Oil for E23 728

The engine has over 300. 000 km and I hear some ticking an can se some smoke when high RPM. I have changed the sparkplugs and the old ones was not good. I have also put some injectorcleaner in the gastank, that did help. Now for the oil, I thinking of using Valvoline 15-40 Racing oil, any one with some tips on that?? And I am going to use some oilcleaning fluid that I put directly in the oiltank and let the motor run for some time then change the oil and filter. Have some one tryed that?? And how many litres of oil do I need for a oil change with filter??

Ps. You can answer in German

How many litres of motoroil do I need for a oil change??
I have seen that Wurth have engine cleaning fluid that you put in the oil for 10 min and then change the oil, have any one tryed it??
What kind of oil do you use on your E23??

[roadcrew666]

For the Oil Change you need 5.75 litres of oil(incl.filter change, you should change the filter). This also should stand in the owners manual. I don`t have tryed Würth cleaning fluid. I change my oil once a year or all 12 tkm, until today i have no problems with my engines, and i owned over 8 BMW`s until yet. The last BMW e34 535i i owned had run over 315tkm, and i sold the car with great running engine. I only use CASTROL Oil, prefered 10W40 or 10W60.

P.S. My English isn`t very well, i don`t use it for years.

Thanks Your english is great, I understood every word I dont have the owners manual. Do you use mineral or syntetic oil?

[roadcrew666]

I usually use CASTROL RS 10W60 or CASTROL GTX 5 10W40, i also used CASTROL GTX 7 5W40, this oils are all synthetic. You also could use a 15W40 mineral oil. I prefer Synthetic oil, and i`ve never had problems with my engines.

As I said I started by changing the sparkplugs, the old one was realy bad. I filled the petroltank with STP injector cleaning fluid. That helped, less smoke and the enging worked little better. Today I used the oil treatment from Wurth. I drove the engine hot then filled the treatment fluid into the oil. I let the car running for 15 minutes then drained the oil. The oil was realy black and some partikles came out to. I used a MAN filter and Valvoline 20-50 Racing oil Mineral, I did not find the Castrol oil you recomendet me Roadcrew but the Valvoline 20-50 is to thick for the norwegian winters so i wil find the Castrol and try that before winter. The result with the Valvoline was good, full oil presure at once and allmost no smoke so my "7" and I am happy