LB7 power loss

[Oldsalt]

How does it smell?

How's the viscosity compare with known pure oil?

or the pyro's method:
How quick can you catch it on fire?

I am away from home at the moment will return at the end of the week.
I will check for new codes and diesel in the oil.
if there is diesel in the oil I am assuming this means I have injectors leaking.
Is that your prognosis?

[rapidoxidationman]

That's sure what it sounds like, given all the factors (LB7, 135K miles, overfull oil) but I'm not an expert. Might be worth the $$ to connect the truck to a techII scanner though.

[DmaxMaverick]

If you have fuel in the oil, a Tech II won't tell you any more about it than what you already know, the PCM is having trouble maintaining rail pressure. This can be caused by several issues including fuel filter plugging, collapsed fuel line, failed fuel filler cap, fuel injector leak, return line leak (internal or external), FRP regulator failure, pump failure, fuel contamination, or a suction-side fuel system leak (not in any specific order). A fuel system return rate test can't be performed "hands off" (with a computer/scanner), and requires a specific procedure to measure the return volume. Not difficult, but in no way "simple".

You can check the oil for fuel contamination easily. Engine at operating temperature, shut down and wait 5-10 minutes. Using a thin, white paper towel or coffee filter, pull the dipstick and allow the oil to puddle on the paper (don't wipe it). If you have fuel in the oil, it will have no problem running off the dipstick and onto the paper. If it's thick and won't "abnormally" drip onto the paper, you probably don't have fuel dilution. After about 5-10 minutes, examine the "ring" of the oil drop on the paper. Oil will create a distinct dark(er), heavy ring. Any fuel in the oil will create an outer ring stain on the paper, much lighter and thinner. Usually, by the time you have enough fuel leaking into the crankcase to cause running and/or fuel system codes, it will be significantly more than a "little overfull", and ultimately, it will dump excess volume out the PCV pipe below the engine, which will make a huge mess under the truck and coat the tailgate and a trailer you may be towing. It's quite obvious at this point.

Heavy, dark, thick engine oil may indicate another problem. If you are within a reasonable service interval, your bypass filtering system has failed, or you have another source of contamination. Excess sooting is usually the cause, and is not uncommon with some heavy power tunes (chip).

Start with the simple or cheap/free things you can check, and eliminate them as you go.

[Oldsalt]

That's sure what it sounds like, given all the factors (LB7, 135K miles, overfull oil) but I'm not an expert. Might be worth the $$ to connect the truck to a techII scanner though.

Arrived home last night and checked trouble codes. Found the following three
P0087
P0234
P1093

The oil level is about 1/2 inch above the full mark, Haven't checked for presence of diesel but suspect that it is, No Smoke when running. I am going to change oil and filters and take to mechanic.
Question, I understand when nozzle starts leaking you will get smoke. But what is leaking when the diesel goes into the oil is it the seal between the injector and cup or what.
Truck runs fine when not pulling the 5th wheel

[DmaxMaverick]

I don't suggest jumping to that conclusion, just yet. 1/2" above the full mark is still within the margin of error for a fill, and will have little, if any, affect on driveability or other noticeable concern. Have the oil tested to confirm the presence, or lack of fuel contamination. Blackstone Labs and Amsoil offer inexpensive test kits. Both return results very quickly, and will notify you by email, or a phone call, with any alarming results. Be sure to indicate on the test form you have a fuel/oil concern, and they'll let you know as soon as the results are available.

Fuel can enter the crankcase in 2 ways. The most common is a cracked or unsealed return line (under the valve cover). A close second is a cracked injector body. Neither of these will cause smoke until you have a LOT more than a 1/2" overfill, and by that time, you should notice a drop in oil pressure. The engine will also idle and run rough (no air space in the crankcase). Shortly after, it will soak the underside of the truck, bumper, tailgate, and any trailer you may be towing, with fuel/oil.

Your codes indicate:
Low fuel rail pressure
Turbo overboost
Large fuel system leak

If you find fuel in the oil, the fuel system codes indicate injector failure.

Your power loss is probably related to the overboost. When this occurs, the engine will defuel (causing power loss) and a stored DTC (P0234). The SES may come on, and in most cases, power will return to normal after about a minute of lower power driving or a restart. This is most often caused by aftermarket modifications that interrupt the wastegate control, damaged/disconnected wastegate control hose, or damaged wastegate actuator or linkage. If you have no such aftermarket boost controller (valve, blocker, etc.), check the rubber hose connecting the turbo compressor to the wastegate actuator. If you are using a boost controller, adjust it down, or remove it if it isn't adjustable (the non-adjustable ones are junk). The OEM wastegate control is 100% automatic and independent of any other system or PCM input. The wastegate is spring-loaded closed, and it is opened only by compressor output pressure to the actuator. The PCM controls boost levels via fuel mapping.

[Kennedy]

Dmax Mav has you on the right track here, but jumping to conclusions it sure sounds like a cracked injector(s) issue. Thing is, I'd expect more volume in the crankcase.

I'd check system restriction first. Could be another loaded/plugged fuuel filter. The fuel system restriction is the first place to start with 1093 and 0087 diagnosis, and rather than just changing teh filter I would suggest that you test restriction to see what it is. A filter can load up VERY quickly with a bad tank of fuel. and put you right back to square one.

[Oldsalt]

Dmax Mav has you on the right track here, but jumping to conclusions it sure sounds like a cracked injector(s) issue. Thing is, I'd expect more volume in the crankcase.

I'd check system restriction first. Could be another loaded/plugged fuuel filter. The fuel system restriction is the first place to start with 1093 and 0087 diagnosis, and rather than just changing teh filter I would suggest that you test restriction to see what it is. A filter can load up VERY quickly with a bad tank of fuel. and put you right back to square one.

I spoke with one mechanic I trust (He was a diesel mechanic with GM before going out on his own). He is pretty sure it is the injectors but would need to run some tests first. I changed the oil drained close to 11 qts and changed
both oil filters The bypass filter was plugged dirtier than I had ever seen it.
Filled with new oil run it to operating temperature, let it set for 1/2 hour checked and noted level on dipstick I will monitor for an increase in level.
While I was under the truck I noticed oil blowback along the chassis coming from rear of engine and top of transmission.
What is a nominal charge for injector replacement I have been quoted 4-5 thousand from independent and 7-8 thousand from GM.

I have been told to get another one by my wife, She has never said that before in 51 years of marriage. I am thinking I should take the offer.
Reading this blog is seems that models with the LBZ engine are the best, but I would like to find something a little newer with a year or two of factory warranty left. That would be the LMM models. What are the major differences and how is performance/mileage affected? I suspect the main differences are emission controls? Ant input from all you D/M fans would be appreciated.
I always said I would rather push a Chevy than ride in a Ford and for the first time it almost happened