I've been dealing with a loud rattle on startup, hot or cold. The odd thing is the only times I have noticed this is when my battery is dead and I need to jump the car.

It sound like the timing chain is loose and slapping around. Similar sound when my tensioner died. If I rev it eventually the noise goes away, does the tensioner need to be pumped up with oil pressure?

Additionally, I've had my chain guide break before and was lucky enough for it not to damage anything So I have a new guide and am on my third tensioner.

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Yes it's hydraulic (see the oil hole), the spring to keep the ratchet function working. Could your timing chain be worn ("stretched")? Where the tensioner is at the end of it's travel or something? My intake cam sprocket jumped a gear after first fire, it made a terrible rattling noize but I did get a code so probably not that if you didn't get a code.

What type of tensioners are you buying? OEM?

 

AC Delco, the updated one. It could very well be stretched. When my chain guide went I had the timing done so it SHOULD be fine. I should add that I am running 10w30 instead of 5w30, can I run thicker oil without issue and if it is a hydraulic issue would it help?

 

Did you do a complete replacement timing chain kit? I made the mistake of using store brand timing chain kit once and the top bracket wasn't formed correctly which caused the metal part of the guide to rub against the timing chain. This made the chain rattle at startup but went away once it got some oil slung on it. Just so you know, timing chain kits can be bad right out of the box but the risk is minimized utilizing OEM. I think the OEM kits are Cloyes.