Blackbob

My moms 89" 300 SEL has a vavle tran problem. Well last night when we went to Merrit Island to get a car. On the way there the oil was a little low(abut half way down). But we didn't realize it till we got there. Anyway, my mom promtly went to the local gas station in the area of the car we bought. Purchased some oil and was on our way home. This morning I checked and replaced all fiveplugs because somewhere between the time we got there and back. The car started running "wierd" almost like it was misfiring. I'm thinking "man I hope she didn't drop a vavle." Wich I'm positive she didn't becuase there's no sound of metal in the last cylinder. After replacing the old plugs with new ones here's what I saw, the #6 plug is cacked in oil. According to the plug diagram in my haynes manual it says oil depoisitis something about it either being slipping past the piston itself(rings) or vavle seating. I'm pretty sure it's vavle seating. Because it doesn't burn that much oil. But I did notice it goes low fairly quickly but not fast enough for it to be the piston rings.I checked the other 5 plugs as well. They where placed under "too hott" also caused by either poor valve management ,so far as fuel to air ratio in the cylinder or cooling. So in a way my moms car isn't having all that bad of a problem. Just annoying,however it's firing on 5 sounds like. The even more messed up thing is that when the car was originally purchased(few months ago). It needed a new head gasket,fine,no big deal was fixed and all. But the mechanic my mom had do the job claimed he went over the vavle tran and checked everything. Obviously not the case now that we are in this perdicament. The car always burned a little oil but went unnoticed because never showed so far as seeing it out of the muffler. You know like black smoke or nothing.So anyone have any suggestions along with a better mechanic in the Orlando area while we're at it?

~BB~