1st wish me luck. I have a 2007 Colorado 2.9 4x4 and I have a p0017 code and decided to change the timing chain myself . My question is when checking the chain and I turn the engine with a socket the timing chain is tight but as I turn it it will be so loose but will get tight again as I continue to turn the engine. Its tight then very very loose then tight then loose. Is this normal?