true, true. i didnt think about the super size sump.

 

yeah boss it's true of most large diesels.
the detroits at work hold 45gallons each. Checking them cold ends up being 4-5 gallons off.

 

Looks like a good rule of thumb for motor oil is about 10% expansion when it goes from room temp to 200*F...

 

If you are burning that much oil than the build-up of carbon in the oil would be likely worse than if you burn less oil so changing oil is a must more then ever or you will quickly finish of whatever is left of your motor bearings.

If you don't have a lot of blow-by on the CDR or any external oil leaks then rings, valve stem seals are the best exlaination. Maybe it is time for an overhaul before something breaks.

Seb....

 

I am trying to remember your post about the cdr catch can system you built.

Did you get the blowby from the timing gear cover?
I can't imagine that much oil slobbering by there, the valve cover yeah, I've seen it slobber that amount into the intake.

If you really can't find any other source, maybe its time for an oil sample to see if it is all getting past the rings.

 

Hamberger - you lost me there pard. I understand the idea that burning more oil might create more carbon (maybe depends on whether it burns cleanly or not), but since all 10 quarts are being replaced every 1000 miles, and the carbon particles that aren't trapped by the filter will stay suspended by the oil and get carried into the combustion chambers and burned up right along with the oil, I can't see how anything is going to "build up" in the oil. It is being diluted too much and too fast with new clean oil. Like I said, I still plan on changing the filter every 3k as usual. As for the valve stem seals - I've already said (2 or 3 times now) that I just replaced them (about 6 weeks ago) and it didn't seem to make much difference. Also, the ones that I took off looked fine - they weren't cracked or hard or anything.

Deeproots - there is a significant amount of blow-by from the timing gear cover. It goes to my oil trap and I empty it at every fuel up & oil top off too. It usually has about 8 ounces or so in it (I really need to make it automatically drain back to the crank case). Very little of it is getting by the oil trap and into the intake. I know this because I've checked it. Not just once, but twice, since replacing the valve stem seals. Not sure what you mean about oil leaking from the valve cover getting in to the intake though. The intake manifold has its own separate gasket. Oil from the valve covers can leak onto the manifold, but it can't get sucked into the intake unless the intake gasket is leaking. BTW, when I replaced the valve stem seals I put new valve cover gaskets in too - they don't seem to be leaking.

I'm still open to ideas though guys. I can't seem to figure this one out. Like I said, it is leaking a little, but I've let it sit and idle and it isn't leaking at a rate anywhere near enough to get rid of a quart every 100 miles. I'm really at my wits end with this one...

 

I'd say that motor got dusted!

Thats a pretty serious ring issue.

I'd be curious to see compression test numbers, dry then wet.

-Enjoy
fh : )_~

 

I already posted the dry (cold) compression numbers - in the 320-360 psi range. I haven't tested the compression wet (warmed up), but the numbers would certanly be better, not worse. Like I said, the compression isn't stellar, but its not terrible either. Not as bad as I'd expect it to be if the rings were bad enough to be letting that much oil by...

It also doesn't start like it has low compression. I hit the GP button for 6-7 seconds and start cranking while keeping the GPs energized for another 2-3 seconds and she fires right off. Even when the temps are down in the 20's it fires up using that same sequence.

 

I would not change oil in that engine, it changes itself nevery 1000 miles. The filter should be enough.

 

I thought you werent supposed to do a wet compression test on diesels.............................or maybe it was some other kind of moter.....

 

ooooPs, Sorry missed them numbers.

I know there many factors that can changed the numbers, but they seem low to me, I would expect to see 400 or above.

To do a dry then wet compression test has nothing to do with a warmed up motor, either can be done cold or warm as long as they are done the same temp.

I like to do both cold then warm winding up with 4 numbers per cylinder to get a real good idea of whats going on.

Wet is to add a little (couple table spoons) of motor oil into the cylinder then test, it assists sealing the piston/cylinder identifying ring condition.

-Enjoy
fh : )_~

 

Do you need a special kind of tester to do a wet compression test? I thought it would damage the tester if you did it with a diesel motor for some reason....

 

Same tester, Done all the time.

-Enjoy
fh : )_~

 

huh, musta been something else then. Thanks for clearing that up for me.

 

My point exactly - no sense doing a FOURTH oil change every 3k miles...