Seafoam in engine oil?

Alright so I give my Xj a seafoam treatment via throttle body now and again. But recently I have been toying with the idea of adding it to engine oil maybe a few days before changing the oil. I have done my research and it seems like all the horror stories are coming from people that add too much to their oil. If I was to add it to my oil it would be about a quarter bottle. Is this a bad thing? If so ill just dump a bottle in the gas tank and call it a day.

Alright consensus is don't put seafoam in the engine oil. Stick to throttle body and gas tank :eeks1:

Replace a quart of oil with mystery oil if you're trying to do some internal cleaning. Probably a little gentler than seafoam.

Some old timers run seafoam / berryman's B-12 all the time. Once a year or so I use it a day+ or about 500miles. Then change oil.
I also use 5qt oil + MMO

I've run about 1/2 bottle of seafoam in the crankcase a few days before an oil change before, to no ill effect. My understanding of the dangers of running seafoam in the oil is that, in severely neglected engines, it frees up a LOT of sludge very quickly and suddenly you have leaky gaskets and clogged oil pickups/passages.

At the time I ran it my 88 had about 185,000 on it but was a well-maintained engine. I had some pretty bad valvetrain noise bordering on knocking for awhile, and tried a bunch of stuff. Unfortunately when you run a bunch of stuff it's hard to point out exactly what helped - after cheapo oil+seafoam for a couple hundred miles, ~1000 miles of 5qt Rotella T6 + 1qt MMO, followed by Castrol GTX high-milage and a Mobile1 filter for another couple thousand miles she runs very quietly.

I don't think you're in any danger of hurting anything with 1/4 can a few days beforehand. It's a 4.0, after all

Thanks guys xD both my xjs are well maintained so I should be in the clear arty:

5 quarts Rotella and 1 quart MMO. Monitor the progress by shining a lite into the oil filler hole.....