Duramax OCI question

[clinebarger]

My '06 Duramax has 293,000 miles, EGR blocked, PCV intact, M1-303 filter. Have ran Delvac 1300 15w/40 since new on a 7,500 OCI. UOA came back great at 200,000 miles, Have not had a UOA done since.

Had 3 gallons left of the Delvac, Went shopping to stock up. Autozone is running a special on Mobil 1 Turbo Diesel Truck 5w/40 for $12.99 a gallon, Which is cheaper than the stock of Delvac I bought a couple years ago. Bought 24 gallons of M1 TDT so far.

The question is...What OCI should I use now without UOA's? I can change my OLM with HP-Tuners.

 

[A_Harman]

At least as far as what you were running with Delvac 1300. You probably could have been going much farther. Duramax's are famous for being easy on the oil.

Hopefully DNewton will chime in. He has an extensive database on Duramax oil analyses.

 

[dnewton3]

To be honest, none of us can really tell you exactly how far to run the OCI; only a UOA can do that. And a UOA every 100k miles really isn't much to hang one's hat on ... I can tell you that the stock OLM is generally conservative, and often will show a 10-12k mile OCI under the right conditions. Presuming the engine is in good shape (no significant contaminant intrusion) then 10k miles would be the absolute minimum I'd consider. Given your blocked EGR, 15k miles would not be unreasonable, but a UOA would be a good idea to confirm it.

24 gallons of TDT? Geezzzz ... Get one more gallon and you'll have enough for 10 OCIs. Then that would likely cover the next 100k miles.

Love those LBZs!

 

[morepwr]

Look up dnewton3's oil analysis posts on the Duramax. So much great info in there! I run 10K OCI in my 2004 LB7.

 

[BoiseRob]

morepwr, have you done any UOAs on your LB7? They're a good way to check the health of the LB7 injectors which have a known weakness. If you have, did they ever show fuel dilution?

Just Curious...

Rob

 

[morepwr]

Originally Posted By: BoiseRob
morepwr, have you done any UOAs on your LB7? They're a good way to check the health of the LB7 injectors which have a known weakness. If you have, did they ever show fuel dilution?

Just Curious...

Rob


Rob,

I havent done a UOA in a while. The injectors have been replaced and I have a lift pump with extra filtering on the fuel system now. It seems to be very happy but I plan on doing another UOA once I get farther into this latest oil.

 

[clinebarger]

Thanks dnewton3.
Just used the last of the Delvac, I guess I will have a UOA done after a 7,500 mile run & report back the results.
Now that I've altered the OLM, It's just a miles counter, Not that mine ever acted like an "algorithm based monitor" when it was stock, 10K every time.