Got new injectors put in and took home, return lines leaking diesel into the crankcase, got it towed back to dealership, they replaced the return lines and changed the oil. When I picked it up, noticed that the oil pressure was averaging 10 to 15 lbs. less than before. "I" changed the oil again thinking that there still might be some diesel fuel in the crankcase but still no change.Went on a 2200 mile trip, oil pressure still low, changed oil again, went on 900 mile trip, oil pressure still down. I'm thinking that the bearings got washed when the diesel was in the crankcase. Does anybody else have any ideas, or has anybody had this kind of problem. Have also complained to the dealership that they messed up the rod, main and cam bearings because the mechanic took for a 35 mile test drive with diesel fuel in the crankcase!
animal4500rvtransporter

Most people are reporting that there oil pressure and engine's are still good after getting the diesel washdown.

Some have gone another 50,000 miles with no problems after repair.

But that dosen't mean you couldn't have problem's, I would take it back to dealer, report your concern's and have it documented that psi is lower.

You might want to have them put a mechanical oil pressure guage on the truck to verify that the factory guage is still working properly.

Maybe it's just the sending unit that happen's to be bad or the guage itself.

Are your lower psi #'s at idle only or at upper rpm's too.

Dosen't say what year your truck is, but most report 25-30 psi at idle and around 60 psi at 2,000 rpm's

DD

.

2004 lb7 with 90000 miles with 4.78 gears . The oil pressure at idle before was 25/28 psi, now it is 20 psi. At 2300 rpm, at 65 mph, before was 65/70 psi, now 55/60 psi. In a hard pull going over Monteagle and Jelico Mountains, at 45/50 mph, in overdrive, between 2600/2800 rpm, before was 60/65 psi, now it's between 45/50 psi. This is where my concern is, when I get into a hard pull. Because I was planning on getting at least 350,000 to 400,000 miles out of this engine to justify the cost of the truck.
animal4500rvtransporter
15w40 rotella oil guard by-pass filter
crankcase holds 16 qts. oil

Your pressures are lower than what you had but not terriblly low.

I think your going to have a tough time convincing the dealer of a problem.

The engine's have a 100,000 mile warranty so I would bring it to the dealer and have it written up that you have a concern over lower oil psi. At least that way if you have problem's later you could atleast go back and tell tham I told you so.

You said that at 65 your doing 2,300 rpm's at 60 psi which is what I have for psi at that rpm too, but then you say that at 45/50 in overdrive your between 2,600/2,800 rpm's at 45/50 psi. How are you getting a higher rpm at a slower speed while still in overdrive ? If the TC is locked you should be going faster at that rpm or have at least of downshifted out of overdrive.

And have the sending unit checked, I had mine replaced because of eratic reading's. I had normal psi at idle one minute and then 5 psi at idle next with "low oil pressure" message in DIC and bell ringing.

DD

.

I hold the speed at 45 to 50mph because of the curvy roads.these 4500 trucks aren't noted for their road handling abilities. When I go out west to Wyoming or Utah, I do 65 mph up and down the mountains. But I haven't been out west since I had this work done, so I don't know what the oil pressure would be on a long stretch of highway.
Thanks, animal4500rvtransporter

Got new injectors put in and took home, return lines leaking diesel into the crankcase, got it towed back to dealership, they replaced the return lines and changed the oil. When I picked it up, noticed that the oil pressure was averaging 10 to 15 lbs. less than before. "I" changed the oil again thinking that there still might be some diesel fuel in the crankcase but still no change.Went on a 2200 mile trip, oil pressure still low, changed oil again, went on 900 mile trip, oil pressure still down. I'm thinking that the bearings got washed when the diesel was in the crankcase. Does anybody else have any ideas, or has anybody had this kind of problem. Have also complained to the dealership that they messed up the rod, main and cam bearings because the mechanic took for a 35 mile test drive with diesel fuel in the crankcase!
animal4500rvtransporter

Same happened to mine 1 1/2 years ago. 3 seperate injector failures in just a few months. Each time ,lower oil pressure. GM insisted it wouldnt hurt anything. Long story short::: Motor blew within several thousand miles after the last failure. Sounded like the whole bottom let loose. Diesel fuel "DOES NOT LUBRICATE" bearings.