Members with the Cummins 6.7 ISB engine on Freightliner chassis report confusion over oil capacity, as the manual often lists 12 quarts, but the dipstick reads low even after filling to that spec. Several experienced RVers clarify that Fleetwood or Freightliner, not Cummins, typically install the dipstick and extension tube, which can affect readings. There are at least two different oil pan ...

Understanding the Context

The **Cummins ISL 425 HP** (often the ISL9 or ISL 8.9L, depending on year) is generally a **strong, reliable engine**, but like any heavy-duty diesel, it has some known issues worth factoring in—especially at higher mileages. Member Title: Cummins 600 ISX Turns Over Fine, Won’t Start Members quickly focused on the lift pump as the likely culprit when a 2008 Magna with a Cummins 600 ISX would crank but not start, especially since the emergency stop wasn’t tripped and the tank was full. Cummins ISX 600 Cranks But Won’t Start—Lift Pump or ... - iRV2 Just bought a 2024 2500 with the 6.7l Cummins.

Key Insights

It’s my first diesel. It has 4000 miles on it, question is what are your thoughts on what oil to use, Manual says 10w-30 rotella above 0* ambient temp. ( No mention of synthetic blend or full synthetic) And 5w-40 rotella full synthetic for below 0*... Fleetguard is Cummins filter brand. Cummins also recommends Valvoline Super Blue full synthetic oil but you can't go wrong with any of the big name diesel oils: Mobil Delvac, Rotella T6, Delo 400 XPS, Amsoil, etc.

Final Thoughts

As for the oil being black, it's a diesel the oil is going to be black. Best oil and filter for new 2022 6.7 Cummins? - RAM FORUM There are several threads in the Cummins engines forums about obtaining engine info direct from Cummins linked to your engine serial number . Maybe even a pdf of the engine owners manual / JMHO ; The Cummins ECM is monitoring all the engine functions , should oil pressure fall into a critical area you'd very soon be seeing engine derate and shut down warnings. Have you info on the brand of oil ...