Whenever I cold start my car I can hear a distinct rattle of some sort coming from the motor. I'm not sure if it is the timing chain tensioner, or if it is the vacuum pump rattle that many speak of, but it is driving me nuts. When the car warms up a little the rattle does go away and the engine sounds normal. I have also heard that the diesel esq sound is a characteristic from these engines, but I am not sure if this is a death rattle or what. Is there a way to test for a bad tensioner? My car has been doing this since I got it a few months ago, I hope I am not doing any damage to the motor.

 

I would also like to add that the oil is topped off and checked weekly, and the noise is far less pronounced as the death rattle videos on youtube show it to be.

 

I would pull your valve cover when cold and take a look!

 

What year and model do you have? Due to direct injection, I have often thought that my 2011 MCS had an issue. Nope. Still the same at 62k, bought used at 21k, used hard every day. Can you upload a video?

 

I did the vacuum pump test where while the engine was running and the sound was there, I pulled off the hose going to the vacuum pump, and lo and behold, aside from the loud hiss that that produced, the rattling sound was gone. All I heard was the direct injection tick which is normal for these cars. Looks like that was my problem all along, a big load off my mind.

 

Is it more of a Whirring noise?