I have a 98 TA My oil presure is about 40 cold 20 hot It has 90,000 miles on it I bought at 52,000 oil presure has never changed until now It stell has 40 cold revs to 80 but whan I drive it my presure will drop to 20 and will go up and down . Can be driving normal and the neddle will stay on 20 let off the gas and it will jump up to 40 get back on the gas it will go to 50 then drop back down I beleave it is the sending unit what do you guys thank.