low oil pressure

[Originalguy28144]

I just purchased a 2003 duramax 2500 4x4 crew cab 6600 turbo diesel. I just had 8 new fuel injectors installed...the oil pressure was in the red and the warning light/alarm came on. Fuel injectors were leaking. When I got the truck back from dealer after installing the new injectors, the oil pressure with warm engine at idle is at the first notch above red (approx 16psi). When I pull a 5th wheel the oil pressure needle is between the red line and the first white line. (Approx 10-14psi). Another dealer used a manuel guage to determine the oil pressue. It is 16 psi at idle. (not towing) Since GM says 14psi and above is ok there is nothing they know to do. I was hoping to pull my 5th wheel to the mountains but I am afraid the truck will not make it. On the highway the oil pressure is between 30-60psi. After $5,000 for new injectors and another $2,500 for other repairs and now I am afraid to drive the truck since the engine may blow. The truck has 131,000 miles. There is also electrical problems but the diagnostics say everything is fine. It has been in the shop for repairs 4 out of 7 weeks. ADVICE PLEASE !!!

[DmaxMaverick]

Welcome to the Forums!

Those 8 injectors should have been covered under warranty. The extended injector warranty is 7 years or 200K. The bulletin states 2001 and 2002, and some 2003 trucks. If your truck had the symptoms of the bulletin, it should have been covered.

After the injector replacement, did they, or you, change the oil? If not, that could be your current problem. Leaking injectors cause fuel to enter the crankcase. Fuel diluted oil will cause low oil pressure, and is described as a symptom in the bulletin. If the oil pressure is still low after the replacement, and it has fresh oil, damage was done, and the engine needs replacement, on GM's tab.

14 PSI at idle is not the problem. The problem is, the pressure was OK before the injector issue, and now it is low. Something happened to cause the low pressure, and the dealer should be looking for the cause.

[Originalguy28144]

After 2 weeks I was able to get GM to pay for the injectors. I was told the injectors were leaking fuel into the oil when the injector problem was discovered and that the diesel fuel mixed with the oil was causing the low pressure at that time.
The oil was NOT changed after the injector replacement. Thanks for the advice...I will have them change the oil while it is in for service. Hopefully this will solve the problem.

[DmaxMaverick]

Thanks for the reply.

Glad to here GM took care of the injectors. Some cases on the 2003's required a fight to get it. Change that oil ASAP. If it hasn't been changed since the injector replacement, my bet it is the source of your low OP. So far, there's been no reports of engine damage due to short running with the fuel contamination, but I haven't heard of any long term running. Keep us posted on what your future holds. How many miles driving like this?

Also, what electrical problems are you having? Although these things are computerized nightmares to some folks, there are very few graemlins that get away. Troubleshooting and repair has proven to be quite simple, overall. If they are major issues, start another thread specific to that.

Also, be sure to check out the Duramax 6600 Diesel Page (http://www.thedieselpage.com/duramax6600.htm). Lots of really good articles there, and important info and options for secondary fuel filtration.

[Originalguy28144]

I have probably driven around 500 miles since the injectors were replaced. The truck is currently in the shop for other repairs and trying to determine why the oil pressure is low. They are changing the oil now. I will let you know what the results are. Thanks for the advice. My truck is a very early 2003 model , guess thats why the carry over from previous model years injector problem.

[escobar71]

I'm sorry to revive this old thread, but I seem to be having the same troubles. I have an '04 LB7 with approx 70000 miles. The first set of injectors (2,4,6,8) were replaced under warranty due to one of them leaking, then the other set (1,3,5,7) were replaced due to fuel being in the oil. The oil was changed after the 2nd incident. Now after about 1800 miles, my oil pressure, when cold, runs at least 60 and higher; after it is warm, it drops to a little under 30 at idle to 45-50 when cruising on the highway. The oil doesn't smell of diesel. Should I have the dealer look at the lower oil pressure? Should I even be concerned? The oil still looks brand new.

[jbplock]

... my oil pressure, when cold, runs at least 60 and higher; after it is warm, it drops to a little under 30 at idle to 45-50 when cruising on the highway...

Sounds about right ... When cold my 03 LB7 runs 60-80 psi; Hot idle is a shade under 30psi and 60 psi at 2100 rpm (hot)

[ktingey]

I'm going through the same nightmare with my 03 2500 duramax. We blew one of the head gaskets the end of june. A week ago I got it out of the shop but the oil pressures will only stay up for only 15-20 minutes of driving. Then it drops to nothing. The shop stated we should just go ahead and order a new engine and it's not worth digging into the lower end of the engine. I took the truck to another shop and right off the bat we could smell fuel on the oil dipstick. We thought it might be the injectors were not seated correctly or the return lines were leaking. They just mentioned those all checked out OK. Does anyone have any other ideas? I can't afford a new engine!

Thanks!!

[DmaxMaverick]

I'm going through the same nightmare with my 03 2500 duramax. We blew one of the head gaskets the end of june. A week ago I got it out of the shop but the oil pressures will only stay up for only 15-20 minutes of driving. Then it drops to nothing. The shop stated we should just go ahead and order a new engine and it's not worth digging into the lower end of the engine. I took the truck to another shop and right off the bat we could smell fuel on the oil dipstick. We thought it might be the injectors were not seated correctly or the return lines were leaking. They just mentioned those all checked out OK. Does anyone have any other ideas? I can't afford a new engine!

Thanks!!

Leaky injectors or cups take a long while to fill the crankcase enough to be noticed, much more than a week in most cases. The return lines can do it in a hurry. Sounds like the shop that did the head gaskets either failed to seal the return lines, or broke one/some during the job. That's on them, for a bad job. There's likely NOTHING wrong with the bottom end of the engine, unless you ran it a lot with contaminated oil and low pressure.