M38A1 F-head engine: how often oil change?

pduske · Post by **pduske** » Thu Mar 24, 2016 2:33 am

Hi fellows,

we all know what is written about the oil change intervals in the manuals...

...but today´s oils are of much better quality, we (I myself) drive our jeeps maximum 1.000 miles per year...

How often is an oil change neccessary?

Example: I changed oil and filter 2 years (=1.500 miles) ago... and ask myself if I should change again now...

PS: As you know this engine has not a "main-oil-stream filter" - if this has an influence on the change interval...

I appreciate your advice,

keep´em rolling

Philipp

skyjeep50 · Post by **skyjeep50** » Thu Mar 24, 2016 7:20 am

I live in snow country but I try to drive my M38 and M38A1 every chance I get year round (even tho I don't have tops for both or heaters). Not many miles accumulate per year but I change engine oil 1X per year, trans oil every 2 years, brake fluid every 2 years, coolant every 2 years and grease as needed. Breakdown of the fluids is not the concern, accumulation of dirt and water is.

Post by **wesk** » Thu Mar 24, 2016 8:36 am

Modern oils usually get to play in modern engines with computer controls for better engine management, cleaner operation and better temperature controls. None of these traits are possessed by your half century plus Willys 4 banger. In fact regular modern oils are not the best choice for your antique engine. There are several quality oils designed with the needs of old style engines in mind.

Oil gets dirty based on mileage and calendar time. 3000 miles (if driven hard), 6000 miles (if driven conservatively) or 12 months. Whichever comes first is the schedule to keep.