I was curious on the opinions here on the use of seafoam to flush the oil system before an oil change. I have used the product before on gas engines with decent results. With a diesel engine being a more "dirty" engine and reading about possible valve and lifter bores becoming varnished with burnt oil on top of not knowing the exact history of my engine I was considering dumping a can in the motor oil and letting it do its thing to clean the oil system. Any thoughts? Thanks.

Best way to get the engine clean. Go out warm it up completely in the evening come home and drop the drain plug and oil filter. Go to bed. Now in the morning install the new filter and the drain plug. Now fill with oil. It will be cleaner oil in the crankcase. The biggest thing it takes a lot of time to drain the oil cooler and passages out. The over night method doesn't require anything but time. 

 

The only place I ever used seafoam in is stabilizing gasoline for storage, boat, mower, etc, instead of using stabil. Seen some bad reviews on staible, quit using a years ago along with WD-40, switch to PB blast.

@Dieselfuture PB blaster is the stuff! We have plenty of rusty farm equipment sitting around. Some thing only get used once a year but ya have to have it so the PB comes in handy often.

 I didn't know that seafoam would stabilize gasoline for storage. If so I'll have to put some in my generator. I'm out of stabil anyway, was planning on buying some but I have seafoam on hand.

Never have used anything to flush oil before a change.  But use Marvel Mystery Oil (MMO) for all fuel stabilization and fuel system cleaning in all my toys.  I've heard of others using MMO for oil flush and even bottle recommends for that but never done it myself.