Q: Have had oil leak for some time now. Have had it looked at but told can't find leak. Replaced sending unit but still leaks. If pan

If you have an active oil leak and cannot determine where it is coming from then the easiest way to determine where the oil leak is coming from is to have the entire engine cleaned and then add an oil leak detection dye to the engine oil. This dye will mix with the engine oil and will leak out where the oil leak is. Using a florescent light and yellow lens glasses designed to see the dye you will then be ale to see the oil leak where it starts. Then a repair can be done. Always repair the highest leak on the engine first since this will leak oil down onto the rest of the motor over time.