Write up a list of pros and cons. Things you should consider:
Cost of selling (advertising costs, agent costs, auctioneer costs, any taxes, charges, capital gains etc).
How much the property is likely to sell for in the current market. Is this a gain or a loss from when you bought?
Can you increase your rental yield on the current property? Include white goods, cable tv, etc for a price?
Can you articifically increase the capital value of the property? Maybe gain an extra car spot from a carless neighbour, get active on the commitee to improve landscaping, design, privacy etc in the building. Think creative.
CG and rental trends in the area. Chances of these going in your favour vs against you if you continue to hold?
How much does the property actually cost you per year after tax rebates/minimisation?
You may find that you’re throwing money into a lost cause, or on the otherhand you may find opportunities to make it a better investment.