LB7: lots of smoke and burning oil

[OregonDMAX]

recently i have been getting a lot of smoke out of the crankcase breather and oil cap when engine is warm only 150-190* coolant temp, i separated the two PCV vents to each side and the driver side is way worse. also getting lots of smoke out of the exhaust, looks blueish/grayish/white i cant tell, just not black.

the truck idles great with no fluctuation in rpm, injector balance rates are decent with the worst one being -2.0 and -1.8 the rest around -.5 to -.8 in park.

it is also slowly burning oil as well as dripping oil on the ground out of the crankcase breathers which it has never done before in the 6 years i have owned it.

any ideas what it could be? or where to start checking? this issue stumped the only shop in town that knows what they are doing (they built whiteout aka subman's race truck).
starting to get worried and don't want it to get worse or heaven forbid blow.

 

[Bustedknuckles]

Compression test time.

 

[OregonDMAX]

what kind of numbers do i want to see on an LB7 for compression. i have a feeling my MAC compression tester wont go high enough for a diesel.

 

[ikeG]

Upper 300s would prob be normal. Kinda looking for not much variance over all 8 rather than an exact number. Theres a certain fuse to pull so you can crank it all you want but no start.

 

[TheBac]

If your tester wont work, go to Harbor Freight. They sell one that works well for Dmaxes.

 

[OregonDMAX]

my MAC is super nice but it maxes out at 300psi

anything else to check besides compression?

 

[Andrew]

subd for info my brothers lbz does the same thing

 

[Chevy1925]

Leak down test would be next

 

[OregonDMAX]

i am going to have to find a compression gauge that reads above 300 and i will start there. compression test i assume remove all the GP's and do one cylinder at a time like a gasser with plugs removed?

 

[durallymax]

I have a mityvac diesel gauge with the duramax adapter.

upper 300s is pretty common sometimes low 400s. The main thing is that you do not want a variance of more than 50psi between cylinders. Also watch how it builds pressure compared to the other cylinders.

 

[OregonDMAX]

good info thanks, i was going to do it today but its now snowing about 2" so far and i have no garage. i will report back middle of next week when i have another day off. i aosi picked up the harbor freight tester, it was $27 and it had the dmax adapter, my $250 kit didnt

so i searched and found the amazing write up that Pat did http://www.duramaxdiesels.com/forum/showthread.php?t=2091
the only question nobody answered in the 3 pages was what do you pull to disable fuel on the lb7?

 

[Dirtymaxx03]

i think a leak down test would benefit you more. All a compression check is going to tell you is if a cylinder is basically destroyed. Your truck could pass a compression test with flying colors and still be letting oil past the rings

 

[MAXX IT OUT]

good info thanks, i was going to do it today but its now snowing about 2" so far and i have no garage. i will report back middle of next week when i have another day off. i aosi picked up the harbor freight tester, it was $27 and it had the dmax adapter, my $250 kit didnt

so i searched and found the amazing write up that Pat did http://www.duramaxdiesels.com/forum/showthread.php?t=2091
the only question nobody answered in the 3 pages was what do you pull to disable fuel on the lb7?

I unpluged the FICM on mine, I don't if that is what your you should do, but i used it to prime my oil pump and to do a compression test.

 

[MACKIN]

You aren't making oil by any chance? That could cause some of the symptoms you are seeing. Just wondering wit seeing that one injector out of spec. A negative number usually ( IIR) means it's pulling fuel away

 

[OregonDMAX]

i am burning oil, its coming out the exhaust in the form of blueish smoke and also dripping on the ground out the crank breather.
im not sure why all my balance rates are so negative though

 

[Chevy1925]

I unpluged the FICM on mine, I don't if that is what your you should do, but i used it to prime my oil pump and to do a compression test.

I always unplug the ficm when doing a compression test as well. Works great

 

[OregonDMAX]

You aren't making oil by any chance? That could cause some of the symptoms you are seeing. Just wondering wit seeing that one injector out of spec. A negative number usually ( IIR) means it's pulling fuel away

You got me second guessing my balance rate test so I double checked. The park and drive test were almost tue same which was weird. First one is in park second is in drive.

Edit: not sure now, phone updated photo album app this morning so they might be backwards. Either way

 

[MACKIN]

One still shows out of spec BUT just do a wick test on your oil to rule it out. I doubt you have that issue ,making oil, was just a thought seeing your balance rates and symptoms.

 

[OregonDMAX]

What would cause one to be so completely different then the rest. With them all being negative and one really high positive.

 

[Yngdmax92]

could it possibly be the turbo on its way out? If the seal is bad in the turbo you would be burning oil and if it was spooling up incorrectly or not creating the correct amount of boost then it would smoke alot to just to think