I bought a new 2009 Chevy Colorado in April with the 2.9L four cylinder, with less than 100 miles on it. I soon noticed a tapping noise from the engine on cold startups. It only lasts a couple of seconds, and only occurs if the engine has been sitting for several hrs. The dealer checked it and said it was due to the oil fed timing chain tensioner having to wait for oil pressure to build up. They said it is normal for this engine and will not cause any problems. I have changed the oil using the recommended 5W-30 and an AC filter that has a check valve, with no difference. It's hard to believe no damage is being done. Does anyone have any experience with the longevity of this engine? Any fixes for this issue? Thanks.
The easiest thing for you to do is go to another dealer, and test drive one of their trucks to see if it makes the same noise. If it does, then you might need to live with it.
If it doesn’t make the same noise, bring your truck directly into the shop of the dealer with the quiet truck, and tell them you just test drove that truck, and yours is making an engine noise that shouldn’t be there.