pump (a normal amount)

Now I plugged in the block heater in hope that the engine will get warm enough where I can find the leak.

Has anyone seen this before? I know that it should get the latest one-piece STC fitting, but it seems fine now. Any help would be greatly appreciated!

lmorris · September 1, 2015

Those fittings with the bracket can still leak. They were just a quick fix whilst the one piece fitting was being designed. I would take the fitting apart and have a look at it while you have the cover off.

Mekanik · September 1, 2015

Those fittings with the bracket can still leak. They were just a quick fix whilst the one piece fitting was being designed. I would take the fitting apart and have a look at it while you have the cover off.

That's a good idea. My only other option is to put it back together and get it to stall again, then re test it.Do you think the STC fitting would cause it to leak bad enough where the engine will shut off? I really don't think it's a pump. I think it this mechanical pump were to fail it wouldn't just happen when it's warm.

batmantech · September 1, 2015

This sounds familiar, check out this post. 2005 450 no start warm. started aug. 12

Is it gurgling though the oil filter?

Matt Saunoras · September 2, 2015

I don't typically air check hot. If the leak is big enough to cause the engine to stall it should still leak cold too. Air check shows nothing? I would try a good IPR, I keep a tester around and it's usually the first thing I go to.

Steve Mutter · September 3, 2015

I am with Gary, check for air leaking into the low side.

Mekanik · September 4, 2015

I air tested it again and didn't hear any gurgling from the filter housing. So I replaced STC fitting on the pump with the new style. I was really against this, but we gave it back to the customer and it did the same thing.

I took a look at that post batmantech, thanks for linking to that. I have to think that if I did have a leak that was bad enough to shut the engine off i would at least see SOME leak with the engine cold. So it's back to the drawing board!

lmorris · September 4, 2015

Matt suggested the IPR. Did that get done? There is no mention of you doing it. Seems the most logical choice now.

Mekanik · September 8, 2015

I did not replace the IPR, at least yet. I haven't had a chance to look at the truck since it's been back. That is the most logical thing though, you're right.

lmorris · September 8, 2015

One way to test that is to get it so it will stall at the shop and give the IPR a blast of cold water. If it starts up right away, you have your culprit. Used to use a bag of ice cubes on the 7.3L's that did this.

Mekanik · September 8, 2015

One way to test that is to get it so it will stall at the shop and give the IPR a blast of cold water. If it starts up right away, you have your culprit. Used to use a bag of ice cubes on the 7.3L's that did this.

Good idea! I used to bring a couple gallons of cold water when i would go on a test drive with 7.3l's that I thought had a bad CMP.

I looked at the truck and now it has a P2623 for IPR open circuit. I think you're on to something. :chinrub2:

Keith Browning · September 9, 2015

I saw this once on a 6.oL - after about 20-30 minutes of driving the engine would shut off and not restart until it cooled. Passed air test as mentioned. I discovered that the IPR was failing when it got hot. As I recall, the coil resistance went way high as it got hot. Left the meter on it for a couple of hours and watched the resistance come back down. New IPR fixed it. To be honest this was the only IPR I had ever see do this.

Mekanik · September 9, 2015

I saw this once on a 6.oL - after about 20-30 minutes of driving the engine would shut off and not restart until it cooled. Passed air test as mentioned. I discovered that the IPR was failing when it got hot. As I recall, the coil resistance went way high as it got hot. Left the meter on it for a couple of hours and watched the resistance come back down. New IPR fixed it. To be honest this was the only IPR I had ever see do this.

That's interesting. The only IPR's I've seen fail so far have failed due to debris in the screen, and this screen was fine. I had this thing running at a high idle all afternoon yesterday and it didn't stall.I'm going to put an IPR in the truck and we'll probably have someone give it a good road test, then give it back to the customer. Thanks for the reply Keith!

Keith Browning · September 10, 2015

For more clarity on my hot IPR problem - I had the truck running in the parking lot/bay as well but it never failed. The truck HAD to be driven and not just around the block before the IPR would fail. It really needed the engine to get loaded and make some heat. And I concur that most IPR failures are due to debris from my experience. I may even still have that IPR too!

Mekanik · September 10, 2015

For more clarity on my hot IPR problem - I had the truck running in the parking lot/bay as well but it never failed. The truck HAD to be driven and not just around the block before the IPR would fail. It really needed the engine to get loaded and make some heat. And I concur that most IPR failures are due to debris from my experience. I may even still have that IPR too!

Very much like this customer's complaint; it happens when he's towing. I put an IPR on it so we'll see what happens?