Hi Guys

I'm new to this sight and thoughtI would try to get some help here. I have an 06 Colorado
3.5 I-5 11000 miles. Running ams oil. I have only owned the truck about 7 weeks. When I start the truck I some times get a lifter noise. It sounds like a deisl. It only lasts a few seconds and goes away. It does'nt do this on every start up only some times. Cold or hot doesn't make any differance. What's the deal?

 

The colorado with the 3.5L vortec for 06 models, which we have, contain hydraulic lifters. which use oil pressure to maintain constant contact with the rocker arms and the valve rods. you will hear that sound right when you start it up due to the oil not being completely circulated through the engine. now it not happening all the time i have no idea. if you start the truck and let it run for about 15 seconds then shut it off, and immediatly start it agian, you wont hear the sound. hope this helps.

 

The best thing to do is have a reliable mechanic look at the car - also check the oil level, if not done so already; the engine may need some minor repair, or a rebuilding; the mechanic can determine that

 

Welcome to the Forum,

some lifter noise is normal and as dave65467 pointed out the engine does start dry and takes a few seconds for the oil to pump up.
sometimes the oil will drain down other times not so, so you get the tapping or clatter at start up.
Make sure you are using the correct viscosity of oil for your vehicle and that it is not needing a oil change...

 

try using thinner synthetic oil, the ams oil u use may be too thick and taking a while to get there