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Please help!. I have been trying to keep this thing running with little experience and no cash flow for mechanical expertise. My husband bought this truck about a year ago with a oilleak that loses about a quart every few weeks or so. I had hi hopes that my husband would investigate it more thoroughly and see where it was coming from. This is the only vehicle that I have to drive now. my husband left our home a few months back leaving me to figure out the problem myself. I'm okay at figuring out problems but this is too big. About a quart every 4 days is what it's losing now. I had just changed the oil in it and it was too quart shy of being full when I made it back to town and added the other two quarts. I drove it about 3 days and it was driving and running fine until couple days ago I started it and it was really hard to start even though I had it plugged in and it wasn't real cold that night. once it started it ran just fine until I got about 20 miles down the road about a mile from dropping my child off at school.. it lost power going down the highway at 55 mph and I coasted to the side of the road .I noticed the oil pressure high low gauge was low not registering so i check the oil and it was full got underneath and noticed that it was leaking noticeably steadily from the rear main seal cover as though there was a hole in the middle of it. I was able to get a ride to the local mechanic who is not a diesel mechanic . He drove out there with me and and rolled under it while I tried to start it he said that it was gushing from above the rear main seal and and running down the cover. I really don't have the funds to pay for this to get fixed and every diesel mechanic in the area which is 45 miles at the closest has to keep the truck for a couple days just to diagnose it and I don't have anything else to drive so that's been my delay at getting it aken care of in the first place and now I'm on foot 20 miles from town, trying toi run a business that requires that truck to pull my horse trailer. I am at my wits end and I just want to know engine is leaking and can I fix it. My first thought because of the oil pressure symptom is that it's the oil pressure sensor that caused the gauge to register no pressure . Could it be leaking from wherever that ties into the oil system. Obviously I don't know what I'm talking about but I have determination and desperation pushing me on to delve into this myself. How do I know if it's destroyed the engine or if it could be just something as simple as an oil pressure sending unit and if so I cannot figure out definitively where the heck the oil pressure sending unit goes. I've searched it in on all these forums there's so many conflicting locations Can anybody help me figure this out please...I'm at my wits end, out of solutions and about to shove my husband into the engine of this truck if it's possible. That that would help
 

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So, everything’s kind of a guess at this point but the fact that it ran good while running seems like a good sign. You going to need to Google some pictures of the 7.3 PSD to familiarize yourself with the parts. It is not uncommon for a bad leak on top of the engine to build up in the valley and run down the back of the motor where you initially described (rear main seal).
If you had a line on the high pressure oil pump leaking badly this would happen, The low pressure oil pump lifts oil up to the HPOP. On the top of the HPOP there is a plug, That needs removed and inspected to see if oil level is low from a blown hose/seal (bad leak). Our fuel injectors can not fire without that oil pressure from the HPOP even though there may still be oil showing on the dipstick. I’m wanting to say the 7.3’s hold 15 quarts of oil with filter. If the HPOP is low you could add oil at the plug, clean up the valley real well, and have someone watch for where the oil is leaking if the truck fired up. Hope this helps you to diagnose.
 
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Good, morning. First, as to your most important question regarding how do you tell if you "destroyed" the engine. That's complex, you are not there yet for that consideration.
It is unlikely, just from your event description, that you have. The most likely two things ( not the only possibilities) that would cause your reports of oil pressure loss, shut down, big leak off the engine back and no re start are ...... loss of the low pressure system oil from leaking HPOP line o-rings and or Turbo Pedestal o-rings. Oil coming off the engine valley rear and down by the main seal is often mistaken for a rear main seal leak. Rear main seal failure is rare, it's not a common thing.
Here's how your oil system (s) works. There are two systems, low pressure and high pressure. Low pressure supplies overall engine needs and the supply oil to the high pressure oil pump system. The high pressure oil pump system provides high pressure oil to operate the injectors, which are electrically controlled but hydraulically actuated.
When the LP oil volume is reduced or eliminated the engine quickly uses the 1-2 qts oil in the HP systems reservoir. Then having no HPOP oil stops actuation of the injectors, which shuts down the engine and it can't restart, which is a good thing, from a perspective of destroying the engine
Soooo, it's a good thing it shut itself off, its supposed to when the oil volume gets too low to supply the HPOP system, entirely predictable and unlikely it has "destroyed" anything at all.
 
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Discussion Starter · #5 ·
Oh now that you mentioned about the hpop and that two quarts of oil causing shutdowns it reminded me that over the course of the time I've had the truck every once in awhile it would shut itself off while I was driving but it would immediately start back up. I finally noticed that it would be a quart and a half or two low on oil when this happened and it cut out. Does this mean that the component specific to the hpop would be at fault or does that information reveal anything at all? I'm so not experienced with this so forgive me if I'm asking dumb questions that have already been answered in your replies
 

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Discussion Starter · #6 ·
I should probably clarify that when that it had cutout I meant on previous times that it shut itself off and started back up it would be cutting out along the way as well but didn't do anything of the kind this time when it shut down and wouldn't start back up and showed low pressure. This is the first time showed low pressure
 

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Twee3090

For clarity, when I wrote about shutting down after using up the the 1 to 2 qts in the HPOP, I was referring to, in parallel, the LP system being so low as to not be able to pump and constantly resupply the HPOP system.
Visualize it this way, low pressure is supplied by the engine oil pan capacity, 16 qts, to the HPOP reservoir, at engine oil pressure, it keeps the HPOP reservoil system constantly full. That HPOP system takes that reservoir volume and it's output is typically from 500 PSI up, that's injector operating pressure, compared to the low pressure system HPOP is low volume high pressure. The low pressure system would have to be very very low gallons to not be able to supply the skimpy 1-2 qts to the HPOP to disable the injectors.
Unless your 02 is different from mine, I don't get any oil pressure indication on the dash gage while cranking, are you using the dash gage or an aftermarket gage?
Your prior intermetent shut downs while driving a couple if quarts low don't fit a low hpop scenario.
What to do first? As Big Horn recommended check the HPOP reservoir level, it should be within 1/2" of the top. If it's full now then you may have big leaks but that didn't shut you down. If it's, hpop, empty, it will never start.
You noted an oil change, do you remember what brand and grade of oil you used?
Sometime during this process you will be tempted to use starting fluid to get going, please don't, that IS a way to destroy a 7.3, despite what a local Billy Knob says his Uncle Gomer taught him to do with a divining rod.
You are certainly having a Adventure opportunity, might be a movie in it.
 
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Discussion Starter · #8 ·
I used a fram filter and shell t6 full synthetic and I have the original gauge in dash. Can't remember now if I had numbers or only indicates high/low. When I get back to truck in a few hours I'm going to check out all you both have outlined here. Thanks so much
 

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If I got paid a lot of money or just enough to get this fixed and going then all this would be worth it to make a movie.lol. I learned not to use starter fluid. When my husband destroyed the first diesel we owned by using it
 

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I used a fram filter and shell t6 full synthetic and I have the original gauge in dash. Can't remember now if I had numbers or only indicates high/low. When I get back to truck in a few hours I'm going to check out all you both have outlined here. Thanks so much
That's good oil and a acceptable filter. Some automotive oils are not good applications for 7.3 injectors, oil foams in high pressure and causes runability issues, haven't seen a case in a very long time.
 
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Discussion Starter · #11 ·
The reservoir is totally empty and a little plug I took out isn't that the pressure regulator sensor? And my gauge is just a high low reading factory gauge. I'm going to have somebody help me tomorrow I ran out of help and daylight to check to see where leaks were coming from after I fill it. While I have that sensor out should I put my new in? I bought one just in case and that was the only issue or part of the issue
 

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There is an oil pressure sensor (of sorts) mounted in the top of the HPOP reservoir. One could use that sendor position to check the reservoir oil level. However, most don't use that sender port just to check level. There is a simple verticle plug in the reservoirs top that most use to check the level, no wires just a plug, in the rare circumstances requiring it, without pulling out the sensor. It's a good practice to work very clean when open up the HPOP reservoir, any grit or debris introduced will not have a filtration element between it and the injector plungers that HPOP oil powers.
 
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Discussion Starter · #13 ·
There is an oil pressure sensor (of sorts) mounted in the top of the HPOP reservoir. One could use that sendor position to check the reservoir oil level. However, most don't use that sender port just to check level. There is a simple verticle plug in the reservoirs top that most use to check the level, no wires just a plug, in the rare circumstances requiring it, without pulling out the sensor. It's a good practice to work very clean when open up the HPOP reservoir, any grit or debris introduced will not have a filtration element between it and the injector plungers that HPOP oil powers.
I didn't realize about dirt getting in there..and so I opened up that plug with the wire coming off of it.(fhe only plug I saw on top of the reservoi) and didn't pay much attention to keeping it free of any grit or debri.all I I did was take it off and look and then shut the hood so hopefully nothing from the hood fell into that reservoir as I stupidly didn't plug it back up. Is there a way to ensure after the fact that no debris can get through?
Darn I hate that I know nothing and shouldn't be doing this.. and do I need to put the plug back in before I start the vehicle to check for leaks?. Of course after filling with oil? And how long can I let it run while checking for leaks? Sorry for all the stupid questions.like I said I'm completely ignorant other than what I've learned here today.. I didn't see any fresh oil around the reservoir but was very wet and oily in the valley. .. how will I see if any leakage is coming from the oil pump o-rings from lines that go into it if I don't take out the housing for the fuel filter first since the fuel filter seems to be on top of the pump.?. And should I degrease that area before even trying to check for leaks?
 

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And should I degrease that area before even trying to check for leaks?
Yes
and do I need to put the plug back in before I start the vehicle to check for leaks?.
Yes
how will I see if any leakage is coming from the oil pump o-rings from lines that go into it if I don't take out the housing for the fuel filter first since the fuel filter seems to be on top of the pump.?.
you have to view from on top of the engine. Be very careful of rotating components, fan, belt, alternator, and make sure the Power Stroke plastic cover is removed. As soon as the engine starts you should be able to see leaks if you have the valley clean. Have good lighting or a shop light / flashlight.
 
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Every word Big Horn wrote is true, and appropriate. I would add for specificity fill the HPOP prior to trying to start. Fill the engine oil to FULL and have some additional make up oil with you, in case this thing actually starts up, has a leak but a leak that you can keep LP topped off until you get it somewhere else closer to your base get more help point. Don't expect it to run well at first if it does start.

Any roadside repair of turbo or HPOP oil rings by an inexperienced person is ultra low probability of being sucessful and very high probability of worsening an already bad set of mechanical and financial circumstances.
 
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Yes, one must put the HPOP plug back in, or, they will have a lake of oil in all the wrong places.

No time limit on checking for leaks. If it's running, has oil pressure and appropriate oil volume in the engine look until you find the leak (s)
 
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One thing that can help in checking for leaks is sopping up all of the accumulated oil (there should be a lot in that valley) before you go to clean with water and degreaser. I usually find a sacrificial towel.
 
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After 20 posts is a photo of this now infamous leaker available?
 
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