Has anyone had an issue with fouling plugs when using this? On the Dodge Forums (I drive a Ram as well as the EXPED) they suggest changing your plugs after the first time you run it through the brake booster. When I did my RAM, it didn't even smoke at first when I started it back up. I let it idle for almost 10 minutes with no smoke, so I hopped in to go for a drive. I put it in reverse to get out of the driveway and when I looked behind me, I couldn't see anything past the tailgate. My wife didn't know what I was doing and came running out when she saw the large cloud of smoke billowing across the yard.
I also used it on the first oil change and chunks were coming out of the drain hole.
There is a down side tho. I used it on my wife's 97 GMC Jimmy in the oil. Shortly after I changed the oil, we had an electrical problem and the truck kept stalling (not due to the seafoam). We had another vehicle so we let the Jimmy sit while I tried to troubleshoot the stalling problem. It sat for 6 or 8 months due to busy schedule, cold weather, and lack of a garage.
When I finally got it fixed (bad ignition box) it ran for 2 days them it started puking oil everywhere. It turns out the pressure relief valve in the oil pump got clogged with the oil sludge and was building too much pressure and blowing the O ring out of the filter. Once we had a couple warm days, we started it up to move it, and it didn't pop the filter off. So I guess the warm weather loosened the gunk enough to let the valve work again. Dodged a big bullet there. The motor has to be pulled to access the oil pump.
I don't doubt that letting it sit for so long with the stuff in there is what caused the problem. When we pulled the filter that it sat with, it was half full of dried sludge.