Grinding noise on start up?
 

I have a 2011 j/k ur with 25000 miles on it. Just started making this grinding noise on start up only after sitting over night. It only does it on first start up. it won't do it again unless it completely cool off. Just started doing it about 1000 miles ago. I think it would be to early for the starter. And the oil levels are good. So what else could be the rough start. Hard to diagnose being its just an initial start thing. Has anyone else had this problem?

I have a 2009 and have noticed the same issue

My 2011 makes that same sound...It's very hard to tell what it is because it happens so intermittent. Help would be appriciated.

That is your Jeep dry starting. My 2008 does this. Apparently the motor doesn't get enough oil on start up, causing it to dry start. This is because the anti-drain back valve in your oil filter isn't working properly.

I have managed to minimize this by switching to a NAPA Gold Filter. It has a special drain back valve that keeps more oil in the filter after you shut the motor off, making it less likely for it to dry start first thing.

Other than that, I'd take it to the dealer and see what they say since you're still under your warranty. I went with the above option because I'm not under warranty and do not feel like having the dealer tell me something I don't want to hear. :gak:

Thanks for the input. Definitely will be taking it to the dealership to let them know. Hopefully nothing stupid.

I have 2011 and I have noticed the same thing. It only happened in cool or colder weather and like yours only when engine was completely cold. I have had other vehicles that did this as well, in my case it is the starter not disengaging quickly enough. The lubricant applied to the moving mechanism (I think its called the Bendix) gets stiff and and causes the starter to retract slowly.
My dealer couldn't replicate the problem cause the jeep was not at the shop long enough to cool off. I'm gonna try again next winter when they can keep it all night and hear the sound when it is cold. I havn't heard it since the weather warmed up.

Same exact thing here. Do you believe by removing the Starter, Doing the necessary cleaning & re-lubing of the Starter would eliminate the slow disengagement.?

Any thoughts on the water pump or iddler pulley going out?

I also had this problem and it went away after replacing with a mobile one oil filter.

It's the anti drain back valve. You can replace your filter only. Hardly any oil is lost when taking the filter off, maybe half a quart if that.