Smell the oil, if it smells like fuel its your injectors. When my injectors went I noticed that my oil pressure was really low. Hope this helps.

 

Yeah--sounds like injectors if you smell fuel on your stick.Maybe you need to find a dealer with a better diesel tech.

 

Hmmm, what kind of oil is it, is it 5w 40? If it is, then the viscosity might by to low.

 

blotting the oildipstick on a paper towell is a good way to tell if there's fuel in there.

5w40 is what i run, and hasn't gotten me worried or tripped an idiot light.

 

Thanks guys. I checked the oil dipstick and sure enough it smells like fuel. We'll see how long this takes to get fixed. At least it's covered under the 100k mile motor warranty.

 

Interesting. I dont think too many LLYs have lost injectors. Keep us informed.

 

This is the second problem within the last one thousand miles. First it was a fuel filter (or so they say), now I'm cruising down the road at 50 mph and the oil pressure drops from 55 psi to 30 psi and the DIC warns of "Low oil pressure". Runs fine for a bit then happens again. Now the engine idiot light is on and I don't have a scanner.

I checked the oil level and all is well but really black (only one thousand miles since the last oil change). Any ideas? Could it be the injectors going bad?

I haven't been real satisfied with the long term stability of the truck, it has only 43,000 miles and it's a POS in my opinion so far (no overheating though). I don't abuse it. I change the oil every 3K and maintain everything. I do pull a 5th wheel which is what this was designed for but even that is starting to worry me.

Thanks for your help.

Does yoru truck normally use oil? Reason I ask is if it normally uses say a qurt in 1,000 miles and you checked it and its still full, then you could be getting your oil filled w/fuel. Your truck shoudl still be under warrenty if you can find a qualified dealer to work on it, esp if its injecotrs. Dont feel bad, my trucks bone stock only pulled a 70cfm tow behind air compressor and mine wont stay runnign , cant knowck them all, we ally know the 6.0's are having problems and a lot of popel on here are happy w/theirs so hope you find a dealer that cares about customer service and GITS R DONE

 

My truck never uses oil between changes (every 3K) and I check it pretty often. I can definitely smell diesel in the oil though on the dipstick or maybe I just like the smell of diesel....who knows. I dropped it off at the dealer tonight (of course no service appointment) so hopefully I'll have an update tomorrow evening. I'm so ticked I even started looking at a Dodge! The motor would have to blow up before I even thought about a Furd. Thanks for your help and guidance.

 

I thought LLY injectors were external and there was no way they could put fuel in the oil?

Could someone who knows for sure enlighten us here??

Unless there's a hole in a piston, and it's blowing it down through there.

On mine with 20,000 miles on it, after 8000 miles since last change (mostly highway, light loads) my oils is still a very light tan color.

By the way the engine oil life on the DIC still reads 35% or something, however, I think I should change it soon.

 

from what i understand, the injector could periodically stick open (?) and dump so much fuel into the 'dead' cylinder that it washes it down and leaks fuel past the rings.

i think anyway

 

I just spoke to the dealer service and they said that is threw a code "P0093" which correlates to "Fuel rail pressure". They also said that this is not related to the low oil pressure that both my guage and the DIC reported. The are now going back and forth with the "GM Engineers".

GM engineers are pointing to several items, fuel rail pressure, possible injectors (slim chance), electrical issue, fuel pressure valve, etc. Does anybody have an idea as to what this could be? Is the fuel rail pressure covered under the warranty? Any TSB's on it?

I think a, gulp, Dodge may be in my future if this continues. I pull a large 5th wheel and don't want any issues going down the road.

 

The FPRV code is quite common and easily fixed. Although it rarely happens with a stock truck it is a very common almost constant occurance with trucks that are turned up into the higher hp ranges. The FPRV can be shimmed for under 20$ or it can be replaced with the PPE Race Valve, or it can be replaced with a factory one whcih will hopefully be stiffer than the weak one you've got. This way, it will not relieve so easily and you will not get the code. The oil pressure issue, I have no idea. My instinct is telling me faulty gauge but I have no grounds to base that on. I am sure the dealership will test your oil pump to see if it is working properly and maintaing adequate pressure. You may want to contact McRat and talk to him about it. He lost an oil pump a while back on Casper I believe.

 

JMG343 - thanks for the info. I was hoping it was something easy like the FPRV. I keep it stock for this reason and reliability (or so I thought) pulling the fiver. If the oil pressure does drop I'm going to put my foot to the floor and blow the sucker sky high . Maybe that will make them think about it. It does have a 100k warranty on the motor. I like the truck way to much to give up on it at only 43K miles.

 

JMG343 - thanks for the info. I was hoping it was something easy like the FPRV. I keep it stock for this reason and reliability (or so I thought) pulling the fiver. If the oil pressure does drop I'm going to put my foot to the floor and blow the sucker sky high . Maybe that will make them think about it. It does have a 100k warranty on the motor. I like the truck way to much to give up on it at only 43K miles.

No problem. As for your oil pressure plan. I would do the exact same thing . If they don't see a problem now, don't give them a choice next time. Just make sure you do it before the warranty is up. Good luck!

 

If you have (or have had) a harness box on your truck, check the pins in the bale connectors. This can cause false oil pressure errors.

However, I was doing street tuning on Casper, and was going 100mph WOT when the Low Oil Pressure warning came on. The oil pump came apart. The engine survived, but it creamed the turbo.

 

The high pressure fuel pump is gear driven. So, if the fuel seals in the HP fuel pump were leaking, the fuel could get into the crankcase, dilluting the engine oil, making it smell of diesel fuel, lowering the viscosity of the engine oil tripping the low oil pressure switch, and lowering the high pressure fuel rail fuel pressure and setting the HP fuel codes as well.

I'd have your dealer check for fuel dillution, and take a really close look at the HP fuel pump for the source of the multiple problems.

 

If you want to know if you are getting fuel dilution of your oil, get an oil analysis done. It will tell you for sure and is inexpensive.

 

I just got off the phone with the dealer service. They did an oil analysis and said everything checked out OK. There are no problems with the injectors (LLY motor). The only issue is that once the fuel rail pressure dropped 20 points which threw the code (possible bad fuel issue). They've put 50 miles on the truck with the computer hooked up and haven't found any additional codes or had any problems. They've checked all connections and haven't found a thing. He said to pick it up (free of charge) and drive the hell out of it. I'll keep you posted if something happens again. You can be sure that if the oil pressure drops again my foot goes through the floor .

 

If you have (or have had) a harness box on your truck, check the pins in the bale connectors. This can cause false oil pressure errors.

However, I was doing street tuning on Casper, and was going 100mph WOT when the Low Oil Pressure warning came on. The oil pump came apart. The engine survived, but it creamed the turbo.

this happened to me when i installed my 6 gun. the oil pressure gauge kept bouncing back and forth and the low oil pressure alarm was going off and on. i undid the wire harness and relatched it and it never happened again

 

sounds like a connection problem possibly i would think if you had oil pressure problem it would not drop then do back up i just cant see that but i have seen stuff that cant be explained

 

Well, I picked up my POS tonight, drove home 10 miles and it went into limp home mode. I didn't drive it lightly, took off from the traffic light slow and then floored it several times. After 10 miles, it started getting jumpy like it was starving for fuel and then went into limp mode (2,000 rpm @ 30 mph max) and the check engine light came on. Got it home and shut it down.

Started it back up after being shutdown for 10 minutes and it ran like a champ. Sat in the driveway at a 1,700 rpm idle for about 2 minutes and noticed that it started to starve for fuel so I floored it....the damn thing shut off. So, I let it sit for another 10 minutes shutdown. Started it back up, went through the same procedure with idling in the driveway and no problems. Took it for a ride and hit it pretty hard every chance I got with no problems.

I'm going to drive it tomorrow to work (12 miles city driving) with the check engine on to "let it gather data" for the idiots at the dealer. I'll keep you posted on what happens next. The dealer did mention that I have a 100k warranty so I really don't care what happens to the truck since it's under warranty. Thanks again for everyone's help.

 

Well, the truck had to be towed to the dealer for service. Started fine but shutdown immediately. I let it sit for a day and then she started right up and ran great. Dealer says it finally threw a code for an electrical problem (I'm thinking the #2 or #7 issue). Hopefully I'll have an update by the end of the day.

 

Let us know when you find out what's up. This is an interesting issue you have going on here. I do alot more reading than posting on this site and I haven't come across anything like what you're explaining.

 

I just got off the phone with the service guy. Now it's throwing a code P0642 (ECM - 5-volt Circuit). They've driven it 60 miles so far today and can't duplicate the problem with the scanner connected. They did see my previous 4 failure logged by the system though. They are keeping it tonight and will continue to drive it and hopefully reproduce the issue. The have disconnected and reconnected most of the electrical connections under the hood. I'm thinking lemon law now (I work as a network engineer for a large law firm fortunately). Again, I'll keep you posted.

 

Here's an update. I picked up the truck Friday 3/16. Dealer said that they disconnected all of the electrical connections that were throwing a code P0642 (ECM - 5-volt Circuit), tested pin to pin and reconnected with dielectric grease. I've been driving it since without any problems. Apparently this circuit controls the FPRV, Oil Pressure Sensor, Fuel Rail Pressure and a few more things. According to the dealer there is a bulletin about this that they didn't even know about and was internal to GM (only the GM engineers had access to it). Does anyone have access to a bulletin for this thing that can shed some light on the issue? I'm looking for the new 07 dually when they arrive at the dealers soon since I don't want more electrical issues down the line pulling the fiver.