Our diesel patrol 2.8L (1999) GU was making tapping sounds while driving, which increased as the rev's went up. A day later started it blowing a bit of white smoke. The oil pressure is good, there are no oil leaks. First mechanic said he the 'bottom end' was Ok, then looked at the top and couldnt find anything (not sure how well he looked at it though, as he didn't spend long on it). We took it to the next mechanic, he didn't look at it, just said you will need a new motor, as it would cost $1000 to open it, and $10,000 to get a new engine. Third mechanic drove it, and said needs new engine but doesn't know where the problem is. Does anyone have any advice, as I am confused as to why the oil pressure is good and the car still drives - why would I need a new engine? Is there something we could check first, as I love the car but dont have that sort of money to spend in one hit.