[drcoastline]

I need some input from you engine guys, please. I have experience but I am not an engine expert.

I have a 2006 Jeep Commander Limited with the 4.7L PowerTech engine. The vehicle only has 65,000 miles and is bone stock except I swapped out the original five spoke OEM rims for the exact size six poke OEM rims . I took it in last week for some service, program the TPMS system, change the oil, replace the sway bar bushings and replace a broken manifold stud.

I have noticed over the past month a tap when the engine is cold. It slowly quiets as the engine warms, but does not go away. It just quiets down. Again, I am not an engine builder but I know enough that the sound is quieting because the gap between the block and manifold or head is closing as the engine warms.

I explain the tap to the mechanic and I think it may be a valve or lifter? My jeep was sitting at this point for some time and was more or less cold. We go to the vehicle and start it and you can hear the tap. The mechanic puts his head under the car, opens the hood and we go for a few mile test drive. He stands on the pedal several times. We get back and he goes through the expansion contraction engine getting warm. He doesn't think it is anything and once the stud is repaired it will be fine. OK fine but I hear a tap. I ask him to look into it any way to just to be sure.

Today I get a call from the shop manager that the Commander is on the lift and it needs an engine. I asked why does it need an engine? The reply was the sound is in the bottom of the engine and they believe the main bearings are going bad. Now again, I am not an engine builder but I do know that generally a bottom end rebuild could be performed. I asked why can't the bearings be replaced? The reply was I need to speak to the mechanic. I am going in the a.m. to get more information.

Am I missing something? Is there something about these engines that the bottom can not be rebuilt? The vehicle runs fine has plenty of power, to the best of my knowledge nothing has let go.

Any in put or questions to ask would be appreciated.