I am a victim of an intentional cover up of foundational issue of a property purchased 5 yrs ago, can I still sue seller?

This appears to be an issue of a latent defect. You would have to prove that the Seller new about it and did not disclose it. This can be hard to prove unless the Seller is a contractor or developer and built the home. Did you have the property inspected by a professional home inspector before purchasing it? Usually, the home inspection can help uncover latent defects not easily seen by the untrained eye. You should speak with an attorney and discuss all the details to determine the strength of your case.