I have a 2007 lt3 suburban with the 5.3 flexfuel. Lately when I start it up it has a loud tapping or ticking noise from the engine area. I read the to the gentleman in texas with the 2007 tahoe ltz. The temperature around here lately has been between 10 and 30 degrees. The noise has been going away after the motor warms up. The dealer thinks it might be an exhaust leak.

 

I have a '91 ford explorer that does the same thing. It seems to do it only when it's cold outside (20-30)

 

guessg
I'm the guy with the motor noise in my 07' Tahoe LT3 Flex-Fuel. To make a long story short they replaced the motor after agreeing to buy back the vehicle. They sent the motor back to the builder to try and find the problem. I have asked our dealer to let me know when they hear back from GM with the results. So far the new Tahoe equipped the same way (motor wise) is doing just fine and we love it.

The noise we had started about 300 miles. It was off and on at first which made it difficult for the service people to hear it. But when they did they tried all kinds of things per GM engineers including a complete lifter job with no results. That's when we had enough. By that time it only had 700 miles on it and the noise was getting worse. They wanted to change the motor out and send us down the road but that was unacceptable to us so GM offered to buy it back.

The noise started out with a ticking noise, like a spark plug wire arcing or a injector noise. When it got louder it sounded like a dry lifter or piston slap.

I hope it's something simple with your new vehicle so you don't have to go through the trouble we did. If it is something bad don't worry because GM will make it right for you what ever it takes. Good luck.