Knocking sound at cold start

I have an ‘04 grand Cherokee just coming up on 100k. Sometimes when I start it after sitting overnight there’s a ticking sound. It’s more of a tick instead of a knock, couldn’t edit the subject line. It goes away within a few minutes tops sometimes even quicker.. I’ve gotten a few different opinions on what it could be, but just wondering what you guys think and if it’s something I can prevent or not. Thx

 

How about a better explanation of this "knock"? A lifter that the oil has drained out has a ticking noise where a knock could be a rod knocking. If it is more like a rod knock then I would suggest a thicker oil and see if that helps. On my Dodge ram it starts with a tick and goes away shortly and has for about the last 40K. After an oil change it will start up and stay quiet for a 1000 or so miles then it starts ticking again. Another additive you might try would be Rislone which is supposed to clean out clogged oil galleys. My Jeep 258 had a tick at startup that eventually went away after a few years of using Rotella 15W-40 oil.

 

A tick that resolves itself pretty quickly I would also suspect a lifter.
If it goes away once the engine is warm I would lean towards something like piston slap where as the engine warms up the metal expands and the tolerances become less and the sound goes away or is no longer noticable.
You don't not mention which engine you have, if it's the 4.0 liter inline 6 they are renowned for having a "tick" that is often said to be a lifter. My "tick" ended up being piston slap, but mine did not go away when warm and had over 180K miles.

 

Sorry, it’s a 4.0 liter.. it’s definitely more of a tick, like I said I tried editing out the “knock” that I originally stated but it wouldn’t let me change the subject line. It only does it maybe once every ten cold starts in the morning and goes away within a minute or two before I even start driving. I do know that a lot of these jeeps are known for having a ticking noise, but this is my first experience with one.

 

I tried uploading a video of the sound but it’s tells me that “the uploaded file does not have an allowed extension”. Anyone know what this means ? Thanks

 

Upload it to youtube and then post the link here.
I don't believe you can upload videos directly to the forum.

 

https://youtu.be/5Zr_Daluz60

Click/ knock? You guys will probably know right away what it is ..

 

The way it quited down sounds like a lifter that finally pumped up with oil. If the cam lobes are in good shape you could probably get away with dropping new lifters in.

 

My TJ has a tick like that (not as load) but only at load. Doesn't tick at start up or when sitting still or letting off the gas. Only does it when accelerating any thoughts ?

 

My tick turned out to be a cracked manifold, replaced it and the balance of the exhaust system and all is well.