Tobago TB-200
Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 25; Flight Crew Total 4975; Flight Crew Type 825
Troubleshooting
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Provided Assistance; Flight Crew Diverted; Flight Crew Landed As Precaution; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Overcame Equipment Problem; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
Engine began to surge and have intermittent low power. Although the aircraft did not exhibit any signs of icing I suspected potential ice or water ingestion into engine air intake. I immediately [notified] ATC and asked for radar vectors to ZZZ. As the engine surged low; the vacuum system shuddered and caused the directional gyro to work sporadically. After two unsuccessful attempts to track inbound on most direct approach into ZZZ; I was able to conduct a successful landing at minimums into the airfield. This event would not have reached a successful conclusion if not for the incredible and efficient support by ZZZ Approach. Upon post flight inspection; aircraft engine air intake rubber gasket protrusion caused a small edge that caused water and eventual ice accumulation.  I will reach out to the filter kit manufacturer and send the pictures of the issue to ensure other pilots/maintainers are aware.
Pilot reported engine power loss and surging at cruise and diverted to make a precautionary landing.