[jsohc]

I have 2001 Excurison. It is drinking oil. I have asked every one I know. Comes down to two answers. Turbo seals or a Injector o-ring. Happened all of a sudden. It will use 2 quarts in 50 miles. No leaking no smoke. Injectors have arond 20,000 miles since new. Question is how can I figure out what injector is leaking if it is? No crap I have put over 16 quarts of oil in it to keep it on the stick. It never used oil. Maybe a quart every 5 months. Thanks for any help.

 

[RT]

There is no easy way to tell which injector o-ring if it is a lower ring. That's the one that will be leaking if the oil is disappearing. The upper ring would just push oil back into the valve area where it would go back to the crankcase. A turbo seal leak as bad as you have would be billowing smoke and actually have oil dripping out of your tail pipe. Time to bite the bullet and just pull all the injectors and re-ring them.

Edit - one caveat - if all your injector o-rings are perfect, then you likely have an injector that has internally failed allowing oil to pass internally to the fuel side. Rare, but it does happen.

 

[jsohc]

Thank you !!!

 

[Oneof6]

There is no easy way to tell which injector o-ring if it is a lower ring. That's the one that will be leaking if the oil is disappearing. The upper ring would just push oil back into the valve area where it would go back to the crankcase. A turbo seal leak as bad as you have would be billowing smoke and actually have oil dripping out of your tail pipe. Time to bite the bullet and just pull all the injectors and re-ring them.

Edit - one caveat - if all your injector o-rings are perfect, then you likely have an injector that has internally failed allowing oil to pass internally to the fuel side. Rare, but it does happen.

I do agree with RT 100%, turbo seals or oring ... one would not be doubt about it. One could confirm the oil >>>> fuel side leak by pulling the fuel filter it will be the color of old oil, black.
Likely time for an injector o-ring R&R, or more. It's an opportunity to consider miles and hours vs what one's expectations and intentions are for the unit.
For instance, high mileage on the original injectors, mechanically justified in replacing them. No better time for an injector swap to change injector cups, injectors, glow plugs, VC gaskets and UVCH's.
I like a system in some sort of common condition order. Not like new boots and old socks.

 

[TooCoolTwo]

As usual, very solid advice from RT and Oneof6.

 

[Maryland dieselnick]

I would not be pulling injectors yet.
The turbo has 2 seals. If the one on the exhaust turbine seal was leaking bad, you would be blowing alot of smoke because it is hitting the exhaust right away. If the seal on the compressor side is at fault, it will pump down and up through the intercooling path before being sent into the engine. You want to disconnect the boots at the intercooler and see how much oil is there. There will be a bit due to the fact that the engine breather goes to the intake. Pull the intake to the turbo and see what the compressor housing looks like. Also see how much play is in the wheel.You want to check these things before going through pulling injectors.
Generally oring or injector failure results in pretty noticeable smoking.

 

[panhead george]

I would not be pulling injectors yet.
The turbo has 2 seals. If the one on the exhaust turbine seal was leaking bad, you would be blowing alot of smoke because it is hitting the exhaust right away. If the seal on the compressor side is at fault, it will pump down and up through the intercooling path before being sent into the engine. You want to disconnect the boots at the intercooler and see how much oil is there. There will be a bit due to the fact that the engine breather goes to the intake. Pull the intake to the turbo and see what the compressor housing looks like. Also see how much play is in the wheel.You want to check these things before going through pulling injectors.
Generally oring or injector failure results in pretty noticeable smoking.

So if there is oil dripping from the intercooler boots, then chances are the seal on the compressor side leaks?

When I start mine up in the morning, there is always smoke out the exhaust until it warms up. Today EOT was 28* on the scan gauge.

How much oil should be coming out the intercooler boots OR boots at the intake manifold?

 

[Maryland dieselnick]

You are always going to have a little. If you pull the boots, it will be wet. If oil is running out, that’s not good.
A bit of smoke for a few seconds after it lights off when it’s cold is normal.
If you have one or more glow plugs out, it will smoke heavier and longer as you are burning some raw fuel.
The heater in the compressor manifold is there to cut down on smoke at start up/ warm up when it’s cold out.

 

[Maryland dieselnick]

An engine that is really drinking it up might not have much visible smoke if the leak is at the compressor side of the turbo because it’s being evenly distributed to all 8 cylinders. Conversely an injector/ injectors based issue, it’s going to be isolated two one or two cylinders. The volume of oil this guy is talking about, it’ll almost always be visibly notable. Oring failure usually also results in a notable difference in performance as the hydraulics at the injector/injectors will not operate it/them the same.
Its the thing to check out first before spending the time on injectors plus the money for materials even if they turn out ok.

 

[RT]

An injector o-ring leak is going to allow oil into the fuel rail. Because of the rail design, the drop in pressure will be felt by all injectors on that bank equally but may be less than you would expect. A hole big enough to cause a significant drop in pressure in a running engine would drain the entire oil supply in less than an hour. You're only losing 2 quarts in that period of time.

I've never seen one turbo seal fail independently of the other. Maybe Nick has. I'm standing by my injector o-ring diagnosis.

 

[realdann]

An injector o-ring leak is going to allow oil into the fuel rail. Because of the rail design, the drop in pressure will be felt by all injectors on that bank equally but may be less than you would expect. A hole big enough to cause a significant drop in pressure in a running engine would drain the entire oil supply in less than an hour. You're only losing 2 quarts in that period of time.

I've never seen one turbo seal fail independently of the other. Maybe Nick has. I'm standing by my injector o-ring diagnosis.

Then the diesel fuel should be getting a dark tint to it because of the engine oil intrusion pass a faulty oil oring.
With the stock fuel pressure near 50 psi in the heads and in just considering idling pressure of 700 psi in the HPOP system, an oring fault in this case would pump tons of oil into the fuel system in a matter of moments. Would it not?

This would make leaking turbo seals more likely cause. Because where is the oil going? Is it in the fuel? Is it in the water? Is it on the ground? Or is it being burnt and going out the exhaust?

 

[RT]

A fully torn o-ring can undoubtedly lose that quantity of oil. But, injector o-rings rarely spontaneously rip in half. They begin leaking slowly. Oil gets pushed into the fuel rail. Yes, if your oil is black, it will stain the filter black in time, but remember the stock system has dead-headed fuel rails, so in the early stages, it just gets burned. And a 7.3 will burn oil just fine. I've actually experimented with waste motor oil as fuel and up to 75% oil and 25% diesel smoked very little. Injector o-ring failure causing oil consumption is a known problem in this engine. Actually, probably the number one cause in all HEUI engines. The usual cause of a blown turbo seal is excessive play due to bearing failure. For a shaft to wobble enough to destroy one seal but not the other would be weird. If they both fail, then, you'd have unburned oil in a hot exhaust. That smokes and oil drips out of the tailpipe. Again, a very common cause although much less common than the o-ring.

There's a saying in medicine. When you hear hoofbeats, think horses, not zebras.

 

[realdann1]

Then one can remove the fuel plugs in the heads and catch and inspect the fuel that drains out. Air blown into the fuel supply lines to heads should show oil on a white shop towel.
Just go ahead and do a fuel bowl delete while you're at it. No more dead end.

 

[Maryland dieselnick]

I don’t hear hooves when I am wrenching. I have Van Halen’s “ Let’s Turn This Around/Right Now” ( It’s my company’s song). Check it out with lyrics on YouTube. I go through a series of checks.
If I have excessive oil consumption ( in excess of 1 quart per 900 miles).
I am:
Taking for a test drive to see how it performs.
I am checking for smoke
Checking crankcase pressure. I look to make sure I am less than 4 inches of water column.
I am looking for elevated duty cycle.
I am looking in the fuel bowl.
I am pulling intercooler pipes back from intercooler.
The exhaust turbine seal need not be shot for oil to be pumped through compressor side seal.
Rock on

 

[Maryland dieselnick]

I am quite certain that there is a saying among cardiologists that goes, “ Make sure that heart is clogged up before going in for a bypass”. May not be but I am certain that it is an understood thing.
You never want to tell a customer, I gotta go in and pull injectors and that’s not it.
You have kept him from his truck longer than necessary.
You don’t look good with your diagnosing skills.
You have lost money in billable time.
You are spending your own money in materials just to get back to where you were when the truck came in plus more money lost in billable time.
Not the way things should happen and will result in 😞 and maybe 😡

 

[Maryland dieselnick]

Fuel bowl is not the the dead end. The pressure regulator is the return to fuel tank.
a leaking middle oring will cause smoke when you put it to it and the PCM ramps up pressure command. The amplifier piston will not perform
properly because it not getting the proper pressure resulting in incorrect fuel delivery to that cylinder.

 

[RT]

Thanks for that, Nick. This is a diesel forum, not a psych ward - as much as it may seem like it at times. The inmates are mostly friendly and generally know what they are doing.

I would like to clarify, on the cardiac analogy. Coronary artery occlusion would be verified with an angiogram and the stents would be placed at the same time. There are some non-invasive tests that would lead you to do an angiogram, like cardiac CT and nuclear stress testing, but the definitive test is still invasive and the treatment is administered at the same time as the test. Carrying over to the injector scenario - you pull them to see if the o-rings are torn and replace them while you have them out.

That said - maybe medical analogies should be left out of the conversation from now on.

 

[Maryland dieselnick]

Exactly. They know before hand. I had been saying that, well you read it.

Hope the Eagles are still hanging out.

Adams, Two sayings here in America that come to mind.

Never get between a Rebel and a Yankee.

Those who can’t do, Try to teach