2001 7.3 using oil

[60cents]

My 7.3 just started using oil. Took it in for an oil change and was told that there was no oil on the dipstick.
I had just checked it a few days ago and it was 1/2 quart down. When I take the filler cap off I can see smoke coming out in puffs as in maybe one cylinder is leaking. My mechanic has pulled the air cleaner and smoke was coming from there as well. There was oil in the intake hose going to the turbo. He checked the PCV valve and that was not plugged. The turbo is tight also. Whatever happened just did.
My mechanic says that probably there is a broken ring or a valve problem but there is no valve noise and the engine idles smoothly.
To further complicate the issue I just added 9 gallons of B100 biodiesel to top off the tank and have driven 290 miles since I did that. It is possible that the biodiesel has cleaned the system enough to allow oil past the ring(s) but not too likely.
This truck has 186000 miles.
What are other possibilities that might cause a puffing oil filler neck???

 

[BJS]

injector o-rings will cause oil to get into the fuel, then into the cylinders to get burned. Sadly on the SD engine with the deadhead fuel system you can't use the check the fuel filter test that the OBS trucks use because your fuel is not recirculated after it would have the chance to get contaminated.

There should not be smoke comming out of the air cleaner when the truck is running at all no matter what. the crank case vent yes and possibly but not a ton.

How much is puffing, a small amount is acceptable, large quantities are not.

What if any modifications have you done to the truck? a K&N air filter? if so or this is good to check anyway pull the intake off of the inlet of the turbo and examine the turbo fins. the edges should be clean crisp edges no ripples or ridges and the blades should be smooth and almost shiny. If the blades look sandblasted, pitted or otherwise strange or there are ripples in the edges then you have a "dusted" motor which means that your air filter has failed at effective filtration and more than likely the middle 2 cylinders on the driver's side are loosing compression.

Easy test is to have your mechanic do a compression test it will reveal all of the problems that you're questioning other than the injector o-rings.

As a suggestion if you need new 0-rings get the injectors completely refurbed.

 

[60cents]

Thanks for the info.
It wasn't smoking from the intake when it was running, only after it was shut down.
The puffing is at idle and not a lot but certainly visible.
There have been no modifications and the turbo fins are fine.

 

[dpantazis]

1. get a second opinion. i don;t know of a PCV valve on the 7.3. a PCV hose to the intake, yes. but no PCV. that is why you hvae oil in the hose btwn the intake and the turbo.

2. the 7.3 won;t start if its 3 qts low. there is a low oil sensor and interlock. may be more like 4, but something like that.
1/2 quart is nothing. you could use 1 qt/1000 and still be fine.

3. ALL engines have blowby. how much is another issue. blowby out the intake at idle? that does not sound accurate. that means that the net airflow is OUT of the intake, not in. that does not sound accurate. what is your air filter?

4. you sure there are not any leaks anywhere?
turbo pedestal, hpop, oil filter? rusty oil pan? wash the motor good, put dye trace in and look it over carefully.

5. a compression test would be the best thing to do check the cylinders/valves. but they are costly to do.

6. i think that bio is a coincidence. you topped off with 9 gallons, so 9/40 concentration, or about B25-B20? not likely. i would think that the bio would have caused fuel filter or fuel line failure. but, stanger things have happend.

 

[60cents]

Sorry for the confusion. I guess diesels have CCV's not PCV's.
Smoke from the intake was after the engine was shut off.
I don't think the addition of biodiesel is the problem but maybe someone else has had this experience.
How do you do a compression test on a diesel? Do you pull the injectors or the glow plugs?

 

[BJS]

compression test is done by pulling the glow plugs

 

[iracemine]

2. the 7.3 won;t start if its 3 qts low. there is a low oil sensor and interlock. may be more like 4, but something like that.
1/2 quart is nothing. you could use 1 qt/1000 and still be fine.

1. get a second opinion.

X2.

 

[JLDickmon]

1. get a second opinion. i don;t know of a PCV valve on the 7.3. a PCV hose to the intake, yes. but no PCV. that is why you hvae oil in the hose btwn the intake and the turbo.

2. the 7.3 won;t start if its 3 qts low. there is a low oil sensor and interlock. may be more like 4, but something like that.
1/2 quart is nothing. you could use 1 qt/1000 and still be fine.

3. ALL engines have blowby. how much is another issue. blowby out the intake at idle? that does not sound accurate. that means that the net airflow is OUT of the intake, not in. that does not sound accurate. what is your air filter?

4. you sure there are not any leaks anywhere?
turbo pedestal, hpop, oil filter? rusty oil pan? wash the motor good, put dye trace in and look it over carefully.

5. a compression test would be the best thing to do check the cylinders/valves. but they are costly to do.

6. i think that bio is a coincidence. you topped off with 9 gallons, so 9/40 concentration, or about B25-B20? not likely. i would think that the bio would have caused fuel filter or fuel line failure. but, stanger things have happend.

Dang, Dennis..
You'd think you do this for a living, not restoring turn of the century hi-rises..