Engine oil

[M6Scout]

Hi folks,
I just bought an m37 and don’t know if the previous owner used detergent or non detergent engine oil. How to find out which one or best option


Thanks

[NAM VET]

If you inspect the valves after removing the side plate, it will be obvious if there is a lot of crud there. I am no expert of brining life back to long neglected and unknown engines, but you might just see what mess comes out when you drain the oil. Replace and inspect the oil filter. Then fill it with good modern oil, run to warm, and drain and again inspect again, another fill with inexpensive oil, run again, and check filter. If your motor seems to be pretty gunned up, there may be some risk in using a flush oil as perhaps dislodged junk may obstruct your oil flow to some part of your engine.

As for trying to determine what the previous owner used, it may not really change your plan to get it running safely again. What is your oil pressure. And these engines tend to bypass the filter when the pressure is less than about 40 psi, allowing unfiltered oil to circulate. You might try inserting a piece of coat hanger wire with a bent loop in the end into the drain plug opening, and see what is on it when you pull it out. Be sure the loop is full circle, so it doesn't catch on anything in the pan. Probably pretty frequent oil changes are a good idea for awhile. Tell us more about hour truck, too.

The best way to check the health of your motor is to do a compression check. Hal

[M6Scout]

Great info will do and thanks