I have started to hear some knocking noise for about 5 seconds when I first start the car in the morning. Has anyone had this problem?



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cold weather?
proper oil?
recent oil change?
high mileage?
low oil pressure?
early CTS?
late CTS?

details please .. my physic crystal ball is in the shop!

 

The CTS is a 2007 with 30k miles. There is 50% oil life remaining. It does it on cold start ups. The car has been at the dealer for a week now. They are saying that they are waiting on parts. I am going to drop by there today to see what kinds of parts take over a week to get.

 

oh yes .. I say it seriously important to know and I for one, would like to know what parts create the knocking ..





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Noise likely caused by either carbon build up or piston slap( excessive piston to cylinder wall clearance) Since you stated they are waiting for parts to come in - pistons would be my guess. Tapping type noise that lasts less than 1 min after cold start normally won't hurt anything.

 

They tell me that they are waiting on a timing chain kit?????

 

assuming the chain/gear breaks, just changing a timing chain on any car is upwards of $400, a Northstar even more .. due to the dis-assy that one has to do.

as you can guess by now, when an engine is opened for internal work, a timing chain replacement is always a great idea since its usually removed anyways .. the kits are cheap ($50 - $150) and the timing chains/gears should be replaced at some time .. most cars, at 100K miles is a darn good time and place ...

did you ask what else are they replacing or what the knock problem is all about?


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I finally got my CTS back yesterday from the dealer. They tell me the noise was from the timing chains being worn. They replaced both chains, all the guides and tensioners. Every thing seems fine now with no noise at cold startups. I guess time will tell. I still have 70k miles of waranty left. I'll just enjoy it and drive it like I stoled it and if it breaks they can fix it. LOL
Thanks for all the replies.