Attention: TDR Forum Junkies 
jgillott
TDR MEMBER
Over the last 2 months or so, I have been losing a little bit of oil here and there out of my 2007, maybe less than 1/4 quart or so every 2 weeks (~500 miles). I had noticed that the back of the valve cover had some oil residue on it and had been assuming that the slow leak was coming from the valve cover and had intended to fix that issue once the weather got warm. I checked the oil last Saturday and it was down just a little and decided to not add any since I had planned on changing the oil and looking in to the valve cover gasket this weekend. I should also add that I have never noticed any oil marks on the ground or drips hanging from the truck.
For some reason this morning, I decided to check the oil level before I started the oil change. There was not a drop of oil on the stick. Somehow in the ~250 miles I drove this week, it lost/burned over 2 1/2 quarts of oil. Now here is the kicker for me, there is no noticeable change in the look of the oil leak on the back of the valve cover. So I went over the truck from top to bottom today. The turbo spins free with no signs of major play in the bearing or oil residue. The engine is dry from front to back with the exception of the slight residue on the back of the valve cover. Antifreeze is a clear pink with no sign of oil and no visible change in smoke level or smell of oil burning.
The only thing that I did find is that the back of the engine between the block and the bell housing is damp with oil with a few drops hanging off a couple of the rear most oil pan bolts. I can't tell for sure, but there does seem to be some oil residue on the teeth of the flywheel. In any other case, I would think that the rear seal let go, but there just doesn't seem to be enough oil under the truck to be leaking at that rate. There is absolutely no oil on the transmission, transfer case, or over the frame or under the body. I've had rear seals go bad in other vehicles and they have been completely covered in oil by the time they were losing quarts of oil. Again, there is a little oil in that area, but not what you would expect from a rear seal that would be leaking at that rate.
Is it possible that the rear seal could be the culprit in the situation I described? If not, any other suggestions on where to look? The truck is, and always has been 100% stock with the exception of gauges. It 59800 miles on it and runs perfect. I have exactly 3. 5 weeks left on the 5 year Cummins warranty and I have already made an appointment for it to go to the local dealership next week. I have always done all the work myself on my trucks, so it bothers me a little to have to take it in, but I figure that I may as well take advantage of the remaining warranty if necessary. Even though there is warranty left, I would really like to know what is going on in there so I can plan ahead.
Thanks in advance everyone.
For some reason this morning, I decided to check the oil level before I started the oil change. There was not a drop of oil on the stick. Somehow in the ~250 miles I drove this week, it lost/burned over 2 1/2 quarts of oil. Now here is the kicker for me, there is no noticeable change in the look of the oil leak on the back of the valve cover. So I went over the truck from top to bottom today. The turbo spins free with no signs of major play in the bearing or oil residue. The engine is dry from front to back with the exception of the slight residue on the back of the valve cover. Antifreeze is a clear pink with no sign of oil and no visible change in smoke level or smell of oil burning.
The only thing that I did find is that the back of the engine between the block and the bell housing is damp with oil with a few drops hanging off a couple of the rear most oil pan bolts. I can't tell for sure, but there does seem to be some oil residue on the teeth of the flywheel. In any other case, I would think that the rear seal let go, but there just doesn't seem to be enough oil under the truck to be leaking at that rate. There is absolutely no oil on the transmission, transfer case, or over the frame or under the body. I've had rear seals go bad in other vehicles and they have been completely covered in oil by the time they were losing quarts of oil. Again, there is a little oil in that area, but not what you would expect from a rear seal that would be leaking at that rate.
Is it possible that the rear seal could be the culprit in the situation I described? If not, any other suggestions on where to look? The truck is, and always has been 100% stock with the exception of gauges. It 59800 miles on it and runs perfect. I have exactly 3. 5 weeks left on the 5 year Cummins warranty and I have already made an appointment for it to go to the local dealership next week. I have always done all the work myself on my trucks, so it bothers me a little to have to take it in, but I figure that I may as well take advantage of the remaining warranty if necessary. Even though there is warranty left, I would really like to know what is going on in there so I can plan ahead.
Thanks in advance everyone.
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