could my oil pump be going bad

Have you checked the oil level?

Low oil pressure. A bad oil pump will lose the ability to properly pump oil through your system. This will result in low oil pressure that could lead to further vehicle damage. Increased engine operating temperature. Oil reduces the friction on the parts in your vehicle, which in turn keeps temperatures regulated while the vehicle is in operation. When the flow of engine oil is reduced, the parts don't remain properly lubricated and thus heat up. Increased friction leads to increased temperatures and possibly more problems down the road. Noise. Your vehicles hydraulic lifters are an important part of your engine's operation and it is important that they are adequately lubricated. When your engine is working properly these lifters are virtually silent, but when the flow of oil is cut off to the lifters they begin to make noise and wear unevenly. It is extremely expensive to have lifters replaced and extremely important they are properly lubricated. In addition to the hydraulic lifters, your valve train may begin to make noise if your oil pump begins to fail. This includes the pushrods, the seals, and valve guides. All of these parts need to be properly lubricated as well. A bad oil pump can result in a lot of additional noise from your valve train system. Lastly, your oil pump may begin to make noise if it isn't working properly. This is a less common problem than some of the others presented here. If your oil pump begins to make noise it will be a loud whining or whirring sound. This is a result of the internal gear mechanism wearing down. As it begins to fail, your oil pump could make a bit of noise. It is unlikely that most drivers will ever experience an oil pump failure, but if you experience any of these symptoms, you may need to have your vehicle checked. It is always best to repair parts as soon as you experience a problem as extended wear could lead to a reduction in your engine life.

the issue is most likely coming from the vacuum pump..it makes a ticking sound , leading you to believe a lifter noise.. apparently theres a problem with it.. but gm is giving problems with recalling the vacuum pump, even though they have come out with a redesign of it. they only want to reprogram the brake module for more vacuum.. its ridiculous..