Engine/Transmission (1998.5 - 2002) 1999 2500 getting fuel in the oil - how?

[Sticks]

A buddy of mine called last night and told me that his oil light came on, on the way home and when he checked the oil level it was way over full and really thin. He just did an oil change 3 weeks ago - everything was normal then.



Truck - 1999 2500, 650k miles, auto, Jammer 2 injectors, otherwise stock. Injection pump replaced in 2009.



Truck idles and runs smooth, no more or less smoke than usual. Having him change the oil and filter ASAP and monitor daily for increase to see how much, how fast.



There are only 4 ways that I can think of that you would get fuel in the oil, but I don't know what is the most common, as I have not encountered this yet.



Leaking injector nozzle, cracked head, cracked or bad seat on the cross over tube, or out the front seal on the VP44.



What says the collective here? Who is the likely suspect to check first? He was told one or more of his injectors is probably the cause, I am leaning towards the VP.



Thanks everyone!

 

[Sticks]

Seriously? Nobody?

 

[JR]

I dont know of any other ways to find out without physically tearing into it but I would suspect aftermarket injector(s) first, especially as they get some higher mileage on them. Possibly cross over tubes if he re used them when he replaced the injectors but in most cases they would leak instantly rather than later on down the road. He could re torque them just to eliminate the possibility of a loose one. Any local shops where he could get his injectors pop tested? I have heard of the seal going on the VP but never seen one in person. I suspect it would take excessive lift pump pressure or a high mileage VP with a worn out bushing to wipe the seal out. That's not a common failure. Could you pop the breather off the front gear case cover and inspect the VP? I don't know if a leaking seal would be evident or not...

 

[Sticks]

Now way to see if the VP is puking fuel w/o removing the timing cover, then run the engine.

After some research, this might be as simple as one of the o-rings on one of the injectors gave out, allowing return fuel to come up the body into the top of the head.

Over 200k on these injectors.

 

[BDaugherty]

Now way to see if the VP is puking fuel w/o removing the timing cover, then run the engine.

After some research, this might be as simple as one of the o-rings on one of the injectors gave out, allowing return fuel to come up the body into the top of the head.

Over 200k on these injectors.

Ditto. Check the oring on the injectors allowing return fuel to leak into the head.
I've seen front injector pump seals leak, but it's less common.

 

[SAndreasen]

I'd say injectors on front seal on pump is bad if a cross over tube was leaking that much it would be hard to start if it would start I had one bad o ring on the cross over on my 01 and it wasn't making oil but it was a lot harder to start took a lot of work to diagnose that one

 

[Sticks]

Well, took a look at it yesterday, and sure enough, #4 and #5 were bubbling up under the valve cover. Found a place that had O-rings and crush washers on a Sunday and got them all swapped out. In 2 days and maybe 15 miles of driving, he added 2 gallons of Diesel to his oil. At least the engine is clean now. I just hope he did not do any damage to the bearings.

First time I have been able to lift an injector straight out without having to pry up on them a touch. O-rings were solid and brittle (all of them broke into 3rds upon removal). Adjusted the valves while I was in there and sent him on his way to change his oil again & keep an eye one it. Total time working on it - 1. 7 hours. Not bad.

I should know in the next week if that was the problem or there's another leak somewhere.

One downside to trucks this old and with that many miles, anything plastic is brittle. Broke the vacuum line running across the firewall in 2 places.

 

[Vaughn MacKenzie]

Yeah had the same thing happen to me not long ago on my '98. 5, caused by cracked O-ring on #1 injector.

 

[SAndreasen]

So it was orings on the cross over tube?

 

[Sticks]

So it was orings on the cross over tube?

Post #7 - All the injector O-rings were solid/brittle. Cross over tube o-ring would only leak fuel outside the head at the injector line nuts. In retrospect I should have done those while I was there, but they all had to be pried out, and still snapped into place.

 

[SAndreasen]

OK now I seem to remember another o ring on my 95 but I can't really remember where or how it went . Also if it gets hard to start After you did this its probably a cross over tube o ring