hi,ca someone tel me what oil pressure my engine is suposed to have??the car is an audi a4 2.0 engine code alt(2001) i think my mecanic is trying to rip me of as he did an oil presure test and told me i have 1.5 bar(21.7psi) when i should be haveing 7bar(101.5psi) at idle,i dom t have a warning light on the car or anything,he did the test because the car has a slight ratle on idle,now he is telling me that the work is going to cost me 700£ plus another 700 for an oil pump wich he es recomending i change what do you guys think