I was cold starting my car one morning (25 degrees F) and it started up for maybe half a second and engine made a thudding noise and died. Here is the sound it is making now when cracking. Just looking at where to start. Does it sound like a timing chain issue? Possible broken chain guide?

Appreciate the replies!

 

That’s a six second snippet and hard to piece together a total event here but it does sound like it is struggling.

is your battery healthy? Does the behavior replicate in a warm garage?

What year is your car and do you know if it’s in the affected range of the soft idler gear issue?
if so this could mean it has finally jumped time - they way to check is to turn the crank to 305 degrees and remove one cam sensor per bank. You should be looking at a dot centered on each hole. Usually this represent itself with many many signals of something is not right before the actual failure such as rattling noises, etc…

 

Thank you for the info, I will definitely pull the cam sensors and check the timing marks. It is a 2011 GL450. When cranking it sounds like it lacks compression. It doesn’t even try to start. I didn’t hear any rattling or knocking before this event.

battery is also fine no issue there.