I am about to have my 5th timing chain installed into my 10' Enclave. I know, 1st time shame on them, 2nd time shame on you. My wife loves her car and she wants to keep it, It is paid for. The first timing chain failed at 92k miles. I was able to get GM to cover a part of the cost of replacement. Number 2 failed. The warranty was over and I was told that this is a common concern for the Enclave. I told the wife I am done dumping money into this car. Well she won the battle and we yet again replaced the timing chain. The third chain snapped within 90 days. It was covered by warranty. Now the 4th chain appears to be bad and we are scheduled to have it replace...I lost the battle yet again. With the cost of cars in today's market, we cannot afford to take on a new car payment. After the 2nd fault, we were advised to be sure to change the oil on a consistent basis at no more them 7k miles. After the 4th chain was put in it was suggested to change it every 5k miles. We followed that procedure but now we are in the same boat as before. After further research, I have been told that the 3.6L engine was notorious for burning oil and that GM replaced the gasket on the right bank on the crank case that reduces the amount of oil burn off due to the PCV System. Everything I find is saying that the chain is failing due to heat and lack of oil in the engine. Is there a possibility of a second component is causing the chains to stretch? I am tired of the expense of having to change out a timing chain every 18 months. Any advice would be appreciated.