I've got an ´85 280SE (w126 european model) with a injection 110 engine with oil cooler.
When the engine is hot it has low oil pressure on idle. That is - below 1 on the meter.
Yesterday it totally lost pressure (almost 0 on the meter) when idling after doing some kickdowns on a hot engine on my way home.
I usually drive very short trips. So it almost never runs hot. I checked the oil after the trip yesterday - but it seems it does not burn the oil.
I have 15w40 oil on it (less than 1000 miles "old")(I used to have 10w40 but changed to see if a thicker oil would do better - was that a bad idea?).
It idles around 600-700rpm in drive position, and a little more in park or neutral prosition. The engine has an unknown milage - probably around 300-400 kkm. It has a renewed head from two years ago.
What could be the culprit? Worn Crankshaft? Oil Cooler? General old age....
I'm not too nervous because it usually has enough oil pressure. Should I be worried?
Best Gunnar