Okay so I’m about 3 months into the disco life style and I can say I’ve learned a lot. But what I’ve also learned is that oil choice for these tanks can be not only engine sound specific but climate specific as well.

I’m having some loud knocking noise when engine warms up and I feel it’s from my 5W30 oil change.

id like to know if I should keep it for the winter and maybe add an additive if suggested or change it completely to an oil you all know will settle the knock.

please help.

 

In TX I’d NEVER run any 5w30/5w40 oil!!!

I run Rotella 15w40 oil in all my D1/D2’s.

 

there is at least three diff types... is this what you all recommend?

 

Hey BEST...not to jack the thread, I had been using 10w40 before I had the engine completely rebuilt. When I got it back they recomended Valvoline 20w50 oil because of the type of motor it was for push rod & flat tappet. It also has a high zinc content. So thats what I've been using for the last couple oil changed. Seems fine. what do you think ?

 

I’ve run 20w50 before, but I prefer 15w40

 

Same. My D2 has a Turner 4.6 in it. Seat of the pants says 15w40 vs 20w50. It's seen 0'F to 105'F and the Shell 15w40 seems to keep things really smooth and quite.

 

15/40 here too in the Pacific Northwest I would think a 5/30 is too light.

 

What the difference between T4 and T5

 

T4 is conventional
T5 is semi synthetic
T6 is full synthetic

I usually pick up whats cheaper and change ~3,000 miles.

 

Diesel oil is not the best oil for a gas engine. Viscosity of 15W40 is nearly the same as 5W40 at operating temp. Diesel oils contain additives which can damage your catalytic converter. I tried it for many months and it did not heal the knocking nor reduce any leaks. 15W oil when cold converts vibration into heat, because it is very heavy at low temps compared to 5W oil, but when hot the difference is minor. What treats the knocking best per my experience is frequent engine flushes and oil changes and keeping oil temps lower (adding an oil cooler). Fresh oil kills the knocking instantly, it comes back when it is time for an oil change. I use 10W40 (Castrol GTX High Mileage) and that isn't much more expensive. I will go back to 5W40 next time and let's see what happens.