My lb7 with 113,000 miles has white smoke/steam that comes out of the crankcase breather tube by the oil pan. Also when I pull the dipstick and open the oil filler cap I get a white steam/smoke blowing out when the truck is running. When the truck is running I can smell oil fumes. There is some oil that comes out of the breather tube by the oil pan. The truck has not used any oil between oil changes and does not smoke out of the exhaust at all. What should I do? It has been really stressing me out
Getting oil smell and white smoke LB7
- Thread starter duramax02
- Start date
First thing I would do is check the balance rates of the injectors. Do a wick check which is dropping some oil on a white paper towel and see if it fans out like there is diesel in the oil. Can you tell if your making oil as the level is climbing up the dip-stick?
Since your seeing a haze and wetness at the crankcase vent chances are that you have a bad injector leaking fuel into the crankcase. Have the injectors ever been replaced?
Since your seeing a haze and wetness at the crankcase vent chances are that you have a bad injector leaking fuel into the crankcase. Have the injectors ever been replaced?
Had injectors replaced at 67,000 miles. I just checked the oil level again and it is showing it to be 1/2 full on the dipstick.
Id go with Albert's suggestion and have a compression test done on your truck. White smoke out of the crankcase and using oil is not a sign of injector failure. Report back with the numbers you get from the compression test and we will help you as much as we can.
Original Poster says,
Says it's not using oil. Nonetheless my thought was he was diluting the oil and getting cylinder wall wash with a leaking injector allowing the crankcase to have diesel fuel introduced into the oil which will cause a blow-bye haze when the oil is hot.
I've had a second set of injectors go with less miles in my truck,unfortunately. Actually it was one and I got the whole set. Lucky me
No sense in checking balance rates or doing a wick test. Although I would but that's me. I yield to a compression check.
Maybe do both balance rates & compression test. More than likely you are going to have some holes with high balance rates & those holes will likley be low on compression.
When I checked the oil it was about 5 minutes after turning the truck off. After truck sits for a couple of hours its 3/4 of the dipstick. We are going to try to do a compression test on it tomorrow. Also could a clogged pcv sytem cause a problem? We are also going to pull off the alternator housing bracket and see if the oil seperator is not clogged.
I don't understand 3/4 of the dipstick? Is it 3/4 in the normal range or 3/4 past the normal range?
Easiest thing to do is check the balance rates and drop some oil on a white paper towel and see if it fans out. At least rule that out IMO. If it fans out ,dark,to light then you have diesel fuel in your oil.
I'm not saying that is it but the LB7 is plagued with injector issues and it's a easy diagnose or starting point. If you get no where there then do a compression check. The Duramax isn't known for bad rings or cylinder wall scoring from what I've seen under normal use causing excessive blow-bye with normal maintenance unless your in extreme condition of use.
Good luck
We finally got to do a compression test last night and all cylinders were between 310psi-345psi.
I can't recall what's normal 340 ish? If so you're with in range I believe for a motor with over a 100K.
I'd still do a balance rate check if I were you
I'd still do a balance rate check if I were you
Alldata says at least 300psi. Hoping it's a clogged pcv system. Going to pull the alternate bracket off and disassemble the oil separator. Read on alldata to drill a secondary atmospheric hole in the oil separator housing. Also will check balance rates. What should the rates be? Any other suggestions? We won't get to do this till next week.