I have a weird clicking noise under my hood. I think that it happens so times, but may happen all the time, just not heard as loudly sometimes. I think my engine sounds like a diesel sometimes. Now, I have went for 7,000 miles without changing the oil about twice. But I think that it did that before then. Haven't I heard about this problem with the OHV engines. It has 83,400 miles on it. The oil was just changed, and it's full of oil. What could it be?