Oil consumption increasing

[markrinker]

I have noticed the oil consumption on #2 increasing, especially after heavy loads pulled at high speeds. Recently burned 1 quart in under 1000 miles pulling 10K lbs about 70mph average. (Remember I have 4.10 gears...)

No oily smoke on start-up, no oily exhaust pipe, no signs at all except the low dipstick. No blow-by noticeable at the oil filler tube at idle, and the truck makes lots of power.

Where is all the oil going?

[Dvldog 8793]

Howdy
No matter how impossible it may seem when all other possible options are gone the only thing left is the answer.
If it ain't leakin it's burnin.
Check to see how much oil is in the CDR(PCV).
L8r
Conley Janssen
USMC 87-93

[markrinker]

#2 is definately burning it, but I don't believe it is bad rings, based on observation of little to no vapor at the filler tube.

#1 has always puffed lots of oil vapor out the filler tube, but hardly uses any oil at all.

How else can these engines start to burn excessive amounts of oil?

[Uncle Wally]

Valve guide seals?

Waldo

[Dvldog 8793]

Is it possible for the valve seats to leak like the Chev small blocks? Granted for it leak that much it would almost have to be gone. There are only two ways into the combustion chamber, past the rings or drip down the top. My first motor would drink about a .5 qrt per 2500miles. It always had a little puddle of oil in the intake right infront of the turbo under the PCV intake tube. It never showed any vapor or blow-by at the oil fill tube.
L8r
Conley Janssen

[Kennedy]

How's your air filter? Is it sealed to the box well?

[markrinker]

Air filter is okay, John. I replace paper elements every oil change - which is about every 4-6 weeks.

What affect would a bad filter have? Rings?

[markrinker]

I am leaning towards the valve guide theory, especially because this motor has always been in front of 4.10 gears and is over-revved at highway speeds as a result.

Would one of the those rubber bushing over the valve stem kits help? I am planning to do glow plugs and injectors soon, maybe just pull the valve covers and try this as well.

Its not that expensive, I am tired of dumping oil through this motor.

[jspringator]

If it were valve guides, wouldn't you have oily smoke on startup? My parents used to have a VW 411 that did this.

[norm]

I am using some oil, too. A quart per 1000 miles. Generally I cannot see smoke from the exhaust, but at night when in the throttle/boost and car lights behind, I can see it blow pretty good. I guess the fog is too light and dispersed to see in daylight.
I am not happy with the consumption, but can't afford to do anything serious with the motor right now, and it runs ok, so I put some oil in.

[JohnC]

I would be surprised if these engines use a lot of oil past the valve giudes. Most gas engines leak past the intake guides, in part due to the constant vacuum in the intake system. A Diesel has minimal vacuum, and if turbocharged, generally runs pressure in the manifold. Ditto the exhaust system.

One way for oil to get into the intake (or directly into the exhaust) is through the turbo seals, especially if the turbo oil return line is not doing its job.

[john8662]

Just want to add something to this discussion. My 95 is making some odd noises at idle in "uneven clack, clack, clack even with new injectors" post and have just noticed increased oil consumption. Upon doing a compression test (results in the post) I had to take down my downpipe to get to #6 cylinder, so I had to remove my airbox and turbo plumbing. While removing the hardware to get better access to the turbo downpipe clamp I noticed everything was oily! There was oil sitting before the turbo inlet, and the intake seems to be seeping badly (was perfectly clean). Oil was leaking from my boost sensor tap, from the 6 bolts holding on the upper intake, and around all the sensors on the intake! What gives? I pulled the dip stick, over 1qt low, this thing never uses oil! Guess it does now, I never check it, if it starts using it, its gone! I am starting to think maybe bad turbo making noises and has blown seal? Might be something to check!My 6.5 acts just like yours, no blow-by from the oil fill tube, hazing from CDR valve if taken off while running can be seen.

I'd also check all the other external suspect places for leaks, because it may look like it doesn't leak bad but they do. Oil filter adaptor, block cooler connections, cooler lines, turbo drain connections, and lastly, the stupid copper gasket on the oil drain plug, used to be my last leak to fix.

[Mainous]

Just wanted to add my $.02 worth on this. I would tend to rule out the valve guides for two reasons. First, you don't mention smoke on start up. This is the true sign of bad guides on a gasser or diesel. 2nd, and probably the strongest argument against the guides is that you have to remember that the intake runners are pressurized when the engine is running up the road. The more boost the more pressure. If you think about it, if the valves were loose in the guides it should actually give you more blow by rather than burn oil.
I think where John is headed with the air filter is a more likely cause. The turbo creates a tremendous amount of vacuum at the CDR and air filter. Keeping the filter clean should help to keep the engine from burning oil. However, even with a clean filter a huge amount of air is still coiming out of the engine via the CDR. I don't know about everyone else but I try to keep my engine as clean as possible and I can clean the oil off the lower part of the turbo and it will be back in less than a month. My theory is the oil is being sucked through the CDR and sent right into the intake to be burnt. John8662's info supports this.
Even with a new motor with gapless rings I still burn about a quart between changes.

[markrinker]

Has anyone cured (or lessened) high oil consumption by switching from OEM paper filters to a K&N style oiled cloth filter?

[Mainous]

Mark,

I run a K&N.

[JohnC]

Originally posted by Mainous:
The turbo creates a tremendous amount of vacuum at the CDR and air filter. Keeping the filter clean should help to keep the engine from burning oil. However, even with a clean filter a huge amount of air is still coiming out of the engine via the CDR.While this would seem to be the case, the purpose of the CDR is to regulate the amount of vacuum applied to the crankcase. The amount available actually increases with airflow, so the difference between low restriction-high airflow and high restriction-low(er) airflow is minimal. If the CDR is doing its job, there should not be a appreciable increase in crankcase vacuum either way.

Either way, a crankcase pressure check should tell what's going on.

[David_Jennings]

Intake manifold gasket?