I took my valve cover off last weekend on the drivers side to paint it, anyway i put the cover back on and tightened all the bolts and i cranked it up and no leaks. But when you drive the car and stop and look under the hood i can see oil all over the lower intake by the egr valve. Today i loosend all the bolts and re-tightened all the bolts same deal, no leaks when i cranked up the car and even reved up the engine, but when you drive the car and pull over and pop the hood it's leaking again. What could be the problem, it keeps leaking in this one spot, could the gasket be bad, but how because when i retightened the bolts no leaks at start up, but leaks only when you drive the car. Is there more pressure build-up inside the valve covers when driving the car than at idle? Need some ideas how to stop this!!!!