So I went to cold start my car today. It was turning over, about to start. Normally it takes a few cranks when its cold and in the AM. Was cranking as normal. Then it started making a weird sound and would not start.

When I crank it over now, it makes a strange noise along with the starter crank. It makes a kind of light thud thud thud sound ontop of the starter cranking.

Anyone know what this could be? Did I break a timing chain? I did have a rattle at cold startup(just for 1-2 secs after start). Seams strange.. No codes or anything

 

Sounds like either you broke a timing chain or a timing chain tensioner failed and the chain skipped a couple of teeth. The rattle at cold startup is particularly telling - a classic sign of a failed tensioner. I wouldn't try starting the car again until you get it looked at.

 

Well I did just try it again. lol

Its turning, kinda of speeding up then slowing down. Seams to shake the car like its about to start.

 

Update: It flooded due to bad plugs. Shop replaced spark plugs and everything is smooth now