Hey guys. I’m new to the forum but I’ve read these forums plenty over the last few years. I’ve got an 05 w/ 345k on it. Bought it with 300k and haven’t had any major issues until recently my wife couldn’t start it while in town and when I got there I checked the oil and it wasn’t on the dip stick. I figured there was a low oil sensor that wouldn’t let it start. I had been running t5 and changing every 5k but the last oil change I couldn’t find t5 so I filled it with t6. Anyways filled it to the mark, and it took 4.5 qts after changing the oil 1800 miles before this. And it still wouldn’t start and by this time I had to jump it off a friends truck to get enough power to crank it. After it charged up I checked the oil again and after cranking it was a tad low again so I filled to the top of the hash marks and it started right up. Drove it home 15 mins and shut it off, now and it will only start when it’s cold besides some random exceptions. Im not even sure the oil consumption is connected to the hard start or not but any advice is appreciated! The valley of the engine bay is dirty and is moist with oil but there are no obvious leaks. The truck sat for 2 weeks and there’s not a spot on the ground. My ccv is flowing just fine. Checked shaft play in the turbo and it won’t move in any direction and spins freely. Not an excessive amount of oil in the charge pipes. Previous owner claimed the engine was rebuilt at 220k but I don’t have any real reasons to believe that. It’s bulletproofed and the egr is deleted.
When the truck does start it runs very smooth and has plenty of power. No smoke other than a little blueish haze when you first crank it and until it’s fully warmed up. I’ve read some say the Injector o-rings could be the cause and to check the fuel bowl so I did that and it’s perfectly clean no hint of black there. My batteries are weak and I will be replacing them this week sometime but even on a solid jump after charging them I can get the engine cranking as fast as it ever would with no luck. Thanks for the advice in advance!

 

Also the times is does start it fires up perfectly. That’s why I’m curious if it’s a separate issue than the oil consumption. Before this episode it used a little oil, maybe a qt or two between changes.

 

The injectors are actuated by oil that is supplied from the high pressure oil pump. If the oil level is run down enough the high pressure oil system will be starved from oil as base engine lubrication comes before feeding the high pressure system. This can cause the truck to die. Once the oil level is restored the system will have to bleed out the air that is now in it before the truck will start. I would start by cleaning the engine well and then inspecting for gross leaks. If there is one it is likely to be the oil pressure switch in the valley, just behind the oil filter housing. It is a single wire switch, common to fail and when it does it will pump out a lot of oil in a short amount of time.

 

Thanks for a quick response!
That would make sense for sure. How much engine run time would it take to bleed the system? Since I drove it home 15 mins and it’s probably idled another 20+ mins at home between different times I’ve been able to start it. Or is there a process to bleed the high press oil system?

Sounds like a good place to start. I’m hoping to clean it up and check that out this week after work. That switch should only work with the engine running correct?

*Edit Did a quick YouTube on testing an oil pressure switch. Looks like you can test it with shop air and water. I’ll be trying this tomorrow or the next day for sure.

 

That amount of driving and running should have gotten most of it out. Best way to check the switch is get the truck running and disconnect the connector. If it’s bad it will push oil out through the connector.

 

Hey that’s even better. I’ll be trying that today sometime.

 

If the batteries are weak as you say, get those replaced ASAP as well. Weak batteries will destroy your FICM in very short order. I learned this the hard (expensive) way.

Otherwise it sounds like you're likely on the right track.

 

Wow I would not have guessed that. Always nice when you don’t have to learn the hard way lol thanks! I took them out this morning and I’ll be getting another set on my way home.

Edit* Gonna wait till tomorrow to get batteries, they’re gonna be in stock by then. Or so they say.

 

Sorry for the lull. Works been keeping my out late. I just put the new batteries in and cleaned up the oil pressure switch and then let it idle up till operating temp and took it for a 5 mile run. It drove great and ran normal. Oil pressure switch stayed dry and I noticed in the crack between the oil cooler housing and the block there was a tiny bit oil setting there. Enough that I’ll probably be digging into that area soon to try and find exactly where it’s coming from. I’m guessing it’s the oil cooler seal but I could be wrong. When I got back from the drive though my oil gauge was wacking out dropping to 0 and then back to normal randomly but about every 5-10 seconds. Never changed how it ran a bit but I shut it off and now it just cranks and won’t fire.
the first time I tried starting it after I initially shut it off it cranked and didn’t start then the second time it did start but after about 5 seconds of cranking. Drove it a half mile after this happened and parked it and now it won’t fire at all. The oil pressure switch wouldn’t cause this if it had bad connection or anything would it? It started with it unplugged the first time today anyways…